Endorsed projects

(AC)³ - ArctiC Amplification: Climate Relevant Atmospheric and SurfaCe Processes, and Feedback Mechanisms

Manfred Wendisch
Within the last 25 years a remarkable increase of the Arctic near–surface air temperature exceeding the global warming by a factor of two has been observed. This phenomenon is commonly referred to as Arctic Amplification. The warming results in rather dramatic changes of a variety of Arctic climate parameters. For example, the Arctic sea ice has declined significantly. To study processes leading to Arctic Amplification we combine the scientific expertise and competency of three German universities (Leipzig, Bremen, Cologne) and two non–university research institutes (AWI, TROPOS) in the framework of a Transregional Collaborative Research Centre TR 172 (http://ac3-tr.de/) funded by the German Research Foundation (DFG). The first approved funding period (Jan 2016 to Dec 2019) covers the time frame of YOPP. The project will deliver a major German contribution to MOSAiC. Observations from instrumentation on satellites, aircraft, tethered balloons, research vessels, and a selected set of ground–based sites will be integrated in dedicated campaigns, as well as being combined with long–term measurements. The field studies will be conducted in different seasons and meteorological conditions, covering a suitably wide range of spatial and temporal scales. They will be performed in an international context and in close collaboration with modelling activities. The latter utilize a hierarchy of process, meso–scale, regional, and global models to bridge the spatio–temporal scales from local individual processes to appropriate climate signals. The models will serve to guide the campaigns, to analyse the measurements and sensitivities, to facilitate the attribution of the origins of observed Arctic climate changes, and to test the ability of the models to reproduce.

A+5 - Arctic Earth Observation Impact Assessment

Thomas Kaminski
The project addresses the combination of earth observation (EO) data streams with a numerical model of the Arctic ocean sea-ice system using advanced data assimilation techniques. The team proposes to construct a highly flexible system for Arctic Mission Benefit Analysis (ArcMBA) that evaluates in a mathematically rigorous fashion the observational constraints through individual and groups of EO (and in situ) data products in an advanced data assimilation system. A+5 fits to the YIOO objective on the improvement of polar prediction capabilities on daily to seasonal time scales.

ACAS - Arctic Climate Across Scales

Michael Tjernström
The project seeks to improve our understanding of physical processes in the Arctic and specifically to explore what it would take to reduce the risk of summer sea-ice completely disappearing within this century. The tools to achieve this will be improved modeling across the scales from hemispheric to local and especially for the surface energy balance and clouds, and improved process-level research-grade observations by building a semipermanent atmospheric observatory on the Swedish icebreaker Oden.

ACE-SPACE - Antarctic Circumnavigation Expedition: Study of Pre-industrial-like Aerosol Climate Effects

Julia Schmale
Aerosol-cloud interactions are the least understood anthropogenic influence on climate change (IPCC, 2013). A major cause of this limited understanding is the poorly quantified state of aerosols in the pristine preindustrial atmosphere, which defines the baseline against which anthropogenic effects are calculated. The uncertainty in aerosol induced radiative forcing (± 0.7 from a mean of -0.55 W/m2) is twice the uncertainty for CO2 (± 0.35, mean +1.68 W/m2). Also, models grossly underestimate cloud solar reflectance there, by as much as 30 W/m2 during summer. We suspect it partly being due to poor representation of aerosol-cloud interactions. This project aims at reducing the uncertainty in the effects of aerosols on climate change by exploring preindustrial-like conditions which can almost only be found in the Southern Ocean. To achieve this, we will conduct ship-based measurements of aerosol microphysical and chemical characteristics as well as measurements of trace gases modulating particle characteristics and combine these with on-board remote sensing and satellite data of clouds to evaluate global climate models. The Southern Ocean is the most pristine aerosol environment on Earth, but almost the entire region remains unsampled. The ACE expedition from December 2016 to March 2017 provides a unique and unprecedented opportunity to prove or dismiss this hypothesis.

ACRE - The Antarctic Clouds and Radiation Experiments

Simon Alexander
A suite of cloud, aerosol and radiation instruments will be deployed to Macquarie Island (54°S) Davis (69°S), and onboard the Australian icebreaker (43°S - 69°S). The data collected will be used to validate satellite cloud retrievals; evaluate weather forecasting and climate models; and aid in model development. ARM deployments to Macquarie Island (MICRE, 2016-18) and onboard the Australian icebreaker (MARCUS, summer 2017-18 season) are a key component of this research project.

AdelieHRM - Influence of small-scale processes on the dynamics of the coupled atmosphere-cryosphere-ocean system on daily to seasonal timescales in the region of Adélie Land, Antarctica.

Thierry Fichefet
A high-resolution coupled atmosphere-cryosphere-ocean model will be developed and used in the Adélie Land area, Antarctica to evaluate the impacts of the high spatial and temporal resolution, explicit treatment of small-scale processes usually neglected or highly parameterized in global climate models, and coupling on the sea ice characteristics, the air-ice-ocean interactions, and the surface mass balance of the Antarctic ice sheet on daily to seasonal time scales. The effect of initial conditions on the model prediction skill will also be assessed.

ALERTNESS - Advanced Models and Weather Prediction in the Arctic: Enhanced Capacity from Observations and Polar Process Representations

Jørn Kristiansen
ALERTNESS will significantly improve AROME Arctic, the recent entry-into-service weather forecast model system at MET Norway. It is an operational convection-permitting model system dedicated to the European Arctic and one of the core models of the Year of Polar Prediction (YOPP). The project will advance challenges unique for the Arctic: The sparse conventional observation network, exploitation of satellite observations over snow and ice, atmospheric data assimilation at high latitudes, parameterization and representation of key polar processes, and the associated representation of uncertainties. The project is led by MET Norway, with co-leads from University of Bergen, the University Centre in Svalbard (UNIS), and Uni Research.

AMAW - User-driven monitoring of adverse marine and weather states, Eastern Beaufort Sea

David E. Atkinson
This project builds upon an existing one being led by Atkinson. The intent is to continue working towards improved marine weather and storm information and preparedness for ocean waves, swell and storm surge for coastal communities (Ulukhaktok, Tuktoyaktuk and Sachs Harbour) and marine operations in the western Canadian Arctic.

APP - Antarctic precipitation properties from ground-based instruments.

Nicoletta Roberto
The main focus of the project Antarctic precipitation properties from ground-based instruments (APP) is to set up an observatory for investigating precipitation in Antarctica. Characterization of effective precipitation that occurs at ground of Antarctica region, plays a crucial rules in defining and validating global climate models and numerical weather prediction model. The observatory is designed to be set up at the Italian Antarctic station Mario Zucchelli integrating the current instrumentation for weather measurements with other instruments specific for precipitation observations. In particular, a 24-GHz vertical pointing radar, Micro Rain Radar, and an optical disdrometer, Parsivel will be integrated with the advanced weather stations, radiosoundings and the ceilometer. The synergetic use of the set of instruments allows for characterizing precipitation and studying properties of Antarctic precipitation such as dimension, shapes, fall behavior, density of particles, particles size distribution, particles terminal velocity, reflectivity factor and including some information on their vertical extent. The project is for four years, it started in July 2017 and will be active until July 2020, covering the Special Observation Period (SOP) in the Southern Hemisphere of Year of Polar Predicition (YOPP) period. APP can be provide specific measurements for precipitation occurring over the Antarctic coast at high temporal resolution, in particular specific snow products such as snow rate, snow depth and their water equivalent.

APPLICATE - Advanced prediction in polar regions and beyond: Modelling, observing system design and linkages associated with a changing Arctic climate

Jung Thomas
APPLICATE will develop enhanced predictive capacity for weather and climate in the Arctic and beyond, and determine the influence of Arctic climate change on Northern Hemisphere mid-latitudes, for the benefit of policy makers, businesses and society.

APRES3 - Antarctic Precipitation, Remote Sensing from Surface and Space

Genthon Christophe
Antarctic Precipitation, Remote Sensing from Surface and Space (APRES3) is a program to acquire in situ data to characterize precipitation in Antarctica (rate, size and shape of falling snow), use the data to calibrate, validate and contribute improve satellite climatology, improve cold microphysics of water condensation in meteorological and climate models, evaluate and validate the models using satellite climatology, and finally run forecasts of precipitation changes and impact on sea-level, in time to contribute IPCC6.

ArcAIOS - Arctic Atmosphere-Ice-Ocean interactions at small and large Scales

Christine Provost
Interactions in the Arctic atmosphere-sea-ice-ocean system change the circulation/dynamics/heat in the ocean and lower atmosphere, and the thickness/distribution of sea-ice and snow. Autonomous, integrated atmosphere-ice-ocean buoy systems have been developed to provide year-round observations from the harsh and hard to access Arctic Ocean. In addition to giving a quasi-synoptic view on regional scales, these systems allow an in-depth study of local processes. Satellite observations allow additional synoptic insight and need to connect observational scales. Building on our expertise we propose to study key local processes involving sea-ice-atmosphere-ocean interaction in a large-scale context. In addition to synthesising existing autonomous observations and satellite data products in scientific analyses, the work will feedback with buoy-related programmes and support the upcoming international drift campaign MOSAiC. This project will support YOPP by evaluation of near-real-time observational systems in a long-term context.

Arctic OSSE - Evaluate and Improve the Usage of Arctic Observation for Weather and Extended Range Forecasts using OSEs and OSSEs with NGGPS. Preparation for YOPP and beyond.

