OSA = 6.6%

EVERYWHERE !!!EVERYTIME !!!

Ocean colors:

OSA: main idea

Some variables affect ocean surface dynamics.

Some others affect 0cean Surface Albedo.

Is there common variables ?

YES: wind speed, surface chlorophyll

How proceed ?First (small) step…

Jin et al. (2004) algorithm.

Cos(Solar Zenithal Angle)

Optical depth (m-1)

Adaptation : no optical depth dependencyRadiative 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 IPSLCM5A on the historical period

1.On-line albedo is computed from PISCES chlorophyll at surface

2.On-line albedo modifies the solar radiation input

SE

AW

IFS

HIS

TO

RIC

AL

CH

LO

RO

PH

YL

L (

mg

/m3)

SE

AW

IFS

AL

BE

DO

CH

LO

RO

PH

YL

L (

mg

/m3)

OSA: second test

How OSA-biophysical interactions impact ocean physics ?

On-line simulations with ORCA2-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%

Mar Jun Dec

Summer Summer

Oct

Winter

OSA CORE – Southern Ocean Temporal

Variability

OSA CORE – Impact on Surface Temperature

Con

trol

Alb

edo=

f(C

hl+

win

d)

Alb

edo=

f(w

ind)

Southern Ocean Seasonal CycleControl

Albedo=f(W)

Albedo=f(Chl,W)

OSA CORE – Impact on Mixed Layer Depth

Con

trol

Alb

edo=

f(C

hl+

win

d)

Alb

edo=

f(w

ind)

Control

A=f(W)

A=f(Chl,W)

Southern Ocean Seasonal Cycle

To be continued…Question ?