forecasts Cyril Palerme, Malte Müller, Arne Melsom Evaluation of the ice edge position in the European Arctic - Several verification scores have recently been suggested for evaluating the ice edge position - [...] between the ice edge lengths from the two data sets (observations and forecasts) Melsom et al., 2019 (Ocean Science) Influence of the length of the ice edges on the verification scores ⇒ The SPS is correlated [...] l Research Letters, 46, 4757–4763 23 Slide 1 Evaluation of the ice edge position in the European Arctic Datasets Sea ice probability (SIP) Modified Hausdorff Distance (MHD) Spatial Probability Score (SPS

Bremen 2019-06-17 - 19 DIE =Dcoast IE =DIIEE =D0 Ice Ocean 9th IICWG-DA, Bremen 2019-06-17 - 199th IICWG-DA, Bremen 2019-06-17 - 19 Ice Ocean Ice Ocean DIE ≫Dcoast IE =DIIEE =D0 Metrics compared: idealized [...] Sea ports to the Far East is ~40% shorther than via Suez ➢ Commercial shipping in the Arctic Ocean is becoming economically viable Three methods for defining edge position metrics 1. Displacement between [...] primary source of information for safe navigation in ice infested waters ● Retreating sea ice in the Arctic gives a potential for commercial ship traffic at high latitudes ● Northern sea route from North Sea

SIT bias impacts Arctic circulation wCDA of ocean hydrography: 30 members, monthly assimilation, 1980-2010 Constrained ocean hydrography reduces bias(SIT) ! Upper ocean: fresher Upper ocean: more saline + [...] skill? ice+ocean DA Strongly enhanced skill in melting season + sCDA of SIC: Is assimilation of ocean data helpful in the Arctic Basin? Is assimilation of ocean data helpful in the Arctic Basin? 23 May [...] Nordic Seas 2) Arctic basin The role of ocean and sea ice initialisation in the coupled Earth system OHT & winter SI May SIT & Sep SIC 11 1) Nordic Seas 2) Arctic basin The role of ocean and sea ice in

operational analysis) – Ocean 3DVar-FGAT with 5-day window (in-situ profiles, sea-level anomalies, SST) – Sea ice univariate 3DVar-FGAT of sea-ice concentration from passive microwave • Arctic sea-ice forecasts [...] and climate forecasting • Potential sources of predictability: slower-than-weather processes (e.g. ocean and sea ice) • Wide range of potential economic and societal applications: – Humanitarian planning [...] members; each forecast comes with 20 years of re-forecasts for calibration • Fully coupled atmosphere, ocean and sea ice (LIM2) • Seamless approach: same model and initial conditions across all forecasting systems

PowerPoint-Präsentation 9th IICWG-DA Leads and ridges in Arctic sea ice from RGPS data and high resolution sea-ice models Nils Hutter, Martin Losch, Lorenzo Zampieri Alfred Wegener Instiute Bremen, 19th [...] boundaries → Is the representation of deformation features realistic? Why do we care? Atmosphere ice ocean interactions in LKFs Prediction High resolution sea-ice simulations Scaling analysis of sea ice d [...] deformation product Covers 1996 to 2008 in the Amerasian Basin Two MITgcm simulations 2 km resolution Pan-Arctic Simulation period 1992 (1995) – 2012 5 class ITD vs standard VP Hypothesis: Does stronger dependence

and G. Garric Mercator-Ocean, Ramonville Saint Agne, France mercator-ocean.eu/marine.copernicus.eu Univariate Sea Ice Analysis in the operational applications The Mercator ocean and sea-ice reanalysis [...] separate analyses : Ocean Analysis (SLA, InSitu Data from CORA3.2, SST) , IAU on (h,T,S,U,V) Unidata/univariate Sea Ice Analysis Sea Ice Concentration (OSI-SAF) SIC Error: 1% open ocean, linear from 25% to [...] Innovation (PSY4V3) OSI-SAF SIC Residu (PSY4V3) OSI-SAF SIC Misfits (Run using Ocean Bias only) Sept 2011 March 2012 The Mercator ocean and sea-ice system PSY4V3 2006-2018 hindcast experiment assimilating OSI-SAF

necessary to obtain a unique parameter set! ● Ocean observation (T & S) can be used to provide further constraint Parameter optimization of Arctic sea ice-ocean model by a micro-GA Experiment design ● An [...] Germany 2 Ocean Atmosphere Systems, Hamburg, Germany 3Jacobs University, Bremen, Germany Sumata, H., F. Kauker, M. Karcher, and R. Gerdes. (2019), Simultaneous parameter optimization of an Arctic sea ice-ocean [...] Arctic sea ice-ocean model, Mon. Wea. Rev., doi:10.1175/MWR-D-18-0375.1. Simultaneous optimization of Arctic sea-ice model parameters by a genetic algorithm Outline 1. Motivation / Objective 2. Method /

Labrador shelf was covered by a permanent but floating ice mass such as today’s ice cover of the Arctic Ocean. We finished our geological sampling work yesterday. Today and tomorrow are dedicated to collecting [...] the retreating ice stream. Instead, we aim at reconstructing the dynamic history of Labrador shelf ocean currents through the past few thousand years with these cores. At the end of the last glacial, when [...] large-scale environmental catastrophe, and it resulted in a significant disturbance of the established ocean current system on the Labrador shelf. On the long sediment cores, we will carry out different types

al., 2017 Global FESOM2 setup with 4.5 km Arctic Ocean Sea ice dynamics 𝐷(𝑚𝒖) 𝐷𝑡 = −𝑚𝑓*𝒌 ×𝒖 + 𝝉𝒂 + 𝝉𝒘 −𝑚𝑔∆𝐻 + 𝛻 6 𝝈 Coriolis force a/s and ocean drag Sea Surface tilt Ice interaction Ice [...] not scale well FESOM2 throughput depending on NEVP (4.5km Arctic Ocean setup, 1728 cores) At about 650 NEVP the sea ice code cost as much as ocean code. Scalability of different model computational cores [...] From this To this Same computational cost Ice thickness, 4.5 km resolution Arctic setup Finite Element (volumE) Sea Ice Ocean Model FESOM Solves: • hydrostatic primitive equations • sea ice equations Domain:

in the Arctic: the AWI’s Hausgarten observatory in the Fram Strait, where experts from various disciplines are investigating all aspects of the ecosystem, from the water’s surface to the ocean depths, [...] in order to determine the impacts of climate change on biodiversity in the Arctic. After roughly a month underway, in mid-September Polarstern will reach the Norwegian port of Tromsø, where she’ll receive [...] her final preparations for the one-year-long MOSAiC expedition, prior to leaving for the Central Arctic on 20 September.