Michiko Masutani (University of Maryland), David Bromwich(Ohio State University), Joseph Tribbia (National Center for Atmospheric Research), Robert Grumbine (NOAA/NWS/NCEP/EMC)
Arctic ice has declined during the last decade, and possibly related unprecedented abnormal midlatitude weather has been reported. There is evidence that a more complete Arctic observing system will improve tropical cyclone track forecast in the mid latitudes. Arctic observations require urgent research efforts for effective planning to prevent or mitigate potentially large societal and economic losses. In this project, effective observation system in the Arctic region to improve Arctic and mid-latitude extended-range forecasts will be investigated using Observing System Simulation Experiments (OSSEs). Global and Regional OSSEs and theoretical prediction can provide complementary information about requirements for future Arctic observing systems. First, OSSEs with global coverage will be conducted at relatively low resolution, and resolution will then be varied to evaluate how the observation impact depends on the model resolution and various configurations. The impact of higher resolution will be investigated with regional OSSEs with advanced physics over the Arctic. Simulated experiments with idealized observations will be conducted in the initial stage. Idealized observations are designed based on the distribution of planned potential observing systems without current technical limitations. The task will be accomplished by making the best use of the recently developed US operational weather forecast system including the Next Generation Global Prediction System (NGGPS). The Nature Run (NR), simulated ‘truth’ for the OSSEs, which is most suitable for this project, is being prepared.

ArcticInfo - Information systems in the Arctic Ocean: Drivers, architecture, and effects on the development of marine economic activities

Maaike Knol
Large investments are currently made to improve mapping, monitoring, observing and surveying capabilities in the Arctic Ocean. These new technological infrastructures widen the range of available information. This provides a basis for the growth of informed economic activities, thus stretching the boundaries of the accessible Arctic. The information systems thereby seem to play a double role. While making the Arctic more controllable and predictable, they also enlarge the potential risks and hazards associated with increasing activity. The main objective of this project is to analyze the development of information systems in the Arctic and how they affect economic decision-making. In three thematic work packages, we (1) investigate the development of Arctic information systems as socio-technical infrastructures; (2) generate deeper understanding of the complexities and challenges in the user-producer interface in Arctic information systems; (3) and explore how Arctic information systems affect economic decision-making and alters the Arctic as a zone of risk.

ARIA - Atmosphere-SeaIce Interaction in the New Arctic

Richard Davy
Arctic sea ice has undergone rapid changes in the last decade as thick, multi-year ice has been melting and replaced with thin, more dynamically-fragile first-year ice. This, coupled with a strong trend towards reduced sea-ice extent has led to a transition towards a new, blue Arctic. This brings uncertainty for atmospheric and sea-ice forecasts in the region as many aspects of air-ice coupling are poorly understood on both the small-scale and the mesoscale. In this project, we seek to improve our understanding of the importance of air-ice coupling processes for atmospheric and sea-ice forecasts by using a hierarchy-of-coupling approach. We will use an advanced sea-ice model with a realistic rheology, NeXtSIM, in combination with the Weather Research and Forecasting model and an interfacial atmospheric boundary layer model to assess coupling processes and their importance for atmospheric and sea-ice forecasts.

ASIMBO - Arctic Sea Ice Mass Balance Observatory

Thomas Krumpen
Arctic sea ice extent and thickness are rapidly decreasing, mainly due to anomalously high surface air temperatures and changes in the atmospheric circulation regime. As a consequence of the strong decline and thinning of the ice cover, ice drift accelerates and deformation increases. Consequently, ice-area exports increase out of the Arctic through Fram Strait, the main flux gate of the Arctic Ocean for sea ice. The main aim of the ASIMBO campaign is to determine the thickness of the sea ice that leaves the Fram Strait during summer months based on combined measurements of ice draft and total freeboard. ASIMBO complements the sea-ice surveys that were made in previous years, such as the TIFAX campaigns 2010, 2011, 2012, 2016, and 2017, and is thus an established monitoring campaign. The thickness measurements also have considerable potential value for satellite calibration as well as sea-ice model evaluation and development. In addition, a number of buoys will be deployed in the High Arctic, contributing to the YOPP Arctic SOP2, and basic meteorological quantities (temperature, humidity, wind) will be collected by aircraft sensors. We consider the ASIMBO measurements highly relevant for the YOPP mission to improve polar environmental prediction capacity.

ASPeCt - Antarctic Sea Ice Processes and Climate

Marilyn Raphael
A primary objective of SCAR’s expert group Antarctic Sea ice Processes and Climate (ASPeCt: http://aspect.antarctica.gov.au/) is to establish the distribution of the basic physical properties of sea ice that are important to air-sea interaction and to biological processes within the Antarctic sea-ice zone. To achieve this goal, ASPeCt has established a data-acquisition strategy of maintaining an ongoing system of quantified shipboard observations that provides statistical descriptions of sea ice and snow thickness distributions. These observations of in-situ ice characteristics, made year after year, largely during the southern spring, summer and autumn, are crucial for monitoring and understanding the maritime climate system as well as for providing verification of satellite products and model output. These observations are directly relevant to the YOPP objectives outlined in the YOPP Implementation Plan. Therefore, ASPeCt proposes to contribute its acquisition strategy and the sea-ice data so acquired, to the YOPP effort to be used, for example, for model verification and improved representation of sea ice in models.

ASPIRE - Antarctic Meteorology and Snow Research: from Process Understanding to Improved Predictions

Timo Vihma
ASPIRE will address the Antarctic atmosphere and snow. The work will result in better understanding of physical processes as well as in parameterizations and post-processing methods applicable in weather prediction.

AWARE - ARM West Antarctic Radiation Experiment

David Bromwich
The primary objective of AWARE on the West Antarctic Ice Sheet (WAIS) is to characterize the atmospheric and surface energy budget, and atmospheric thermodynamic structure as completely as possible with available logistics and instrumentation, in order to garner a data set that can be interpreted in the context of large-scale atmospheric dynamics to understand specific warming mechanisms over West Antarctica. The primary objectives of AWARE at McMurdo are (1) to empirically understand the unique Antarctic manifestations of mixed-phase clouds and aerosols, and their effect on the radiation budget, and (2) using the most advanced atmospheric instrumentation available, examine microphysical properties of clouds that have recently descended from the WAIS to Ross Island via the Ross Ice Shelf. Principal Investigator (PI): Dan Lubin, Scripps. D. Bromwich is one of four Co-PIs.

AWImet - Additional Upper Air Soundings from Neumayer, RV Polarstern and AWIPEV

Holger Schmithuesen, Marion Maturilli
http://www.awi.de/en/science/long-term-observations/atmosphere/antarctic-neumayer/meteorology/radiosondes.html https://www.awi.de/forschung/langzeit-beobachtung/atmosphaere/arktis-awipev/radiosonden.html
During the three "YOPP Special Observing Periods" we intend to launch extra radiosondes (envisaged are 4 per day) at the three AWI research platforms Neumayer (Antarctica), Polarstern (research vessel), and AWIPEV (Ny Alesund, Spitsbergen).

CAALC - Characterization of the Antarctic Atmosphere and Low Clouds

Penny Rowe
The West Antarctic Ice Sheet (WAIS) and the Antarctic Peninsula (AP) have been among the most rapidly warming regions on Earth, although the AP has more recently experienced a halt in warming. Despite the rapid change experienced in the WAIS and AP, knowledge of clouds is severely limited. In addition, clouds over the Southern Ocean are not reproduced accurately in climate models, with important implications for global climate modeling. We plan to measure atmospheric and low-cloud properties over the AP during Austral summers 2016/2017 (complete), 2017/2018, and 2018/2019, and over the WAIS during a short field campaign during Austral summer 2018/2019. Our goals are to improve our understanding of low-cloud properties, their impact on warming and sea ice concentration, and their representation in models. We are particularly interested in the frequency and effects of supercooled liquid cloud. Measurements: Standard radiosoundings will be made, measuring atmospheric pressure, temperature, humidity and winds up to 20 km. To extend the time span of soundings, we are collaborating with scientists at the Korean and Chinese stations on King George Island. In addition, several soundings will include cloud sensors capable of determining cloud height, thermodynamic phase, and droplet or ice crystal size distribution. Surface-based instruments (pyrgeometer and pyranometer) will measure broadband ultraviolet/visible and infrared radiation. Furthermore, our measurements will be complemented by additional measurements made by the Antarctic Research Group of the Universidad de Santiago de Chile (USACH), including a mini-micropulse lidar, which will remotely sense cloud height and thermodynamic phase, and spectroradiometer measurements of ultraviolet and visible radiation.

CAESAR - Cold-Air outbreak Experiment in the Sub-Arctic Region

Bart Geerts
CAESAR (Cold-Air outbreak Experiment in the Sub-Arctic Region) will deploy the US National Science Foundation NCAR C-130 aircraft to document convective clouds in the marine boundary layer (MBL) during cold-air outbreaks in the far northern Atlantic Ocean, in a region stretching from the Fram strait to the Barents Sea. The NCAR C-130 will be based in Kiruna, Sweden (KRN), and conduct research flights between 23 Feb and 7 April 2020. The payload will include dropsondes, the Wyoming Cloud Radar (WCR, three antennas, up/down and slant back), the Ka-band Profiling Radar (KPR), the Wyoming Cloud Lidar (WCL, up-looking), the (Multi-function Airborne Raman Lidar (MARLi), a microwave radiometer, a number of Optical Array Probes for precipitation particles, cloud particle spectrometers and total liquid/ice probes, the VCSEL water vapor sensor, several probes to measure the concentration and size distribution of aerosol, including cloud-active aerosol, several trace gas probes, as well as meteorological and eddy correlation flux sensors. CAESAR is expected to improve the understanding of aerosol-cloud-precipitation processes in mixed phase clouds, and its representation in regional and global climate models. These data are sorely needed since MBL clouds represent a significant challenge to NWP and climate models, especially in the high-latitude regions, as they generally are sub-grid-scale and fall in the gray zone where boundary-layer processes and convection are tightly coupled and cannot be parameterized independently.

