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08/07/2015 Our Common Future Under Climate Change
Fabrice Chauvin, Hervé Douville and Aurélien Ribes
CNRM-GAME, Toulouse
08/07/2015 Our Common Future Under Climate Change
P = E - div(VQ) - + o(ε)
where
P : rainfall
E : evaporation
-div(VQ) : moisture convergence
: total column water tendency
dt
dW
Water Budget Equation
dt
dW
08/07/2015 Our Common Future Under Climate Change
Compositing Method
For each TC, the lifetime
maximum of the 5°x5°
spatial average is selected.
-
Domain average rainfall
percentiles are calculated
-
Corresponding other terms
of the water budget are
calculated
08/07/2015 Our Common Future Under Climate Change
ERA-Interim
1979-2013
CNRM-CM5s Historical
1945-1994
Comparing model, reanalysis and
observations
Data assimilation
IBTracs + TRMM
+ ERA-Interim
1998-2013
IBTracs
ERA-I
CNRM-CM5s
Hist RCP8.5
08/07/2015 Our Common Future Under Climate Change
Future change in rainfall
Curves correspond to
decreasing size of the domain
over which the spatial average
have been calculated
More than a over domain,
average is performed over the
Nth highest values in the 5°x5°
box
N = 1 4 16 25 100 400
08/07/2015 Our Common Future Under Climate Change
Future change in rainfall
1 x Clausius-Clapeyron rate
2 x Clausius-Clapeyron rate
in % per Kelvin
08/07/2015 Our Common Future Under Climate Change
• Water budget is dominated by moisture convergence
in the model and reanalysis
• Both model and reanalysis understimate TC rainfall
due to low values of maximum winds
• As expected from theoretical considerations, the
highest local rainfall increase at twice the Clausius-
Clapeyron rate due to both increase in moisture and
wind
Summary
08/07/2015 Our Common Future Under Climate Change
Supplementay 1:
Future change in Moisture Convergence
1 x Clausius-Clapeyron rate
2 x Clausius-Clapeyron rate
in % per Kelvin
08/07/2015 Our Common Future Under Climate Change
Supplementary 2:
Future change in Evaporation
1 x Clausius-Clapeyron rate
2 x Clausius-Clapeyron rate
in % per Kelvin
