ESDD Earth System Dynamics Discussions ESDD Earth Syst. Dynam. Discuss. 2190-4995 Göttingen, Germany 10.5194/esd-2017-35 An Evaluation and Implementation of the Regional Coupled Ice-Ocean Model of the Baltic Sea Jakacki Jaromir https://orcid.org/0000-0001-7376-3090 1 Meler Sebastian 1 Institute of Oceanology of Polish Academy of Sciences No N N305 111636 European Regional Development Fund POIG 01.01.02-22-011/09 North Atlantic Treaty Organization NATO EAP.SFPP 984589 R013 DAIMON Ministerstwo Edukacji i Nauki projekt międzynarodowy współfinansowany 12 04 2017 2017 1 47 Copyright: © 2017 Jaromir Jakacki 2017 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://esd.copernicus.org/preprints/esd-2017-35/ The full text article is available as a PDF file from https://esd.copernicus.org/preprints/esd-2017-35/esd-2017-35.pdf

A three dimensional, regional coupled ice-ocean model based on the open-source Community Earth System Model has been developed and implemented for the Baltic Sea. The model consists of 66 vertical levels and has a horizontal resolution of approx. 2.3 km. The paper focuses on sea ice component results but the main changes have been introduced in the ocean part of the coupled model. The hydrodynamic part, being one of the most important components, has been also presented and validated. The ice model results were validated against the radar and satellite data, and the method of validation based on probability was introduced. In the last two decades satellite and model results show an increase in the ice extent over the whole Baltic Sea, which is an evidence of a negative trend in air temperature in recent decades and increasing of winter discharge from the catchment area.