CANDIFLOS - Characterising and Interpreting FLuxes Over Sea-ice

Ian Brooks
CANDIFLOS will develop new parameterizations of the turbulent surface fluxes of momentum, heat, and water vapour over sea ice using in situ measurements collected over a total of 18 weeks of cruise time in the Arctic Ocean. The parameterizations will be implemented in the Met Office Unified Model, in both forecast (atmosphere only) and climate (fully coupled, Hadley Centre Global Environment Model version 3, HadGEM3) versions. The impact of the new parameterizations on the surface energy budget and sea ice will be evaluated within HadGEM3.

CATS-BL - CATS – Boundary Layer Measurements in the High Arctic

Günther Heinemann, Alexander Makshtas
The goal is the generation of a new data set of in-situ observations in the high Arctic for the verification of regional climate models and process studies. We plan measurements of the atmospheric boundary layer (ABL) structure for one year (Sept. 2017–Sept. 2018) at the Russian station Cape Baranov, which is one of the northernmost observatories in the Arctic. The measurements are part of the project CATS (Changing Arctic Transpolar System) as a joint effort of AARI, Russia, and the University of Trier, Germany.

CIRRUS-HL - Cirrus in High Latitudes

Christiane Voigt
CIRRUS-HL - The airborne experiment on CIRRUS in High Latitudes with the high-altitude long-range research aircraft HALO http://www.halo.dlr.de Topic: The CIRRUS-HL experiment will deploy the research aircraft HALO together with ground stations, satellites and models to gain new insights into formation, properties and climate impact of cirrus in high northern latitudes and into aerosol (incl. aircraft) effects on cirrus. Partners/Institutions: Deutsches Zentrum für Luft- und Raumfahrt, Karlsruher Institut für Technologie, Universität Leipzig, Johannes Gutenberg-Universität Mainz, Max Planck Institut für Chemie, Ludwig- Maximilians-Universität München, Goethe-Universität Frankfurt, Ruprecht-Karls-Universität Heidelberg, Forschungszentrum Jülich, Leibniz-Institut für Troposphärenforschung, Paul Scherrer Institute, Eidgenössische Technische Hochschule Campaign location: Kiruna/Sweden and Oberpfaffenhofen/Germany Date and season: February to April 2019 Flight hours: 140h/20 flights

CLARA2 - CLouds And Radiation in the Arctic and Antarctica

Giandomenico Pace
The project CLouds And Radiation in the Arctic and Antarctica (CLARA2) aims at investigating the optical and physical properties of clouds and at determining their effects on the surface and atmospheric radiative budget. Special emphasis will be dedicated to the determination of the atmospheric vertical structure and to the role of liquid clouds. Two intensive field campaigns will be carried out: The first campaign will be based at the Thule High Arctic Atmospheric Observatory (THAAO, 76.5°N, 68.8°W) in north-western Greenland. This campaign will take place between February and April 2020 and will contribute to the third Special Observing Period of the Arctic YOPP through the characterization of the atmospheric conditions and the cloud properties. Automatic measurements will also be carried out during a full annual cycle. The second campaign will be carried out in Antarctica at the M. Zucchelli Station (MZS; 74.7°S, 164.1°E) at Terra Nova Bay during the summer season (November 2020 -– February 2021). A preliminary analysis of the data acquired during the YOPP activities of the SOP-SH at MZS (austral summer 2018 – 2019; data from other projects) will be carried out with the aim of deriving information on cloud effects and optimizing the observational strategy of the CLARA2 Antarctic campaign. These measurements will be provided by the Italian Antarctic Meteo-Climatological Observatory. CLARA2 observations will be carried out by ground based active and passive remote sensing instruments operating in the visible, infrared, and microwave spectral regions; as well as by meteorological sensors, and radiosondes. The overall set of instruments will provide a comprehensive data set of atmospheric and cloud parameters.

COMBLE - Cold-air Outbreak in the Marine Boundary Layer Experiment

Bart Geerts
COMBLE (Cold-air Outbreak in the Marine Boundary Layer Experiment) aims to increase the understanding of cold-air outbreaks (CAOs). When cold Arctic air flows from the ice out over the warmer water, strong boundary-layer convection and wind shear interact to form mixed-phase clouds with a highly fetch-dependent structure, first organized in “streets” evolving into cells as the boundary layer deepens. Surface heat fluxes are typically very large, and the cloud and boundary-layer circulation effectively transfers heat into an originally stratified environment. CAOs are also an important factor for the formation of Polar Lows. While often appearing striking in satellite imagery, CAO processes are poorly documented due to their hostile environment. Occurrence and downstream development are not well represented in weather and climate models. The field campaign will be launched in the 2019-2020 timeframe; the main observation period will be in winter: Jan-Apr 2020. COMBLE is built around the ARM Mobile Facility (AMF), observations at Ny-Ålesund and from MOSAiC, tied together by research aircraft. The observation strategy includes a far downstream site (AMF) at the northern Norway coast, a midstream site (ARM instruments plus mobile cloud radar) on Bear Island, and nearstream observations at Ny-Ålesund; upstream observations will come from MOSAiC. Research aircraft will provide in-situ observations and map the spatial development and link the fixed location sites. All fixed sites will provide both surface-based remote sensing of the lower troposphere and in-situ observations such as surface fluxes and radiosoundings. COMBLE modelling will cover scales from the local using LES, regional scales using mesoscale models and the global scale using GCMs.

DACAPO-PESO - Dynamics, Aerosol, Cloud and Precipitation Observations in the Pristine Environment of the Southern Ocean

Patric Seifert
The project Dynamics, Aerosol, Cloud and Precipitation Observations in the Pristine Environment of the Southern Ocean (DACAPO-PESO) is motivated by the need to provide an explanation for the observed evidence of strong regional contrasts in heterogeneous ice formation. Various studies report that heterogeneous ice formation at temperatures between -40 and 0°C is more efficient in the northern hemisphere than in the southern hemisphere. This conclusion was also supported by lidar observations of stratiform clouds in the northern midlatitudes (Leipzig, Germany, 51°C) and the southern midlatitudes (Punta Arenas, Chile, 52° S), conducted by Leibniz Institute for Tropospheric Research (TROPOS), Leipzig, Germany. Meanwhile, the mobile ground-based supersite LACROS of TROPOS is operated to provide observations with co-located lidar, cloud radar, precipitation-profiling radar, Doppler lidar, microwave radiometer, sun photometer, precipitation disdrometer, a radiation balance station, an all-sky cloud camera and irregular launches of radiosondes. These observations allow to derive aerosol-cloud-dynamics-precipitation interaction in much higher detail than with lidar alone. In Europe LACROS has collected multi-year datasets of these observations for the continental site of Leipzig, Germany, and the strongly mineral-dust-burden subtropical region of Cyprus. In a next step, LACROS will be deployed in Punta Arenas, Chile, which is the southernmost point of continental land mass of the southern hemisphere showing a mitlatidudinal to subpolar climate. Contrasting the LACROS observations from Leipzig, Cyprus, and Punta Arenas, which are based on the same instrumentation, will allow to infer the reasons for the regional observed differences in heterogeneous ice formation efficiency.

DACEE - Declining Arctic sea ice cover and its effect on the frequency and severity of weather extremes in Central and Eastern Europe

Maciej Miernecki
In this project, we will focus on the changes in frequency and severity of weather extremes in Central and Eastern Europe induced by the rapid transition in the Arctic environment. Special attention is given to the events with high social and economic impact, such as extreme precipitation events, cold surges and heat waves.

EAIIST - East Antarctic International Ice Sheet Traverse

Joel Savarino
Italian, French, Australian and US scientists unite their knowledge and capability to study the interior of the Antarctic plateau between the French-Italian Concordia station (75°S, 123° E), and the US South Pole station (90°S). The scientific objectives of EAIIST are to study the icy terrain of the Antarctic continent in its driest places. These areas are largely unexplored and unknowns and offer unique and extraordinary morphological characteristics suspected to be analog of glacial conditions. This international consortium of scientists is built around the idea to explore and study by the means of ground vehicles the geophysical (snow physics, surface mass balance SMB, density, temperature, seismicity, etc.), geochemical (impurities, aerosols, air-snow transfer, water isotopes, etc.) and meteorological dimensions (AWS, atmospheric dynamic, air mass transport, etc.) of these most inhospitable and remote place on Earth nevertheless so important for the functioning of the climatic machinery of the Earth's climate.

Exploring the role of sea ice physics in Arctic climate variability and predictability - Exploring the role of sea ice physics in Arctic climate variability and predictability

Daniel Feltham
Including the physics of melt ponds in forced sea ice models has been shown to lead to real seasonal predictability of the Arctic summer sea ice minimum, through the impact of ponds on the albedo feedback mechanism. We shall investigate more advanced models of melt ponds and explore their role in variability and predictability of Arctic sea ice in climate models.

FAMOS - Forum for Arctic Modeling and Observational Synthesis Phase 1 and 2

Andrey Proshutinsky
The Forum for Arctic Ocean Modeling and Observational Synthesis (FAMOS) is an international effort to focus on enhancing collaboration and coordination among arctic marine and sea ice modelers, theoreticians and observationalists based on a set of activities starting from generating hypotheses, to planning research included both observations and modeling, and to finalizing analyses synthesizing major results from the field studies and coordinated numerical experiments. The FAMOS-2 project will be focusing on studies of processes and mechanisms with high and ultra high resolution to improve understanding of physical processes and predictions.

FRAMS - Forecasting Regional Arctic Sea Ice from a Month to Seasons

William Merryfield
This project will advance the science of multi-model sea ice forecasting on time scales of a month to seasons, while developing products and services in association with the establishment of WMO’s Polar Regional Climate Center.

