Numerical modeling of upwelling filaments in the Gulf

Numerical modeling of upwelling filaments in the Gulf of Finland Edith Soosaar, Urmas Raudsepp Marine Systems Institute Tallinn University of Technology

Outline Gulf of Finland p Upwelling in the Gulf of Finland p Model setup (three different setups): p n n n p purpose, setup, results. Conclusion

Gulf of Finland

Upwelling and upwelling filaments 6 July 2006 p 7 July 2006 p 11 July 2006 p

First setup Purpose: to find most favorable wind for upwelling filaments formation p Setup: p n n p Model area: Baltic Sea Horizontal grid step (5. 5 km) 10 vertical layers (two layer stratification) Constant wind (8 m/s) from eight cardinal point Result: favorable for Estonian coast east wind and for Finland coast west wind

Second setup p Purpose: to observe formation of upwelling and upwelling filaments p Setup: n n n Area: Gulf of Finland Horizontal grid step (2. 7 km) 20 vertical layers Constant wind (8 m/s) from east and west Measured temperature and salinity stratification.

Results of second setup p p Upwelling occurred within 1. 5 days 3. -4. days starting to form filaments (3. 5 days) Anticyclonic eddies (7. 5 days) Mushroom head shaped structure

Third setup p Purpose: reality check p Setup: n n Same as previous but added Measured wind from (19. -29. July, 1999).

Results of third model setup

Conclusion p p p Most favorable for present area east and west wind. The location of filaments compare reasonably. Strength and offshore extent was underestimated in the model. Anticyclonic eddies turn filaments anti clockwise. More pronounced filaments had started to form mushroom head shape. Filaments tend to turn opposite direction. comparing with filaments on satellite temperature pictures.