Contract Detail

MEASUREMENT OF THE AEROSOL INTERACTION WITH CLOUDS AND FORCING OF CLIMATETHE WORK AT STANFORD UNIVERSITY WILL INVOLVE NUMERICAL MODELING. THE MODEL TO BE USED IS GATOR-GCMOM A ONE-WAY NESTED GLOBAL-THROUGH-LOCAL GAS AEROSOL TRANSPORT RADIATION GENERAL CIRCULATION MESOSCALE AND OCEAN MODEL. GATOR-GCMOM WILL BE RUN IN GLOBAL-THROUGH-LOCAL NESTED MODE WITH HIGH-RESOLUTION GRIDS PLACED OVER ONE WORLD REGION IN WHICH STRONG SPATIAL GRADIENTS IN AEROSOL OPTICAL DEPTH ARE IDENTIFIED FROM MODTS DATA. THE TARGETED AREA WILL MOST LIKELY BE EITHER NEAR BRAZIL CHINA OR THE WEST COAST OF THE U.S. THE RESOLUTION OF THE FINEST NESTED GRID WILL BE 4-5 KM. SIMULATIONS WILL BE RUN FOR TWO MONTHS OF THE YEAR TO BE DETERMINED. FOR THE SELECTED REGION THE MODEL WILL BE RAN TWICE. THE FIRST WITH ALL AEROSOLS AND THE SECOND WITH OTHER BIOMASS BURNING AEROSOLS (OR ANTHROPOGENIC AEROSOLS DEPENDING ON LOCATION). AFTER THE FIRST RUN RESULTS WILL BE COMPARED WITH OBSERVATIONS TO DETERMINE WHETHER THE MODEL CORRECTLY REPRODUCES THE AEROSOL CHARACTERISTICS AS MEASURED BY SATELLITE. RESULTS WILL ALSO BE EXAMINED TO DETERMINE WHETHER THE MODEL REPRODUCES CLOUD PRECIPITATION AND RADIATION FIELDS REASONABLY AND WHETHER IT REPRODUCES THE OBSERVED CORRELATIONS BETWEEN THESE VARIABLES. THIS IS AN IMPORTANT CHECK OF THE MODEL PHYSICS AND EMISSIONS. ASSUMING THAT THE MODEL ADEQUATELY SIMULATES THE AEROSOL-CLOUD ENVIRONMENT AS OBSERVED FROM SATELLITE WE WILL ANALYZE THE DIFFERENCES BETWEEN RUNNING THE MODEL WITH ELEVATED AEROSOL AND RUNNING WITHOUT SUCH AEROSOLS. THE DIFFERENCES IN AEROSOL-CLOUD CORRELATIONS BETWEEN THESE RUNS WILL GIVE A CLEAR INDICATION OF THE TRUE EFFECT AEROSOL HAS ON CLOUDS AND PRECIPITATION. MODEL DIAGNOSTICS TO CONSIDER INCLUDE DIFFERENCES IN CLOUD DROPLET SIZE CLOUD DROPLET NUMBER CONCENTRATION CLOUD TOP HEIGHTS CLOUD COVER DISTRIBUTION OF THERMODYNAMIC PHASE EXTENT AND TOTAL AMOUNT OF PRECIPITATION AND AVERAGE RAIN RATE. ONLY THE MODEL CAN UNAMBIGUOUSLY SEPARATE AEROSOL EFFECTS FROM METEOROLOGICAL EFFECTS BUT ONLY THE OBSERVATIONS CAN HOLD THE MODEL ACCOUNTABLE TO REALITY. DIFFERENCES BETWEEN SIMULATIONS WILL BE ANALYZED IN GRAPHICAL AND STATISTICAL FORM. RESULTS INCLUDING A COMPARISON WITH SATELLITE DATA WILL BE WRITTEN UP FOR PUBLICATION.

MEASUREMENT OF THE AEROSOL INTERACTION WITH CLOUDS AND FORCING OF CLIMATETHE WORK AT STANFORD UNIVERSITY WILL INVOLVE NUMERICAL MODELING. THE MODEL TO BE USED IS GATOR-GCMOM A ONE-WAY NESTED GLOBAL-THROUGH-LOCAL GAS AEROSOL TRANSPORT RADIATION GENERAL CIRCULATION MESOSCALE AND OCEAN MODEL. GATOR-GCMOM WILL BE RUN IN GLOBAL-THROUGH-LOCAL NESTED MODE WITH HIGH-RESOLUTION GRIDS PLACED OVER ONE WORLD REGION IN WHICH STRONG SPATIAL GRADIENTS IN AEROSOL OPTICAL DEPTH ARE IDENTIFIED FROM MODTS DATA. THE TARGETED AREA WILL MOST LIKELY BE EITHER NEAR BRAZIL CHINA OR THE WEST COAST OF THE U.S. THE RESOLUTION OF THE FINEST NESTED GRID WILL BE 4-5 KM. SIMULATIONS WILL BE RUN FOR TWO MONTHS OF THE YEAR TO BE DETERMINED. FOR THE SELECTED REGION THE MODEL WILL BE RAN TWICE. THE FIRST WITH ALL AEROSOLS AND THE SECOND WITH OTHER BIOMASS BURNING AEROSOLS (OR ANTHROPOGENIC AEROSOLS DEPENDING ON LOCATION). AFTER THE FIRST RUN RESULTS WILL BE COMPARED WITH OBSERVATIONS TO DETERMINE WHETHER THE MODEL CORRECTLY REPRODUCES THE AEROSOL CHARACTERISTICS AS MEASURED BY SATELLITE. RESULTS WILL ALSO BE EXAMINED TO DETERMINE WHETHER THE MODEL REPRODUCES CLOUD PRECIPITATION AND RADIATION FIELDS REASONABLY AND WHETHER IT REPRODUCES THE OBSERVED CORRELATIONS BETWEEN THESE VARIABLES. THIS IS AN IMPORTANT CHECK OF THE MODEL PHYSICS AND EMISSIONS. ASSUMING THAT THE MODEL ADEQUATELY SIMULATES THE AEROSOL-CLOUD ENVIRONMENT AS OBSERVED FROM SATELLITE WE WILL ANALYZE THE DIFFERENCES BETWEEN RUNNING THE MODEL WITH ELEVATED AEROSOL AND RUNNING WITHOUT SUCH AEROSOLS. THE DIFFERENCES IN AEROSOL-CLOUD CORRELATIONS BETWEEN THESE RUNS WILL GIVE A CLEAR INDICATION OF THE TRUE EFFECT AEROSOL HAS ON CLOUDS AND PRECIPITATION. MODEL DIAGNOSTICS TO CONSIDER INCLUDE DIFFERENCES IN CLOUD DROPLET SIZE CLOUD DROPLET NUMBER CONCENTRATION CLOUD TOP HEIGHTS CLOUD COVER DISTRIBUTION OF THERMODYNAMIC PHASE EXTENT AND TOTAL AMOUNT OF PRECIPITATION AND AVERAGE RAIN RATE. ONLY THE MODEL CAN UNAMBIGUOUSLY SEPARATE AEROSOL EFFECTS FROM METEOROLOGICAL EFFECTS BUT ONLY THE OBSERVATIONS CAN HOLD THE MODEL ACCOUNTABLE TO REALITY. DIFFERENCES BETWEEN SIMULATIONS WILL BE ANALYZED IN GRAPHICAL AND STATISTICAL FORM. RESULTS INCLUDING A COMPARISON WITH SATELLITE DATA WILL BE WRITTEN UP FOR PUBLICATION.