GENICE - Microbial Genomics for Oil Spill Preparedness In Canada’s Arctic Marine Environment

Casey Hubert
Reduced sea ice cover and ice-free summers have led to increases of 166% in shipping through the Northwest Passage since 2004. Increased activity brings increased risks of accidental releases of diesel or bunker fuel and other transportation related contaminants. Furthermore, significant oil reserves are estimated to exist in the Arctic, yet recent decisions by major oil producers signal that drilling in the Canadian Arctic is at least a decade away. This “hiatus” in offshore petroleum exploration and production offers scientists an important window of opportunity to develop emergency preparedness plans, and this opportunity must not be squandered. GENICE will use microbial genomics to generate credible, science-based knowledge on the potential for bioremediation – the biodegradation of oil by naturally occurring microorganisms. Marine microbial communities are nature’s ‘first responders’ in the event of a marine oil spill, yet little is known about this potential mitigation approach in the cold ice-laden Arctic marine environment. The project will achieve key deliverables of (1) new baselines using microbial genomics, (2) bioremediation viability case studies and demonstrations for Arctic marine habitats, and (3) a new approach to dynamic mapping of risks and mitigation potential using microbial genomic biomarkers. These outcomes will interface economic policy development and learning around emergency preparedness and oil spill response in Canada’s Arctic waters. Ongoing engagement and interactive exchange of knowledge between scientists and different end-user groups will include residents of potentially affected northern communities, different levels of government including regulatory agencies, non-governmental and indigenous organizations, and the private sector.

GEO CRI - GEO Cold Regions Initiative: Information Services for Cold Regions

Yubao Qiu
This new Group on Earth Observations initiative, developed from the existing Cold Region task, aims to coordinate global, joint efforts to provide Earth observations and information services to decision-makers over the vast Cold Regions areas, including the North Pole, South Pole, Himalaya-Third Pole and Mountain areas. Contributors include national authorities, universities and international organizations such as ICIMOD, CliC, and SAON, to mention only a few.

H2O-DC - Water Budget Over the DOME C Station

Ricaud Philippe
http://www.cnrm-game-meteo.fr/spip.php?article961&lang=en (HAMSTRAD) and http://lidarmax.altervista.org/lidar/Antarctic%20LIDAR.php (LIDAR)
The aim of the project is to study the water budget over the Dome C (Concordia Station, Antarctica) by means of: 1) an aerosol LIDAR measuring Depolarization and Extinction Coefficient tropospheric vertical profiles, 2) the global Numerical Weather Prediction (NWP) model of Météo-France (ARPEGE) to provide hourly vertical profile of Water Vapour, Cloud Water and Ice Content, Precipitation Fluxes, Temperature, Nebulosity, etc. at Dome C. We will particularly focus on the study of the presence of cloud and diamond dust episodes above the station, and will provide the data collected to the international scientific community.

IABP/IPAB - International Arctic Buoy Programme (IABP) and International Programme for Antarctic Buoys (IPAB)

Ignatius Rigor
The International Arctic Ocean Buoy Program (IABP) was established in 1978 as an international effort to maintain a network of drifting buoys in the Arctic Ocean. The IABP aims to provide meteorological and oceanographic data for real-time operational requirements and research purposes, including support to the World Climate Research Programme (WCRP) and the World Weather Watch (WWW) Programme. Due to the relatively young history of Antarctic buoys, the IPAB was only recently established, but serves basically the same purpose in the Southern Hemisphere.

IAMCO-YOPP - Italian Antarctic Meteo-Climatological Observatory at MZS, Victoria Land and at Concordia

Paolo Grigioni
Systematic meteorological ground observations and radio soundings are performed at Mario Zucchelli Station (MZS) and Victoria Land (VL) since 1987; and at Concordia Station (DC) since 2005. This project aims to continue collecting data for time series, (up to 28 years of data for MZS/VL, up to 10 years for Concordia), for meteo-climatological monitoring of the area, to strengthen scientific data of other projects and for operational activities taking place at the base.

IAS - Intensive Atmospheric Soundings during the Chinese Arctic Cruise in 2018

Dongqi ZHANG
During the "YOPP Special Observing Periods" (July 1st to September 30th, 2018), we plan to launch intensive radiosondes (4 times per day) along the cruise route of Chinese Icebreaker XUELONG in the Arctic Ocean.

ICECAPS - Integrated Characterization of Energy, Clouds, Atmospheric state, and Precipitation at Summit

Matthew Shupe
ICECAPS entails intensive atmospheric measurements at Summit Station, Greenland to operationally characterize properties of the atmosphere, clouds, radiation, and precipitation. Routine measurements include cloud radar, lidar, microwave radiometer, spectral infrared radiometer, precipitation sensor, sodar, and twice daily radiosondes. Coordinated measurements at Summit (provided by other projects) include broadband radiation and surface accumulation. Measurements have been ongoing since May 2010 and are currently funded through August 2018.

IGP - The Iceland - Greenland Seas Project

Ian Renfrew
We will examine wintertime atmosphere-ocean processes in the Iceland and Greenland Seas by characterising its atmospheric forcing and the ocean response by observing the spatial structure and variability of surface flux fields in the region and the weather systems that dictate these fluxes, through the first meteorological field campaign in the Iceland Sea. This will be done as part of a coupled atmosphere-ocean field campaign in winter 2018 – the first such campaign in the subpolar seas – involving a rare wintertime research cruise and a host of ocean observing systems. We will make in situ observations of air-sea interaction processes from several platforms and use these to evaluate meteorological analyses, reanalyses and climate models. We will carry out numerical modelling experiments to investigate the dynamics of selected weather systems which strongly influence the region, but appear not to be well represented in many models; for example, the cold-air outbreaks that stream south over the marginal-ice-zone and densify the surface water resulting in convection; and the orographic jets and wakes that occur downstream of Iceland. We will determine what is required for atmospheric models to produce accurate surface flux fields. We will assess how the Iceland and Greenland Seas are represented in current global and regional climate models and investigate likely changes in the atmospheric circulation and surface fluxes due to climate change. We will use a range of ocean and atmospheric models to establish how current and future ocean circulation pathways function. In short, we will determine the role that atmosphere-ocean processes in the Iceland and Greenland Seas play in creating the dense waters that flow through Denmark Strait and feed the lower limb of the AMOC.

IPSODES - Investigating the predictability of the Southern Ocean dynamics through ensemble simulation hindcasts

Davide Zanchettin
The Southern Ocean (SO) dynamics, and the various fronts of the Antarctic Circumpolar Current in particular, are well known to display a very energetic variability covering a wide range of spatial and temporal scales. Since a substantial fraction of such variability is known to be intrinsic, and therefore basically chaotic, predictability in this part of the world ocean is particularly poor. In this context, the IPSODES project is aimed at improving process understanding concerning the predictability of the SO dynamics through ensemble simulation (ES) hindcasts analyzed by means of various statistical techniques supported by dynamical interpretations, with special focus on multiscale interactions linking high-frequency (up to seasonal) and low-frequency (interannual and larger) variability. Existing state-of-the-art eddy-permitting global ocean-sea-ice model ESs and coupled global atmosphere-ocean-sea-ice model ESs developed for decadal climate predictions will be used. Moreover, new ESs performed with a regional ocean model specifically developed for this project will also be carried out: sensitivity numerical experiments to assess model uncertainty will be performed with these new simulations. By improving our understanding of the predictability properties of oceanic variability, IPSODES will contribute toward more reliable predictions of the SO dynamics, on both the high- and low-frequency. This will in turn (i) contribute to enhance ocean modelling systems in the framework of the GIPPS, (ii) suggest improvements to the oceanic observational system, and (iii) provide further knowledge in support of coordinated research on subseasonal to seasonal (WCRP-S2S initiative) and decadal climate predictability and predictions (CMIP6-DCPP initiative).

JANUS - Joint Arctic research on New and Unusual States

Jun Inoue
The JANUS project is a Japanese joint research project to understand the uncertainty of the state of the `New Arctic’. JANUS focuses on the water cycle in the Arctic in particular. To understand the conditions of the new and unusual Arctic, the effects of snow/rain on sea ice, precipitation systems including clouds and aerosols over the land and ocean, and their impact on the oceanic structure will be investigated by both observations and numerical models. A challenging goal of the JANUS project is to understand an impact of latent heat release from condensation in the Arctic on atmospheric circulations in the mid-latitude through a development of a global non-hydrostatic cloud resolving model tuned for the `New Arctic’. This provides new insight into understanding the linkage between the Arctic climate change and mid-latitude extreme weather events. JANUS research activities consist of (1) enhancing the observation network based at Ny-Alesund and the Japanese research vessel (RV) Mirai, (2) participating in the MOSAiC drift, (3) modeling efforts by using a data assimilation system and cloud resolving models, and (4) archiving the aforementioned data. The year-round field program with RV Polarstern and the related distributed observing network will provide a comprehensive data set, improving our cloud resolving models and providing us a chance to participate in the regional model intercomparison project (Arctic CORDEX).

JAWS - Justified Automated Weather Station Software

Charlie Zender
JAWS is a scientific software workflow to ingest Level 2 (L2) data in the multiple formats now distributed, harmonize it into a common format, and deliver value-added Level 3 (L3) output suitable for distribution by the network operator, analysis by the researcher, and curation by the data center. NASA has funded JAWS (project summary) from 2017/10/01–2019/09/30. Automated Weather Station (AWS) and AWS-like networks are the primary source of surface-level meteorological data in remote polar regions. These networks have developed organically and independently, and deliver data to researchers in idiosyncratic ASCII formats that hinder automated processing and intercomparison among networks. Moreover, station tilt causes significant biases in polar AWS measurements of radiation and wind direction. Researchers, network operators, and data centers would benefit from AWS-like data in a common format, amenable to automated analysis, and adjusted for known biases. The immediate target recipient elements are polar AWS network managers, users, and data distributors. L2 borehole data suffers from similar interoperability issues, as does non-polar AWS data. Hence our L3 format will be extensible to global AWS and permafrost networks. JAWS will increase in-situ data accessibility and utility, and enable new derived products.

