Simulation of Seasonal and Interannual Variability in the

Caspian Sea

W. Paul BudgellDept. of Physics and Physical Oceanography,

Memorial University of Newfoundland

Ralf Toumi, Andrew Singleton, Catherine Reifen, James Farley Nicolls

Dept. of Physics, Imperial College, London

Outline of Talk

• Background/Motivation• ROMS Implementation• Forcing• Some Results• Conclusions/Future work

Motivation

• Regional climate change – but first we must gain confidence on recent history and variability

• Dynamical downscaling, but after Gildas Cambon’s talk will revisit statistical downscaling

• Regional coupled environmental model• Operational applications in oil spills, localized

wave climate, contaminant /salt/aerosol transport

Caspian Sea Bathymetry (m)

From: Elguindi and Giorgi, Clim. Dyn. 26 (2006) 395-379.

CSL in IPCC 20th Century Simulations

Projected Changes in CSL

From: Elguindi and Giorgi, Clim. Dyn. 26 (2006) 395-379.

WRF Simulation Nov. 1996

ROMS Set-Up

• Kate Hedström’s branch• Ice dynamics/thermodynamics – shallow• Wetting-drying (dcrit = 0.2 m)• Sea level is dependent upon (E-P)• 4 km resolution• 32 and 20 vertical levels• Vtransform=2, Vstretching=2• θs=8, θb=0.4, hc=10 m

ROMS Set-Up Cont’d

• River inflow specified for 6 largest rivers• Atmospheric forcing from ERA40, ERA Interim,

or WRF (down-scaling ERA40)• Runs for 1958-2001 (ERA40), 1989-2008 (ERA

Interim), or 1980-2001 (WRF)• Climate sensitivity run with reduced river

inflow for 1980-2001 (’2045-2066’)

Some Results

ROMS Sea Ice Extent

SST Comparison

Caspian Sea Levels

Conclusions/Future Work

• E-P sea level + wetting/drying + sea ice works• Change in surface area important• Very sensitive to river runoff• WRF higher wind speeds improve

evaporation• ROMS-WRF coupling needed• ROMS-WRF-SWAN coupling needed

Job Opportunity

• Dept. of Physics, Imperial College, London is hiring post-doc to conduct development of Caspian Regional Environmental Model.

• CREM based on coupled ROMS-WRF-SWAN for the Caspian Sea