OCEAN SURFACE ALBEDO a step forward in understanding

OCEAN SURFACE ALBEDO: a step forward in understanding the potential role of the biogeochemistry on the SOLAS interactions. R. Séférian 1, 3, Madec G. 2, Salas D. 3, Bopp L. 1 1 IPSL/LSCE/BIOMAC, IPSL/LOCEAN, 3 METEO-FRANCE/CNRM/GMGEC/ASTER 2

OSA = 6. 6% EVERYWHERE !!! EVERYTIME !!!

Ocean colors:

OSA: main idea Some variables affect ocean surface dynamics. Some others affect 0 cean Surface Albedo. Is there common variables ? YES: wind speed, surface chlorophyll

How proceed ? First (small) step… Jin et al. (2004) algorithm. Optical depth (m-1) Cos(Solar Zenithal Angle) Adaptation : no optical depth dependency Radiative model column

OSA: first test How OSA-biophysical interactions impact chlorophyll concentrations at surface ? Off-line simulations with PISCES forced by monthly means of the coupled climate model IPSLCM 5 A on the historical period 1. On-line albedo is computed from PISCES chlorophyll at surface 2. On-line albedo modifies the solar radiation input

CHLOROPHYLL (mg/m 3) HISTORICAL SEAWIFS

CHLOROPHYLL (mg/m 3) ALBEDO SEAWIFS

OSA: second test How OSA-biophysical interactions impact ocean physics ? On-line simulations with ORCA 2 -LIM-PISCES forced by CORE Climatological FORCING Package 1. On-line albedo is computed from climatology of surface chlorophyll (CORE) and climatology of wind speed (CORE) 2. On-line albedo modifies the solar radiation input

OSA CORE Min: 6. 02% Max: 9. 5%

OSA CORE – Southern Ocean Temporal Variability Summer Winter Mar Jun Oct Dec

Albedo=f(Chl+wind) Albedo=f(wind) Control OSA CORE – Impact on Surface Temperature Southern Ocean Seasonal Cycle Control Albedo=f(W) Albedo=f(Chl, W)

Albedo=f(Chl+wind) Albedo=f(wind) Control OSA CORE – Impact on Mixed Layer Depth Southern Ocean Seasonal Cycle Control A=f(W) A=f(Chl, W)

To be continued… Question ?