KOPRI-SH - Investigation for the Cause of East-West Different Climate Responses in Antarctica

Tae-Jin CHOI and Seong-Joong KIM
This project is funded by KOPRI for the period 2017-2019 with the goal of understanding the role of atmospheric processes in the east-west climate differences in Antarctica. The three main research themes are: 1) sensitivity of Antarctic climate to a change in external forcing; 2) atmospheric processes in the Pacific sector of Antarctica through in-situ observation and synoptic scale numerical simulations; and 3) the relationship between biogenic dimethylsufide (DMS) and aerosol particle formation in the Antarctic atmosphere.

KPOPS - The Korea Polar Prediction System for Climate Change and Weather Disaster

PI: Baek-Min Kim, YOPP contact point: Joo-Hong Kim
KPOPS is a 4-year project funded by the Korea Polar Research Institute (KOPRI) that aims to achieve predictability of Arctic-midlatitude climate change and weather disasters by enhancing Arctic atmospheric observations and by improving climate/weather forecast models. KPOPS is also a name of the models to be developed, which includes both the global climate model (KPOPS-Climate) and the weather forecast model (KPOPS-Weather).

LAVA - Long-term Aerosol Variations in Antarctica: a challenge for climate change

Giampietro Casasanta
Antarctica is a favourite observatory to investigate environmental modifications and climate change. Atmospheric aerosols play a key role in Earth radiative balance, and their response to climate change may constitute a relevant feedback loop (IPCC 2013). Despite their importance, there are no studies analysing observations of Antarctic aerosols properties all over the continent by different simultaneous techniques. Through a vast network of instruments and international collaborations, LAVA aims to investigate Antarctic aerosol properties variations since the last decade along the whole continent, to understand if there are changes attributable to natural variations and quantify the impact of climate change. Continuous remote sensing measurements of aerosol properties in summer will be provided by both the sun-sky radiometers deployed at the British Antarctic Survey and at the Japanese National Institute of Polar Research stations (part of the ESR/SKYNET network), as well as by the AERONET radiometers located all over the continent. To improve the existent network and get a better characterization of the Ross Sea area, a sky radiometer and a ceilometer will be deployed at Mario Zucchelli Station. Aerosol vertical profile all over the stations will be estimated by ground-based lidars and satellite measurements, and air masses back trajectories will be used to clarify if the observed variations are due to atmospheric transport or changes in local meteorological parameters. All the collected data and deliverables will be stored and organized in an integrated, publicly available on-line database, while the results will be published and disseminated through a dedicated educational and outreach program.

MACSSIMIZE - Measurements of Arctic Clouds, Snow, and Sea Ice nearby the Marginal Ice ZonE

Chawn Harlow
MACSSIMIZE is a planned measurement campaign to be carried out by the Met Office during Feb/Mar 2018 as part of YOPP. There is an associated plan for data analysis from the campaign including model evaluation and development. In addition, the Met Office hopes to run models throughout the YOPP Core Phase including the operational NWP suite, a regional high resolution model, a seasonal forecasting model with coupled ocean and atmospheric components, and an experimental coupled ocean-atmospheric NWP system as well as the HadGEM3 coupled climate model. The MACSSIMIZE field campaign is currently planned to take place in two locations: Fairbanks, AK and St. John’s or Goose Bay, NL. The Fairbanks campaign will target (1) snow emissivity measurements at IR and mm-wavelengths over collocated ground-based measurements of snow structure on sea ice and nearby land, (2) boundary layer and energy balance measurements in clear and cloudy skies, and (3) orographic flows and their leeside impacts. The Labrador campaign will primarily target cold-air outbreak conditions over the Labrador Sea but opportunities to make the other measurements listed above may arise. The goal of these measurements and modelling efforts is to improve predictability in the Arctic while focussing on (1) assimilation of satellite sounder data into NWP systems, (2) evaluating and developing boundary layer and snow pack parameterizations suitable for Arctic conditions for use in coupled ocean-atmosphere NWP and climate models, and (3) studies of a specific Arctic-mid-latitude exchange mechanism (cold-air outbreaks) that is difficult to model within current weather forecasting models.

MARCUS - Measurements of Aerosols Radiation and CloUds over the Southern Oceans

Greg McFarquhar
The strong seasonality in aerosol sources and sinks over the Southern Ocean (SO) is poorly understood. Weather and climate models, challenged by uncertainties in simulating SO clouds, aerosols, and precipitation, require improved understanding of these processes and of cloud feedbacks in response to warming. Models underestimate reflected solar radiation, particularly in cold sectors of cyclonic storms, due to difficulties in representing pervasive supercooled and mixed‐phase boundary layer clouds. The Measurements of Aerosols Radiation and CloUds over the Southern Oceans (MARCUS) experiment will acquire observations between 9/17 and 4/18 using the Department of Energy Atmospheric Radiation Measurement (ARM) Program’s Mobile Facility‐2 (AMF2) on the Australia Antarctic Division Aurora Australis as it makes routine transits between Hobart and Mawson, Davis and Casey and Macquarie Island. Measurements of cloud condensation nuclei (CCN), thermodynamics, cloud and radiative properties will be obtained by radiosondes, micropulse lidar, microwave radiometer, stabilized marine W‐band (95 GHz) cloud radar, Vaisala Ceilometer, Inertial Navigation System sun photometer, and downwelling radiometers. User‐supplied filter samples will be collected and processed to determine immersion freezing ice nucleating particle (INP) concentrations as a function of temperature. Data in cold waters poleward of 60°S where supercooled water in cold sectors of cyclones are frequent, will document how temperature‐dependent distributions of cloud properties and frequency of supercooled water vary with CCN, INPs, synoptic regime, latitude and season. Parameterization development and testing are integrated in the design so that systematic confrontation and improvement of models with data is possible.

MIDO - Multidisciplinary Ice-based Distributed Observatory

Benjamin Rabe
The aim of MIDO is to deploy several multi-disciplinary buoy arrays in the ice-covered oceans of both hemispheres between 2017 and 2020. The core of this project is the continuous monitoring of several key parameters across the atmosphere-snow-sea ice-ocean interfaces, linking physical and biogeochemical processes. (Update: only northern hemisphere)

MOSAiC - The Multidisciplinary drifting Observatory for the Study of Arctic Climate

Matthew Shupe
MOSAiC will be focused on obtaining a full year of coupled atmosphere, ice, ocean, and ecosystem measurements from a drifting station in the central Arctic sea ice.

OAPASI - Observation, Analysis and Prediction of Arctic Sea Ice: Oceanographic and Cultural Perspectives

Dan Kelley
Sea ice is a major feature of Canadian waters, with important economic, environmental and cultural effects. There is clear evidence of change in northern-hemisphere ice cover, but the fundamental causes are uncertain, which greatly limits the reliability of predictions of the future. The ice-related parameterizations in today's numerical models are not as well established as other model components, partly because of the inherent complexity of convective and turbulent processes, and partly because of the lack of observations to constrain the parameterizations. Theme 1 of this project starts with the analysis of a unique dataset collected in the Barrow Strait, using a profiling system called the Icycler. This enables water-profile measurements very near to the ice, providing key dynamical insights that are unobtainable with conventional instruments or visual monitoring of ice cover. The resultant data will enable better operational predictions of ice variation. Put into a theoretical context, the data may pave the way for needed refinements in model parameterizations. Theme 2 builds on the excellent work that has already been conducted with respect to Arctic sea ice from both a natural scientific and social scientific perspective. After extensively reviewing and distilling knowledge gleaned from indigenous and scientifically-based sea-ice studies (including those of Theme 1), the goal is to make this information accessible to a population that is farther removed from the environmental immediacy of the situation. Specifically, it will create a framework wherein school-aged children can learn about the importance of sea ice, and of different ways of knowing and understanding the natural world.

OASIS-YOPP - Observations of the Arctic Stratosphere In Support of YOPP

Giovanni Muscari
Polar stratospheric processes impact tropospheric circulation, climate, and weather patterns. One of the most important processes occurring in the stratosphere is the springtime final breakdown of the stratospheric polar vortices (Stratospheric Final Warming, SFW). In the Arctic, SFWs may follow two different patterns: they can start at around 10 hPa and then proceed upward and downward, or start in the lower mesosphere and progress downward with time. These two paths lead to different tropospheric pressure and temperature patterns in the following month. Both the timing and the vertical profile of Arctic SFWs can therefore be employed as predictive tools and verification parameters. This project aims at contributing to two of the main PPP research goals: 1) Implement additional observations in the polar regions and 2) Establish and apply verification methods for modeling efforts in polar regions. We will provide daily ground-based and in situ measurements of lower and middle atmospheric chemical and physical parameters during the period of occurrence of SFWs in the Arctic, February 1st to March 31st, 2018 (during SOP). Measurements of stratospheric vertical profiles of N2O, H2O, CO, O3, temperature and pressure, and daily launches of radio soundings will be carried out from Thule (76.5°N, 68.8°W), Greenland, in a region where conventional observations supporting YOPP appear to be very scarce. These data sets will provide highly resolved measurements, from the lower stratosphere to the mesosphere, of a SFW in the Arctic and will be used to verify CCMs prediction of the timing and the vertical profile of SFWs.

