Tuning and assessment of the HYCOM-NORWECOM V2.1 biogeochemical modeling system for the North Atlantic and Arctic oceans

Abstract. The HYCOM-NORWECOM (HYbrid Coordinate Ocean Model–NORWegian ECOlogical Model) modeling system is used both for basic research and as a part of the forecasting system for the Arctic Marine Forecasting Centre through the MyOcean project. Here we present a revised version of this model. The present model, as well as the sensitivity simulations leading up to this version, have been compared to a data set of in situ measurements of nutrient and chlorophyll from the Norwegian Sea and the Atlantic sector of the Arctic Ocean. The model revisions having the most impact included adding diatoms to the diet of microzooplankton, increasing microzooplankton grazing rate and decreasing the silicate-to-nitrate ratio in diatoms. Model runs are performed both with a coarse- (~ 50 km) and higher-resolution (~ 15 km) model configuration, both covering the North Atlantic and Arctic oceans. While the new model formulation improves the results in both the coarse- and high-resolution model, the nutrient bias is smaller in the high-resolution model, probably as a result of the better resolution of the main processes and improved circulation. The final revised version delivers satisfactory results for all three nutrients as well as improved results for chlorophyll in terms of the annual cycle amplitude. However, for chlorophyll the correlation with in situ data remains relatively low. Besides the large uncertainties associated with observational data this is possibly caused by the fact that constant C:N- and Chl:N ratios are implemented in the model.

[1]  C. Hansen.  Simulated primary production in the Norwegian Sea-Interannual variability and impact of mesoscale activity , 2008 .

[2]  Laurent Bertino,et al.  Impact of data assimilation of physical variables on the spring bloom from TOPAZ operational runs in the North Atlantic , 2009 .

[3]  Laurent Bertino,et al.  Estimation of positive sum-to-one constrained zooplankton grazing preferences with the DEnKF: a twin experiment , 2012 .

[4]  M. Skogen,et al.  A user's guide to NORVECOM V2.0. the norwegian ecological model system , 1998 .

[5]  Annette Samuelsen,et al.  Anticyclonic eddies in the Norwegian Sea; their generation, evolution and impact on primary production , 2010 .

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

[7]  E. Carmack,et al.  Thermohaline circulation in the Arctic Mediterranean Seas , 1985 .

[8]  K. Taylor.  Summarizing multiple aspects of model performance in a single diagram , 2001 .

[9]  R. Hill,et al.  Description and evaluation , 1976 .

[10]  C. S. Wong,et al.  Climatological mean and decadal change in surface ocean pCO2, and net seaair CO2 flux over the global oceans , 2009 .

[11]  Peter R. Oke,et al.  TOPAZ4: an ocean-sea ice data assimilation system for the North Atlantic and Arctic , 2012 .

[12]  Dag L. Aksnes,et al.  Ecological modelling in coastal waters: Towards predictive physical-chemical-biological simulation models , 1995 .

[13]  Jerry Blackford,et al.  Ecosystem dynamics at six contrasting sites: a generic modelling study , 2004 .

[14]  Jason T. Holt,et al.  Error quantification of a high-resolution coupled hydrodynamic-ecosystem coastal-ocean model: Part 2. Chlorophyll-a, nutrients and SPM , 2007 .

[15]  A. Warn-Varnas,et al.  Near-surface circulation of the Nordic seas as measured , 1996 .

[16]  John A. Harrison,et al.  Sources and delivery of carbon, nitrogen, and phosphorus to the coastal zone: An overview of Global Nutrient Export from Watersheds (NEWS) models and their application , 2005 .

[17]  A. Sterl,et al.  The ERA‐40 re‐analysis , 2005 .

[18]  Collin S. Roesler,et al.  New insights on obtaining phytoplankton concentration and composition from in situ multispectral Chlorophyll fluorescence , 2010 .

[19]  Andreas Moll,et al.  Validation of the three-dimensional ECOHAM model in the German Bight for 2004 including population dynamics of Pseudocalanus elongatus , 2009 .

[20]  G. Huse,et al.  Shelf recruitment of Calanus finmarchicus off the west coast of Norway: role of physical processes and timing of diapause termination , 2009 .

[21]  C. Yentsch,et al.  Phytoplankton Nitrogen in the Oceans1 , 1958 .

[22]  A. Samuelsen,et al.  Influence of horizontal model grid resolution on the simulated primary production in an embedded primary production model in the Norwegian Sea , 2009 .

[23]  A. Borges,et al.  Nitrogen and carbon cycling in the North Sea and exchange with the North Atlantic—A model study, Part II: Carbon budget and fluxes , 2008 .

[24]  Le Traon,et al.  From satellite altimetry to Argo and operational oceanography: three revolutions in oceanography , 2013 .

[25]  Rainer Bleck,et al.  An oceanic general circulation model framed in hybrid isopycnic-Cartesian coordinates , 2002 .

[26]  Timothy P. Boyer,et al.  World ocean atlas 2001 : objective analyses, data statistics, and figures : CD-ROM documentation , 2002 .

[27]  Richard J. Geider,et al.  LIGHT AND TEMPERATURE DEPENDENCE OF THE CARBON TO CHLOROPHYLL a RATIO IN MICROALGAE AND CYANOBACTERIA: IMPLICATIONS FOR PHYSIOLOGY AND GROWTH OF PHYTOPLANKTON , 1987 .

[28]  L. Jonasson,et al.  Assessment of a physical-biogeochemical coupled model system for operational service in the Baltic Sea , 2012 .

[29]  Jan O. Backhaus,et al.  Convection and primary production in winter , 2003 .

[30]  M. Gosselin,et al.  Nitrogen uptake by heterotrophic bacteria and phytoplankton in Arctic surface waters , 2007 .

[31]  Ralph,et al.  Phytoplankton Nitrogen in the Oceans ] , 1999 .

[32]  C. Stow,et al.  Skill Assessment for Coupled Biological/Physical Models of Marine Systems. , 2009, Journal of marine systems : journal of the European Association of Marine Sciences and Techniques.

[33]  T. R. Anderson,et al.  Medusa-1.0: a new intermediate complexity plankton ecosystem model for the global domain , 2010 .

[34]  Momme Butenschön,et al.  Validation of the NEMO-ERSEM operational ecosystem model for the North West European Continental Shelf , 2012 .

[35]  J. Steele,et al.  The role of predation in plankton models , 1992 .

[36]  J. Backhaus,et al.  \'Phyto-convection\': the role of oceanic convection in primary production , 1999 .

[37]  P. Tréguer,et al.  Growth physiology and fate of diatoms in the ocean: a review , 2005 .

[38]  W. Richard,et al.  TEMPERATURE AND PHYTOPLANKTON GROWTH IN THE SEA , 1972 .