Model set-up
description
Transcript of Model set-up
EGU, General Assembly 2011 , Vienna, Austria, 3 – 8 April 2011
MODELLING OF SALINITY AND TEMPERATURE VARIATION IN
THE BALTIC SEA DURING THE LAST TWO DECADES
S. Miladinova and A. Stips
EGU, General Assembly 2011 , Vienna, Austria, 3 – 8 April 2011
Model set-up
GETM (www.getm.eu)
Topography 1 nm by 1nm (www.io-
warnemuende.de/topography-of-the-baltic-
sea.html)
Sea level variations at the open boundary
(www.dmi.dk/dmi/tr07-09; www.ioc-
sealevelmonitoring.org)
Runoff from land (different sources )
Meteorological forcing (www.ecmwf.int)
Initial and boundary conditions for salinity and
temperature (Janssen et al. (1999);
nest.su.se/bed)
EGU, General Assembly 2011 , Vienna, Austria, 3 – 8 April 2011
Model domain
Horizontal grid - 628 x 371 (cells of 1 nm by 2 nm);
25 vertical layers of adaptive terrain-following coordinates;
Time step: 25 s for the barotropic and 750 s for the baroclinic mode;
Calculations are distributed to 48 processes;
The run is carried out on 4 clusters with 12 CPUs;
About 20 CPUs minutes for a month;
25 year run (1986–2010).
EGU, General Assembly 2011 , Vienna, Austria, 3 – 8 April 2011
Difference between observed and modeled daily mean sea levels at Landsort
EGU, General Assembly 2011 , Vienna, Austria, 3 – 8 April 2011
Model verification at Anholt station (1986 – 2010)
Correlation coefficient = 0.92RMSD = 2.8Standard deviation = 1.2
Correlation coefficient = 0.95RMSD = 1.5˚CStandard deviation = 1
EGU, General Assembly 2011 , Vienna, Austria, 3 – 8 April 2011
Model verification at Bornholm station
Correlation coefficient = 0.84RMSD = 2.4Standard deviation = 0.83
Correlation coefficient = 0.82RMSD = 2.7˚CStandard deviation = 1
EGU, General Assembly 2011 , Vienna, Austria, 3 – 8 April 2011
Model verification at LL7 station
Correlation coefficient = 0.84RMSD = 0.77Standard deviation = 1.5
Correlation coefficient = 0.89RMSD = 2.6˚CStandard deviation = 1
EGU, General Assembly 2011 , Vienna, Austria, 3 – 8 April 2011
Major Baltic inflow in 1993
EGU, General Assembly 2011 , Vienna, Austria, 3 – 8 April 2011
Salinity simulation of the major inflow
EGU, General Assembly 2011 , Vienna, Austria, 3 – 8 April 2011
A minor Baltic inflow in the autumn of 2001
EGU, General Assembly 2011 , Vienna, Austria, 3 – 8 April 2011
Temperature in the case of minor inflow (2001)
EGU, General Assembly 2011 , Vienna, Austria, 3 – 8 April 2011
Recent inflow events (2006 – 2008)
Drogden Sill
Darss Sill
Short Info for the inflow events http://www.io-warnemuende.de
barotropic inflow
baroclinic inflow
EGU, General Assembly 2011 , Vienna, Austria, 3 – 8 April 2011
Bottom and surface salinity at Bornholm during the last 5 years
EGU, General Assembly 2011 , Vienna, Austria, 3 – 8 April 2011
Mean surface/bottom temperature in comparison to the mean values of the last 25 years
At the surface
At the bottom
EGU, General Assembly 2011 , Vienna, Austria, 3 – 8 April 2011
Conclusions
The model is capable to reproduce reasonably the Baltic inflow events;
Better calculation of the near bottom temperature in the deep regions is crucial;
Higher inflow activity is detected;
Frequent occurrence of moderate/minor barotropic and baroclinic inflow events ventilate “continuously” the Borholm Deep and the Gdansk Deep;
EGU, General Assembly 2011 , Vienna, Austria, 3 – 8 April 2011
ACKNOWLEDGEMENTS:
We are grateful to the Baltic Nest Institute, Stockholm University for making available the hydrographic data trough the Baltic Environmental Database.
Special thanks are given to the GETM developers for providing and maintaining the model, and in particular to Richard Hofmeister for developing and implementing the adaptive vertical coordinates.
Info:The monthly mean hydrodynamical model results will be uploaded on the Environmental Marine Information
System (http://emis.jrc.ec.europa.eu)