PAIOArC - Processes governing Atmosphere-Ice-Ocean interaction in a changing Arctic Climate

Gunnar Spreen
Interactions in the Arctic atmosphere-sea-ice-ocean system change the circulation/dynamics/heat in the ocean and lower atmosphere, and the thickness/distribution of sea-ice and snow. Autonomous, integrated atmosphere-ice-ocean buoy systems have been developed to provide year-round observations from the harsh-and-hard to access Arctic Ocean. In addition to giving a quasi-synoptic view on regional scales, these systems allow an in-depth study of local processes. Satellite observations allow additional synoptic insight and need to connect observational scales. Building on our expertise, we propose to study key local processes involving sea-ice-atmosphere-ocean. In addition to synthesising existing autonomous observations and satellite data products in scientific analyses, the work will feedback with buoy-related programmes and participate in the upcoming international drift campaign MOSAiC. This project will support YOPP by evaluation of near-real-time observational systems in a long-term context.

PARCS-Climate - PARCS (Pollution in the Arctic System)-Climate

Kathy Law
PARCS-Climate aims to improve the quantification of aerosol and cloud interactions in the Arctic and hence enhance predictive capability of climate change in the Arctic at local and regional scales as well as at global scales. We plan to combine ground-based, airborne and satellite observations with microphysical, regional and global climate modelling to improve our knowledge about Arctic mixed-phase clouds and interactions with local and remote sources of anthropogenic aerosols. New field campaigns are planned for 2018 in northern Scandinavia and Svalbard. The project involves groups from France, Norway and Sweden as well as international collaborators (e.g. USA, Japan, Korea).

PDMS - Polar Data Management Service

Angelo Corallo
Since 2016, 10 or more PNRA projects have received YOPP endorsement. Several of them have been funded and are planning to carry out field activities during the YOPP-SH Special Observing Period (SOP). Most projects do not have specific resources to assure data management and flow into the YOPP Data Portal. Moreover, large differences of projects exist in terms of specific competencies and IT infrastructure. Also, a large uncertainty exists on the amount of observations Italian projects will be able to provide to the YOPP Data Portal. This proposal aims to secure the Italian contribution to YOPP, providing (i) high-level competencies and services to involved projects, and (ii) an efficient and competent front end to YOPP. For research projects, before and during SOP, a data-mining action will be activated to increase the data flow from field activities to YOPP. On the side of the YOPP Data Portal, a technological and multi-purpose infrastructure, named Polar Data Management Service (PDMS), will be created to collect, store, group and harmonize in format all datasets relevant for YOPP, as recovered by endorsed Italian projects. PMDS will provide the appropriate IT level to share data efficiently. In particular, for specific measurements, PDMS will able to collect daily data from Terra Nova Bay and transmit them to the YOPP Data Portal. During the YOPP Consolidation Phase, PDMS will be further developed in such a way to improve the challenging issues of data collection from projects, supporting scientists through simple and intuitive interfaces and a customized working environment. This activity will allow to maximize the Italian contribution to the YOPP Data Portal, recovering all possible information arising from PNRA projects, even if not endorsed by YOPP.

PFRECaN - Predicting the Future(s) of Renewable Energy in Canada's North

Adam Monahan
The proposed research has three key objectives: (1) assessment and development of regional climate modelling capacity for the Canadian Arctic, with an emphasis on improving boundary layer process representation in numerical models; (2) assessment of wind and solar energy resources in the Canadian Arctic over the next 20-50 years, with a focus on natural variability and anthropogenically forced change; and (3) an engineering/economic assessment of the integration of renewables into electricity generation in communities in the Canadian Arctic, taking into account projected changes. This research program involves partnerships and multidisciplinary interactions among Hydro Quebec, the World Wildlife Fund, climate modellers, field-based atmospheric observationalists, and engineers. We have also reached out to the community of Sachs Harbour and the Government of the Northwest Territories.

POPEYE - Profiling at Oliktok Point to Enhance YOPP Experiments

Gijs de Boer
POPEYE involves enhanced profiling of the atmosphere at Oliktok Point, Alaska during the second YOPP Special Observing Period (7/1/18-9/30/18). Included in this activity is an increase in the number of radiosondes launched (4x daily), and profiling of the lowest 1000 m of the atmosphere using tethered balloons and unmanned aircraft systems (UAS). These activities will collect information on the vertical structure of thermodynamic properties, winds, and aerosol properties.

PORA-IP - Polar Ocean Reanalysis Intercomparison Project

Petteri Uotila
Ocean reanalysis (ORA) combines observations either statistically or with a hydrodynamical model, to reconstruct historical changes in the ocean. Global and regional ORA products are increasingly used in the polar research, but their quality remains to be systematically assessed. To address this, the Polar ORA Intercomparison Project (PORA-IP) has been established following on from the ORA-IP project (Balmaseda et al. 2015 with other papers in a special issue of Climate Dynamics). Currently, the PORA-IP team consists of 20 researchers from 13 institutes and universities. The ORA-IP products with polar physics, such as sea ice, have been collected in a public database. In addition to model output, available observational polar climatologies are collected and used in the assessments. Due to the extensive variety of products, this database can be expected to become a valuable resource also outside the PORA-IP community. For a comprehensive evaluation of ORAs in the Arctic Ocean and the Southern Ocean several specific diagnostics are needed. The collection of PORA-IP diagnostics targets the following topics: hydrography; heat, salinity and freshwater content; ocean transports and currents; mixed layer depth; and sea-ice concentration and thickness. Based on these diagnostics, ORA mutual spread and biases against observations will be quantified, and reasons for discrepancies will be discussed. PORA-IP diagnostics results, to be published in peer reviewed journals, will provide closely related information for those interested in enhancing model predictive skill over a range of time scales including seasonal to decadal. These expected outcomes link the PORA-IP effort to YOPP.

QSIWO - The Qaanaaq sea ice winter observatory

Steffen M. Olsen
Objective: To establish a winter observatory on the fjord ice in Inglefield Fjord, NW Greenland, December 2017 to June 2018, in part as a direct contribution to the Year of Polar Prediction (YOPP) including the first coordinated Special Observing Period of intensified observations across the Arctic in winter 2017/2018. Applications of data include sea-ice and snow processes, calibration and verification of satellite remote sensed data products, fjord circulation, stratification and mixing, ocean-glacier interactions, local or fjord scale meteorology and model verification.

RadiCA - Radiation Fluxes and Cloud Features from Surface-Based Observations in the Antarctic Peninsula and Weddell Sea Region

Vito Vitale
The main goal of our proposal is to characterize the surface radiative budget as well as cloudiness which features at the Argentine Bases Marambio and Belgrano II during the YOPP-SH Special Observing Period (SOP) as well as the YOPP Consolidation Phase. Specific objectives to secure our main goal during the SOP will be: 1 - develop a compact Radiation Measurement UNIT (RMU) robust enough to allow continuous measurements in harsh environment through which to make shortwave, longwave observations as well as to record status of the sky. 2 - secure UV measurements at both stations. 3 - develop specific tools to analyse on a daily basis (weakly for clouds) collected data and extract parameters of interest. For radiation these will include QA/QC SW and LW downwelling and upwelling fluxes, diffuse and direct components of solar radiation, UV spectral flux and doses. For clouds these will include, on a continuous base, cloud fraction derived both from radiometric measurement and sky camera observations, cloud type and cloud effect on SW radiation. In addition cloud base (or cloud ceiling) will be obtained by routine observations performed at the two stations. From UV measurements columnar ozone content will be also derived. Moving forward to YOPP consolidation phase, we plan to: 1 - extend dataset and its analysis, start to collect information on seasonal and inter-annual variability, determine Cloud radiative Forcing (CRF) 2 - perform extensive comparison between automatic and visual cloudiness observation methods. They being very useful to better understand quality and value of historical datasets at the two stations 3 - make comparison with cloudiness regime of Ross Sea and Antarctic Plateau. Make similar comparison for UV fluxes in the Peninsula and at Concordia.

RASP - Towards a Reliable Arctic Sea ice Prediction using ensemble-based multivariate data assimilation

Jiping Liu
This project aims to advance understanding of different assimilation methods for sea-ice forecast initialization, improve coupled prediction systems and the data assimilation capability of newly developed satellite datasets, and enhance predictability and prediction of Arctic sea ice through the collaboration between Chinese and German scientists. The following targeted activities provide a framework for the project: The coupled prediction systems of the Chinese partners will be augmented by assimilating satellite-retrieved sea-ice parameters developed by the German partners (including sea-ice concentration, ice types, sea-ice thickness, and melt pond fraction) with an ensemble-based Kalman filter (LESTKF). To assimilate melt ponds, the coupled prediction systems of the Chinese partners will be extended to include a prognostic melt pond parameterization. Additionally, sea-surface temperature and sea level anomaly data will be assimilated to constrain the state of the ocean. More importantly, the impact of observational errors of the assimilated sea-ice parameters on Arctic sea-ice prediction will be assessed. As sea-ice thickness distribution is not Gaussian, and sea-ice dynamics are nonlinear, new non-linear data assimilation methods will be developed and implemented in the coupled prediction systems of the Chinese partners, and their assimilation impacts on Arctic sea-ice prediction will be studied and compared with the linear-based LESTKF. Finally, the predictability of Arctic sea ice and its relationship with the representation of the internal variability in the coupled prediction systems will be investigated.

REDOCCA - Regional High-Resolution Downscaling of Climate Change in the Antarctic

Günther Heinemann, Tido Semmler, Ralph Timmermann
The goal of the project is the improved understanding of atmosphere-ocean-ice interactions and their impact on ocean circulations in the Weddell Sea region by simulations using a high-resolution atmospheric model, which drives a sea-ice ocean model. For the recent climate, we perform simulations for the period 2002-2019 with resolutions of 5-15 km for the atmosphere (1 km for case studies) and down to 3 km for sea ice and the ocean. For the future climate end of the 21st century, we will perform dynamical downscaling of CMIP6 runs with 15 km/3 km (atmosphere/ocean).

