EGU21-8728, updated on 04 Mar 2021
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Nemo-Nordic 2.0: Updated Baltic Sea model based on NEMO 4.0

Tuomas Kärnä1, Ida Ringgaard2, Vasily Korabel2, Adam Nord3, Patrik Ljungemyr3, Saeed Falahat3, Lars Axell3, Anja Lindenthal4, Simon Jandt-Scheelke4, Ilja Maljutenko5, and Svetlana Verjovkina5
Tuomas Kärnä et al.
  • 1Finnish Meteorological Institute, Finland
  • 2Danish Meteorological Institute, Denmark
  • 3Swedish Meteorological and Hydrological Institute, Sweden
  • 4Bundesamt für Seeschifffahrt und Hydrographie, Germany
  • 5Department of Marine Systems at Tallinn University of Technology, Estonia

We present Nemo-Nordic 2.0, the latest version of the operational marine forecasting model for the Baltic Sea used and developed in the Baltic Monitoring Forecasting Centre (BAL MFC) under the Copernicus Marine Environment Monitoring Service (CMEMS). The most notable differences between Nemo-Nordic 2.0 and its predecessor Nemo-Nordic 1.0 are the switch from NEMO 3.6 to NEMO 4.0 and an increase in horizontal resolution from 2 to 1 nautical mile. In addition, the model's bathymetry and bottom friction formulation have been updated. The model configuration was specially tuned to represent Major Baltic Inflow events. Focusing on a 2-year validation period from October 1, 2014, covering one Major Baltic Inflow event, Nemo-Nordic 2.0 simulates Sea Surface Height (SSH) well: centralized Root-Mean-Square Deviation (CRMSD) is within 10 cm for most stations outside the Inner Danish Waters. CRMSD is higher at some stations where small-scale topographical features cannot be correctly resolved. SSH variability tends to be overestimated in the Baltic Sea and underestimated in the Inner Danish Waters. Nemo-Nordic 2.0 represents Sea Surface Temperature (SST) and Salinity (SSS) well, although there is a negative bias around -0.5°C in SST. The 2014 Major Baltic Inflow event is well reproduced. The simulated salt pulse agrees well with observations in the Arkona basin and progresses into the Gotland basin in 3 to 4 months.

How to cite: Kärnä, T., Ringgaard, I., Korabel, V., Nord, A., Ljungemyr, P., Falahat, S., Axell, L., Lindenthal, A., Jandt-Scheelke, S., Maljutenko, I., and Verjovkina, S.: Nemo-Nordic 2.0: Updated Baltic Sea model based on NEMO 4.0, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8728,, 2021.

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