Surface Heat Budget over the North Sea in Climate Change Simulations

An ensemble of regional climate change scenarios for the North Sea is validated and analyzed. Five Coupled Model Intercomparison Project Phase 5 (CMIP5) General Circulation Models (GCMs) using three different Representative Concentration Pathways (RCPs) have been downscaled with the coupled atmosphere–ice–ocean model RCA4-NEMO. Validation of sea surface temperature (SST) against different datasets suggests that the model results are well within the spread of observational datasets. The ensemble mean SST with a bias of less than 1 ∘ C is the solution that fits the observations best and underlines the importance of ensemble modeling. The exchange of momentum, heat, and freshwater between atmosphere and ocean in the regional, coupled model compares well with available datasets. The climatological seasonal cycles of these fluxes are within the 95% confidence limits of the datasets. Towards the end of the 21st century the projected North Sea SST increases by 1.5 ∘ C (RCP 2.6), 2 ∘ C (RCP 4.5), and 4 ∘ C (RCP 8.5), respectively. Under this change the North Sea develops a specific pattern of the climate change signal for the air–sea temperature difference and latent heat flux in the RCP 4.5 and 8.5 scenarios. In the RCP 8.5 scenario the amplitude of the spatial heat flux anomaly increases to 5 W/m 2 at the end of the century. Different hypotheses are discussed that could contribute to the spatially non-uniform change in air–sea interaction. The most likely cause for an increased latent heat loss in the central western North Sea is a drier atmosphere towards the end of the century. Drier air in the lee of the British Isles affects the balance of the surface heat budget of the North Sea. This effect is an example of how regional characteristics modulate global climate change. For climate change projections on regional scales it is important to resolve processes and feedbacks at regional scales.

[1]  U. Mikolajewicz,et al.  Which complexity of regional climate system models is essential for downscaling anthropogenic climate change in the Northwest European Shelf? , 2018, Climate Dynamics.

[2]  M. Zahn,et al.  Effects of air-sea coupling over the North Sea and the Baltic Sea on simulated summer precipitation over Central Europe , 2017, Climate Dynamics.

[3]  A. Rutgersson,et al.  Characteristics of convective snow bands along the Swedish east coast , 2017 .

[4]  B. Ahrens,et al.  Simulation of snowbands in the Baltic Sea area with the coupled atmosphere-ocean-ice model COSMO-CLM/NEMO , 2017 .

[5]  A. Pozzer,et al.  Projection of North Atlantic Oscillation and its effect on tracer transport , 2016 .

[6]  Lars Bärring,et al.  Selecting regional climate scenarios for impact modelling studies , 2016, Environ. Model. Softw..

[7]  Berit Arheimer,et al.  Using flow signatures and catchment similarities to evaluate the E-HYPE multi-basin model across Europe , 2016 .

[8]  S. Schimanke,et al.  Thermal air–sea coupling in hindcast simulations for the North Sea and Baltic Sea on the NW European shelf , 2015 .

[9]  H. Dietze,et al.  Influence of sea level rise on the dynamics of salt inflows in the Baltic Sea , 2015 .

[10]  P. Samuelsson,et al.  Development and evaluation of a new regional coupled atmosphere–ocean model in the North Sea and Baltic Sea , 2015 .

[11]  S. Hagemann,et al.  Regionally coupled atmosphere‐ocean‐sea ice‐marine biogeochemistry model ROM: 1. Description and validation , 2015 .

[12]  R. Vautard,et al.  Regional climate modeling on European scales: a joint standard evaluation of the EURO-CORDEX RCM ensemble , 2014 .

[13]  T. Pohlmann,et al.  Assessment of a zoomed global model for the North Sea by comparison with a conventional nested regional model , 2014 .

[14]  T. Pohlmann,et al.  Comparison of three regional coupled ocean atmosphere models for the North Sea under today‘s and future climate conditions , 2014 .

[15]  T. Pohlmann,et al.  An uncoupled dynamical downscaling for the North Sea: Method and evaluation , 2013 .

[16]  T. Vihma,et al.  Resolved complex coastlines and land–sea contrasts in a high-resolution regional climate model: a comparative study using prescribed and modelled SSTs , 2013 .

[17]  H. Meier,et al.  Freshwater outflow of the Baltic Sea and transport in the Norwegian current: A statistical correlation analysis based on a numerical experiment , 2013 .

[18]  Günther Zängl,et al.  The ICON-1.2 hydrostatic atmospheric dynamical core on triangular grids – Part 1: Formulation and performance of the baseline version , 2013 .

[19]  A. Sterl,et al.  Wind extremes in the North Sea Basin under climate change: An ensemble study of 12 CMIP5 GCMs , 2012 .

[20]  Klaus Wyser,et al.  EC-Earth V2.2: description and validation of a new seamless earth system prediction model , 2012, Climate Dynamics.

[21]  Andreas Moll,et al.  NW European shelf under climate warming: implications for open ocean – shelf exchange, primary production, and carbon absorption , 2012 .

[22]  B. Müller-Karulis,et al.  Impact of Climate Change on Ecological Quality Indicators and Biogeochemical Fluxes in the Baltic Sea: A Multi-Model Ensemble Study , 2012, AMBIO.

[23]  H. Meier,et al.  Modeling Nutrient Transports and Exchanges of Nutrients Between Shallow Regions and the Open Baltic Sea in Present and Future Climate , 2012, AMBIO.

[24]  B. Müller-Karulis,et al.  Extremes of Temperature, Oxygen and Blooms in the Baltic Sea in a Changing Climate , 2012, AMBIO.