RSR-Mesocyclones - The offshore air mass journey and interaction with the Ross Sea surfaces: A process-based investigation of regional climate influenced by mesocyclones

Marwan Katurji
The coastal areas of Antarctica have been at the forefront of disruption due to climate change. Understanding mechanisms that cause regional climate change are therefore vital in assessing coastal impacts. We aim to understand regional climate and meteorological variability in the near-shore environment. To do that we need to know the consequences of interaction between the constant outflow of the continental air masses which drain through steep tributary valleys in the Trans-Antarctic mountains, and then travel over the Ross Sea ice/water and interact with the moist oceanic atmospheric pressure systems that influence much of the Southern Hemisphere’s weather. Our research will use two methods for studying the regional climate of Ross Sea Region (RSR); (1) The Antarctic Mesoscale Prediction System (AMPS), which is an operational weather forecasting system customized for the Antarctic environment. AMPS will simulate case study events and provide seasonal climatology at 3-km resolution, and (2) height controlled free-floating meteorological balloons will be deployed from Terra Nova Bay to map atmospheric variables at a regional scale (where the continental air mass interfaces with the synoptic scale weather systems along the path of varying sea ice/water extents) for analysis and model evaluation. The outcome of this research will be a better understanding of surface-atmospheric mechanisms that contribute significantly to temperature and precipitation variability in the Ross Sea Region. This outcome will then transfer to a better understanding of the variability of the sea ice extent, and continental snow and ice mass balance.

SALIENSEAS - Enhancing the Saliency of Climate Services for marine mobility sectors in European Arctic Seas

Machiel Lamers
The rapid warming in the Arctic Ocean environment has profound socio-economic consequences, which generates a strong call from local communities and various marine sectors for more user-specified climate services. Currently, there is limited availability of, and accessibility to, high-quality Arctic climate information for operational and strategic decision making. The SALIENSEAS project will co-develop, in a team of social and natural scientists, met-ocean service personnel, and end-users, climate Arctic forecast products tailored to key social, environmental and economic needs. In the project, Arctic sub-seasonal and seasonal prediction capabilities and climate projections in the Arctic will be systematically exploited, in order to establish baseline expectations for predictive power and to guide advances in predictive capability. Based on a thorough understanding of the current uptake and need for climate services in several mobile Arctic Ocean end-user groups, a range of demonstration services will be co-defined and co-produced with these stakeholders. During the project period we will conduct in-depth social science research in relevant end-user practices, disseminate forecast products to end-users of climate information, and develop a more participatory, flexible and tailored approach to developing forecast products. The SALIENSEAS project brings together a strong consortium of international research institutes, whereby high-level experts on Arctic socio-economic sectors and governance processes, weather and climate prediction, and data dissemination will work in line with stakeholder representatives. The developed tailored forecast products will be merged into Norway’s and Denmark’s met-ocean and sea-ice forecasting infrastructures.

SAMEECA - Surface-Atmosphere Mass and Energy Exchanges at a Coastal Antarctic site

Mauro Mazzola
sphere mass and energy exchanges in coastal Antarctic thanks continuous measurement of a large set of parameters and development of multiscale modelling. Field activities will be carried out year-round at the Korean Jang Bogo (JBG) Antarctic Research Station, located at the coast of Terra Nova Bay, in the vicinity of the Italian Mario Zucchelli Station (MZS). Measurement and analysis of radiation components, atmospheric constituents and energy fluxes, meteorological and micrometeorological parameters, will be implemented jointly by KOPRI, CNR and UniFI, in a way similar to the collaboration already active in the Arctic region at Ny-Ålesund (Svalbard). Measurements will be implemented in such a way to allow Terra Nova Hub (including both MZS and JBG) could became the first WMO-GAW regional station in the Ross Sea area. This will represent an important legacy, contributing to GCOS and WMO programs related to radiation regime and atmospheric composition.

ScIMiTaR - forecasting summer Sea Ice MelT from winter ice surface Roughness

Jack Landy
Our capacity to forecast seasonal changes in sea ice cover, predict weather patterns and pursue responsible trans-polar shipping, during the High Arctic summer, will hinge on our understanding of sea ice melt processes. This project aims to exploit the influence of sea ice surface topography on the formation of meltwater ponds at the ice surface in summer, which regulate the sea ice albedo, to improve seasonal forecasts of ice melting rates and breakup timing. To achieve this, we will develop new techniques for measuring the sea ice surface roughness in winter from multiple sources of satellite data, including altimetry (Cryostat-2. , AltiKa etc.) and MISR, over the period from 2000-present. These measurements will be used to develop a unifying relationship between the sea ice surface roughness and ice thickness distribution at relevant scales for numerical sea ice modelling. Roughness observations will then be assimilated into the CICE (Los Alamos sea ice model): Los Alamos sea ice model to develop a forecasting methodology for robustly predicting summer sea ice parameters (albedo, breakup timing), at lead times >6 months, based on the state of the winter sea ice cover. We intend to examine whether decadal changes in sea ice roughness may have enhanced Arctic climate warming through amplification of the ice-albedo feedback mechanism. Finally, we aim to provide probabilistic forecasts of the ice melt parameters to the academic community and public/private sectors through the Sea Ice Prediction Network (SIPN).

SIPN South - SIPN South: Coordinating Seasonal Predictions of Sea Ice in the Southern Ocean for 2017-2019

François Massonnet
Like many regions of our planet, the Antarctic is currently undergoing profound environmental changes. Not all of these changes are well understood, partly due to a lack of comprehensive observational datasets describing this region. The Antarctic is one of the most under-sampled places on Earth, well behind the already sparsely monitored Arctic. Floating at the interface between a hostile atmosphere and a highly dynamic and weakly stratified ocean, sea ice is a major element of the Antarctic climate. Sea ice is also a major obstacle for vessels operating in the Antarctic coastal region. Compared to the Arctic, there is a key scientific gap in understanding to what extent the seasonal development of austral sea-ice cover is predictable, what the sources of this predictability are and whether it is possible at all to extract any useful information for stakeholders from these predictions. Inspired by the Sea Ice Prediction Network, SIPN South has the ambition to explore the initial potential (or lack thereof) of current sea ice prediction systems in Antarctica. The end-objective of this two-year project is to coordinate a real-time exercise of regional forecasting of austral summer sea ice conditions coincident with the YOPP Special Observing Period of early 2019. Forecasts will be analysed retrospectively to determine if they can be utilized to support decision-making for the logistics of observational field campaigns or touristic expeditions, that are expected to boom in the next decade. SIPN South, beyond the assessment of seasonal sea ice predictability in the Southern Ocean, has also the ambition to become a new hub around which the polar prediction community can discuss selected topics related to Antarctic sea ice in general.

SIPN2 - Sea Ice Prediction Network Phase 2

Julienne Stroeve
TA key finding that emerged from the Sea Ice Prediction Network (SIPN) is that predictions tend to have reduced skill in extreme years, away from the trend line. The objective of the proposed research under Phase 2 of SIPN (SIPN2) is to reduce these biases through a multi-disciplinary approach that includes models, new products, data analysis, scientific networks, and stakeholder engagement. More specifically, the team will: (1) Investigate the sensitivity of subseasonal-to-seasonal sea ice predictability in the Alaska Sector to variations in oceanic heat and large-scale atmospheric forcing using a dynamical model (NCAR CESM) and statistical forecasting tools, focusing on spatial fields in addition to total extent summaries; (2) Sea Ice Outlook (SIO) submissions will be assessed for accuracy based on methodology and initialization; (3) Develop new observation-based products crucial for improving sea ice predictions, including sea ice thickness, surface roughness, melt ponds, and snow depth; (4) Stakeholder Research and Engagement: evaluate socio-economic value of sea ice forecasts to stakeholders who manage ship traffic and coastal village resupply in the Alaska Sector, and engage the public in Arctic climate and sea ice prediction through blog exchanges, accessible SIO reports, bi-monthly webinars, and by making public data sources useful to non-scientists and scientists alike; and (5) Evolve network generated Sea Ice Outlook forecasts and reporting for September minima will continue as in SIPN. SIPN2 forecasts will be expanded to include full spatial resolution and emerging ice-anomaly-relevant months (October/November).

SIRT - Sea Ice Research Team: New Observation Platforms in High Latitudes

Lauren Farmer
Since 2015, Lauren Farmer and Alex Cowan have collected sea ice data while employed as photographer and geologist on Russian icebreaker "50 Let Pobedy", chartered in the summer season by tour operator Poseidon Expeditions. With prior and ongoing training, and the support of their advisors, they endeavor to collect sea ice data such as extent, thickness, age and degree of melt during repeat transects from Franz Josef Land to the geographic North Pole. In June/July of 2017, these visual observations will be paired with meteorological recordings timed to satellite overpasses and in coordination with NASA’s GLOBE Observer program. Lauren and Alex will also record melt pond salinity and depth profiles at an ice station at the pole and gather aerial video and photos of the pack ice during helicopter flights. With this extended access to the eastern Arctic Ocean during the early stages of the summer melt season and following a relatively unusual repeat transect itinerary, they look forward to contributing to YOPP and collaborating with interested partners. Additionally, they are open to discussing further projects during this planned period of observing, such as the deployment of buoys and weather balloons.

SnowCast - Snow Contrasts Controlling the Fate of Sea Ice

Stefanie Arndt
The overall aim of the project SnowCast is to locate and quantify internal snowmelt, snow metamorphism, and snow-ice formation in the Antarctic snowpack on different spatial scales. Doing so, results will improve our understanding on processes and interactions in the snowpack as well as at the snow/ice interface associated with seasonal and inter-annual variations in the sea-ice mass budget of the Southern Ocean. In order to achieve this aim, in-situ observations of the Antarctic snow cover will be combined with a 1-D snow model (SNTHERM) to describe the temporal evolution of small-scale processes in the snowpack. Available remote sensing data will be utilized to quantify the mentioned variables on larger scales.

