Framtidens Östersjön – resultat från oceanografisk modellering

1. Framtidens Östersjön – resultat från oceanografisk modellering Markus Meier SMHI, Norrköping markus.meier@smhi.se

2. Variabler • Salthalt • Vattenstånd • Temperatur • Havsis

3. ice ocean OASIS Dtmod atmos rivers landsurf Dtcoup The coupled system RCAO RCA: 44 km, 30 min RCO: 11 km, 10 min Coupling timestep: 3 h RCO RCA Model domain, covering most of Europe and parts of the North Atlantic Ocean and Nordic Seas. Only the Baltic Sea is interactively coupled. The coupling scheme of RCAO. Atmosphere and ocean/ice run in parallel. Döscher et al. (2002)

4. Salthalt Gotlandsdjupet Figure 1. Median profiles of salinity at monitoring station BY15 for present climate 1961-1990 (black solid line, shaded areas indicate the +/- 2 standard deviation band calculated from two-daily values for 1903-1998) and in projections for 2071-2100 (colored lines). In (a) only effects from wind changes are considered whereas in (b) projections based upon wind and freshwater inflow changes are shown. Numbers in the legend correspond to the different scenario runs (see Tab.1). The figure is taken from Meier et al. (2006, Fig.2).

5. Vattenstånd Figure 2. Simulated winter mean sea level (in cm) in present climate (upper left panel) and in three selected regional scenarios relative to the mean sea level 1903-1998: `low case' scenario assuming a global average sea level rise of 9 cm (upper right panel), `ensemble average' scenario assuming a global average sea level rise of 48 cm (lower left panel), and `high case' scenario assuming a global average sea level rise of 88 cm (lower right panel). Land uplift is considered.

6. Vattenstånd Figure 3. Simulated 100-year surges (in cm) in present climate (upper left panel) and in three selected regional scenarios relative to the mean sea level 1903-1998: `low case' scenario assuming a global average sea level rise of 9 cm (upper right panel), `ensemble average' scenario assuming a global average sea level rise of 48 cm (lower left panel), and `high case' scenario assuming a global average sea level rise of 88 cm (lower right panel). Land uplift is considered. The figure is taken from Meier (2006, Fig.23) with kind permission of Springer Science and Business Media.

7. Figure 4. Annual mean SST (in °C) in present climate 1961-1990 (upper left), annual mean bias of simulated present climate compared to climatological data (upper right), and annual mean SST changes for the ensemble average (ECHAM4 and HadAM3H) of the B2 (lower left) and A2 (lower right) emission scenarios. The figure is taken from Meier (2006, Figs.13 and 14) with kind permission of Springer Science and Business Media. Ytvattentemperatur

8. Figure 5. Seasonal mean SST differences between the ensemble average scenario and simulated present climate (in °C): DJF (upper left), MAM (upper right), JJA (lower left), and SON (lower right). The figure is taken from Meier (2006, Fig.13) with kind permission of Springer Science and Business Media. Ytvattentemperatur

9. Figure 6. Annual mean temperature change (in °C) in 0-3, 18-21, 30-33, and 78-84 m depths (top to bottom rows) in regional scenario simulations driven by HadAM3H/A2, HadAM3H/B2, ECHAM4/A2, and ECHAM4/B2 (left to right columns). Temperature changes smaller than 1°C are shown without color and temperature changes larger than 5°C are shown in black. Temperatur

10. Figure 7. Mean number of ice days averaged for RCAO-H and RCAO-E: control (left panel), control, B2 scenario (middle panel), and A2 scenario (right panel).Figure is adoptedfrom Meier et al. (2004). Havsis

11. Figure 8. Mean annual cycle of ice cover. The black solid curve denotes the observed mean time evolution of ice area for the period 1963/64-1978/79 and the shaded area shows the range of variability defined by one added or subtracted standard deviation. In addition, the simulated mean seasonal ice cover is shown: RCAO-H (blue dashed), RCAO-E (green dashed), RCA1CTL (red dashed), RCAO-H/B2 (blue solid), RCAO-E/B2 (green solid), RCA1SCE (red solid), RCAO-H/A2 (blue dotted), RCAO-E/A2 (green dotted). Figure is adopted from Meier et al. 2004). Havsis

12. Figure 9. Scatterplot of annual maximum ice extent and winter mean (December through February) air temperature at Stockholm: RCAO-H (plus signs), RCAO-E (triangles), control (blue), B2 (green), A2 (red). Figure is adopted from Meier et al. 2004). Havsis

13. References • Meier, H.E.M., R. Döscher, and A. Halkka, 2004: Simulated distributions of Baltic sea-ice in warming climate and consequences for the winter habitat of the Baltic ringed seal. Ambio, 33, 249-256. • Meier, H.E.M., 2006: Baltic Sea climate in the late twenty-first century: a dynamical downscaling approach using two global models and two emission scenarios. Clim. Dyn., 27(1), 39-68, doi: 10.1007 / s00382-006-0124-x. • Meier, H.E.M., E. Kjellström, and L.P. Graham, 2006: Estimating uncertainties of projected Baltic Sea salinity in the late 21st century. Geophys. Res. Lett., Vol. 33, No. 15, L15705, doi: 10.1029/2006GL026488.

14. Emission scenario (A2, B2) GCM (HadAM3H, HadAM3P, ARPEGE, ECHAM4/OPYC3, ECHAM5/MPI-OM) RCM (RACMO, RCAO, HadRM3P, HIRHAM, CLM, CHRM ) 1961-1990, 2071-2100 Delta change wind and P-E RCO HBV salinity runoff 1902-1998 Model hierachy