[25]  B. Gustafsson,et al.  Modeling the combined impact of changing climate and changing nutrient loads on the Baltic Sea environment in an ensemble of transient simulations for 1961–2099 , 2012, Climate Dynamics.

[26]  D. Jacob,et al.  Future projections of the surface heat and water budgets of the Mediterranean Sea in an ensemble of coupled atmosphere–ocean regional climate models , 2012, Climate Dynamics.

[27]  Jason T. Holt,et al.  Oceanic controls on the primary production of the northwest European continental shelf: model experiments under recent past conditions and a potential future scenario , 2012 .

[28]  H. Storch,et al.  Regional climate models add value to global model data, A Review and Selected Examples , 2011 .

[29]  J. Thepaut,et al.  The ERA‐Interim reanalysis: configuration and performance of the data assimilation system , 2011 .

[30]  S. Kanae,et al.  A physically based description of floodplain inundation dynamics in a global river routing model , 2011 .

[31]  E. Kjellström,et al.  Quality assessment of atmospheric surface fields over the Baltic Sea from an ensemble of regional climate model simulations with respect to ocean dynamics , 2011 .

[32]  K. Wyser,et al.  The Rossby Centre Regional Climate model RCA3: model description and performance , 2011 .

[33]  Ulf Hansson,et al.  21st century changes in the European climate: uncertainties derived from an ensemble of regional climate model simulations , 2011 .

[34]  Axel Andersson,et al.  The Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data – HOAPS-3 , 2010 .

[35]  Jason Lowe,et al.  The potential impacts of climate change on the hydrography of the northwest European continental shelf , 2010 .

[36]  P. Stott,et al.  Attribution of anthropogenic influence on seasonal sea level pressure , 2009 .

[37]  S. Hughes,et al.  Climatology of surface and near-bed temperature and salinity on the north-west European continental shelf for 1971–2000 , 2009 .

[38]  Jason T. Holt,et al.  Down‐welling circulation of the northwest European continental shelf: A driving mechanism for the continental shelf carbon pump , 2009 .

[39]  Michel Crépon,et al.  21st century climate change scenario for the Mediterranean using a coupled atmosphere–ocean regional climate model , 2008 .

[40]  D. Jacob,et al.  Modelling the exceptional Baltic Sea inflow events in 2002–2003 , 2004 .

[41]  R. Podzun,et al.  A coupled atmosphere/ice/ocean model for the North Sea and the Baltic Sea , 2003 .

[42]  Alexei G. Sankovski,et al.  Special report on emissions scenarios : a special report of Working group III of the Intergovernmental Panel on Climate Change , 2000 .

[43]  D. Jacob,et al.  A coupled high resolution atmosphere-ocean model for the BALTEX region , 2000 .

[44]  N. Gustafsson,et al.  Coupling of a High-Resolution Atmospheric Model and an Ocean Model for the Baltic Sea , 1998 .

[45]  G. Radach,et al.  Advective contributions to the heat balance of the german bight (LV Elbe 1) and the central north sea (OWS Famita) , 1998 .

[46]  G. Becker.  Sea surface temperature changes in the North Sea and their causes , 1996 .

[47]  P. Loewe.  Surface temperatures of the North Sea in 1996 , 1996 .

[48]  T. Pohlmann.  Predicting the thermocline in a circulation model of the North sea — part I: model description, calibration and verification , 1996 .

[49]  P. Loewe.  Surface temperatures of the North Sea in 1994 , 1995 .

[50]  A. Lane,et al.  The annual temperature cycle in shelf seas , 1995 .

[51]  G. Becker.  Beiträge zur Hydrographie und Wärmebilanz der Nordsee , 1981 .

[52]  H. Davies,et al.  A lateral boundary formulation for multi-level prediction models. [numerical weather forecasting , 1976 .

[53]  Momme Butenschön,et al.  Potential impacts of climate change on the primary production of regional seas: A comparative analysis of five European seas , 2016 .

[54]  J. Kwadijk,et al.  Recent Change—River Flow , 2016 .

[55]  B. Ahrens,et al.  New coupled atmosphere-ocean-ice system COSMO-CLM/NEMO: assessing air temperature sensitivity over the North and Baltic Seas , 2014 .

[56]  Wei Yang,et al.  River discharge to the Baltic Sea in a future climate , 2013, Climatic Change.

[57]  Shiyu Wang,et al.  Evaluation of the SMHI coupled atmosphere-ice-ocean model RCA4_NEMO , 2013 .

[58]  M. Rummukainen.  State‐of‐the‐art with regional climate models , 2010 .

[59]  Sylvain Bouillon,et al.  Simulating the mass balance and salinity of Arctic and Antarctic sea ice. 1. Model description and validation , 2009 .

[60]  U. Ulbrich,et al.  Factors contributing to the development of extreme North Atlantic cyclones and their relationship with the NAO , 2009 .

[61]  U. Willén,et al.  The Rossby Centre Regional Atmospheric Climate Model Part I: Model Climatology and Performance for the Present Climate over Europe , 2004 .

[62]  M. Meier,et al.  Simulated water and heat cycles of the Baltic Sea using a 3D coupled atmosphere-ice - ocean model , 2002 .

[63]  U. Willén,et al.  The development of the regional coupled ocean-atmosphere model RCAO , 2002 .

[64]  T. Pohlmann,et al.  The ICES-boxes approach in relation to results of a North Sea circulation model , 1997 .

[65]  R. Flather,et al.  A storm surge prediction model for the northern Bay of Bengal with application to the cyclone disaster in April 1991 , 1994 .

[66]  S. Bodin.  A predictive numerical model of the atmospheric boundary layer based on the turbulent energy equation , 1979 .