SOCRATES - Southern Ocean Clouds Radiation Aerosol Transport Experimental Study

Greg McFarquhar
The goal of SOCRATES is to improve our understanding of clouds, aerosols, radiation, precipitation, air-sea exchanges and their interactions over the Southern Ocean (SO) through collection of a set of focused observations over the SO, that will be coordinated with process and large scale modeling spanning a variety of temporal and spatial scales. The observations include both fine-resolution intensive observations from airborne and shipborne platforms and longer timescale observations that capture the seasonal cycle.

SWIANT - Ship-based Wind Lidar Measurements of the Antarctic Boundary Layer

Günther Heinemann
The group of the University of Trier will perform measurements of vertical and horizontal profiles of wind, turbulence and aerosols. We will use a wind lidar, which is a programmable scanner and can operate with a maximum range of 10 km. The wind lidar will be operated in the eastern and southern Weddell Sea during a cruise PS111 of R/V Polarstern (18 January – 14 March 2018). Radiosondes launched from R/V Polarstern will be used for comparisons of the wind profiles. The data will be used for the verification of simulations using a high-resolution regional climate model and for process studies.

SWIARC - Ship-based wind lidar measurements of the Arctic boundary layer

Günther Heinemann
The group of the University of Trier, Germany, will perform measurements of vertical and horizontal profiles of wind, turbulence and aerosols. We will use a wind lidar, which is a programmable scanner and can operate with a maximum range of 10 km. The wind lidar is operated in the Arctic during two cruises of R/V Polarstern: PS106 around Svalbard (24 May–24 July 2017) and PS109 in the Fram Strait and at the east Greenland coast (12 September–14 October 2017). Radiosondes launched from Polarstern will be used for comparisons of the wind profiles. The data will be used for the verification of simulations using a high-resolution regional climate model and for process studies.

The Nansen LEGACY

Marit Reigstad
The Nansen LEGACY project explore the integrated nature of environment, climate and ecosystem. The living Barents Sea is evolving under external constraints of physical forcing, and direct and indirect human impacts. The consequent management of the region and resources should be informed by, and based on the past, present and future. The new Norwegian ice-breaker Kronprins Haakon will be a core facility. The team reflects the complementary scientific and logistic capabilities of the eight participating governmental institutions committed to Arctic research, and to the Barents Sea region in particular. Recruitment of a new generation of polar researchers equipped with interdisciplinary knowledge and emerging tools is an important task. The Vision: LEGACY will establish a novel and holistic Arctic research platform and provide the integrated scientific knowledge base required for the sustainable management of the environment and marine resources of the Barents Sea and adjacent Arctic Basin through the 21st century.

TICFIRE - Thin Ice Clouds in Far IR Experiment for Microphysics and Atmospheric Water Cycle in the Arctic

Jean-Pierre Blanchet
Optically Thin Ice Clouds (TIC) processes are still poorly represented in data assimilation and in atmospheric models. It is now recognized that anthropogenic aerosol can alter cloud microphysics and precipitation. In addition to the needs of filling a gap in cloud observation at high latitudes, these clouds, sensitive to aerosols via ice nucleation, can significantly modulate the amount of far infrared radiation escaping the Earth, and consequently the temperatures in the upper and the mid troposphere. Since their signature in the far infrared is also very sensitive to their microphysical properties (crystals size and shape) and optical depth, these quantities can be retrieved from ground-based and satellite observations. Theoretical calculations and measurements demonstrate that the far infrared spectrum of the atmosphere could provide valuable information for weather forecast data assimilation and climate simulations, about its water vapour content, the microphysical characteristics of ice clouds and common light precipitation, especially in dry and cold regions. In this context, the Thin Ice Clouds in the Far InfraRed Experiment (TICFIRE) tech demo satellite mission was proposed to the Canadian Space Agency and is currently under review. In view of YOPP, with the Canadian Space Agency and in collaboration with NETCARE, PAHA and AVATAR, we have initiated new measurements in the mid and far IR range (8-50 µm) to advance our knowledge of the water cycle in the high Arctic with the deployment of the Far IR Radiometer (FIRR). The FIRR is meant to be a breadboard for the future TICFIRE satellite instrument and for new ground-based measurements with potential applications to Canadian Arctic stations for improving monitoring and weather prediction in polar regions.

TRIMMER - TRaceability and Improvement of Meteorological Measurements during YOPP intEnsive peRiods, to better investigate ABL characteristics and coupling processes in coastal Antarctica.

Vito Vitale
"Cover an extended period of coordinated intensive observational and modelling activities.." is a core element of YOPP (Year of Polar Prediction) implementation plan, fundamental to fulfill the mission to improve our environmental prediction capabilities in both polar regions on a wide range of time scales. Present proposal, through cooperation between atmospheric and metrology communities aims to assure such activities in the coastal region of the Ross Sea during the intensive YOPP observing periods. Starting from the consolidated data set collected thanks a large international cooperation, multiscale modelling activities devoted to deepen knowledge on ABL features in coastal Antarctica and coupling processes at and near the surface.

TWASE - Towards better tailored weather and marine forecasts in the Arctic to serve sustainable economic activities and infrastructure

Timo Vihma
In the Arctic, economic activities, such as navigation, aviation, mining and energy production, are extremely sensitive to weather. More human activities in the Arctic will induce many new needs for operational weather and marine services (WMS). To address these needs, TWASE will build a close, interactive collaboration between meteorologists and economists. The main objectives of TWASE are to A. Identify, classify, prioritise and conceptualise the user needs of WMS for developing sustainable economic activities in the Arctic B. Improve the predictability of Arctic weather and sea ice conditions and their effects on navigation, aviation, and wind energy production C. Evaluate and optimize, together with the end-users, the benefits of the improved WMS. To meet Objective A, we will • create a set of combined climate change – socioeconomic scenarios for the Arctic; • engage stakeholders in the development process of WMS and assessment of their benefits. To meet Objective B, we will • further improve numerical weather prediction (NWP) models in presentation of physical processes specific for the Arctic; • analyse how much NWP models will benefit from new in-situ and satellite observations and improved coupling with sea ice models; • improve methods for post-processing NWP model output to meet the concrete user needs. To meet Objective C, we will • analyse the differential effects that the information contained in WMS has on economic decisions of the end-users. • use experimental economics to explore likely shapes of response functions reflecting the improved information and the critical threshold levels related to the quality of the information.

Understanding air mass transformations in the Arctic – observational and modelling strategies for moving forward

Felix Pithan
Understanding air mass transformations in the Arctic – observational and modelling strategies for moving forward To discuss the challenges and opportunities for progress we face in understanding and modelling Arctic air mass transformations and the associated boundary-layer properties, we are planning a 3.5 day workshop to be held in Stockholm from 6-9th November. We strive to bring together observationalists, fine-scale/large eddy simulations (LES) modellers and people working on numerical weather prediction (NWP) in climate models and the representation of clouds in such models.

WAMIZ - Waves in the MIZ – Modeling and Satellite Observations

Giacomo De Carolis
The aim of this project is to improve the estimation of sea-ice thickness by combining SAR image wave spectra and wave propagation modelling. We will focus on young sea-ice types which mainly compose the marginal ice zone (MIZ) during the freezing period, namely frazil, grease, pancake ice and thin floes. Such types of sea ice are even more vastly produced in the Arctic as a result of the decline of sea ice extent and volume, and is considered the primary source for sea ice fringing in the Antarctica seas through a process called the "pancake cycle". Achieving this goal requires two main activities: An improved theoretical investigation of the waves-in-ice propagation dynamics; and the refinement of the technique that converts the SAR instrument to a "synoptic wave buoy". Both tasks need an extensive validation that can be performed with wave buoys data. For sea-ice types that we are considering, viscous wave propagation models have demonstrated their ability to predict the observed spectral wave attenuations, although some concerns remain about the values to be assigned to ice viscosity, which are often difficult to interpret with physical considerations. The recently developed waves-in-ice model, called close packing model, seems to have good skills to predict both energy attenuation and wave dispersion as a function of wave frequency for very thin sea ice. However, to extend its applicability to thicker sea ice matrix, such as the one that can be found in the Antarctica oceans, further theoretical efforts have to be done.

WGNE - Activities of Working Group on Numerical Experimentation

Michael Ek
WGNE will support YOPP by encouraging modelling centres to participate in YOPP, and providing a forum to discuss results in the presence of model development and evaluation experts.

Wisconsin AWS - Collaborative Research: Antarctic Automatic Weather Station Program 2016-2019

Matthew Lazzara
The Antarctic Automatic Weather Station (AWS) program is one of the largest Antarctic meteorological observing networks and has collected over 38 years of observations. This network is critical for observing the weather and climate of the Antarctic surface and increasing our understanding of Antarctic meteorology. This project uses the surface conditions observed by the AWS network to determine how large-scale modes of climate variability impact Antarctic weather and climate, how the surface observations from the AWS network are linked to surface layer and boundary layer processes, and collaborates with other users of the observations. The AWS observations have been used in a variety of research efforts including boundary layer meteorology experiments near the South Pole, katabatic wind studies in a variety of locations, and wind flow studies along the Transantarctic Mountains, as well as flight forecasting, and long term climatology studies of key locations such as historic Byrd Station in West Antarctica. Today, the AWS project has roughly 60 AWS sites active in Antarctica. As related to the Year of Polar Prediction, operational activities such as weather forecasting have been a primary use of the observations, via numerical modeling (e.g. data assimilation) as well as direct use by forecasters. Further, the network is used for critical verification of numerical modeling efforts.