1. Validation of the IPSL models used for Mediterranean climate studies
Laurent Li
Laboratoire de Météorologie Dynamique (LMD)
Institut Pierre-Simon Laplace (IPSL)
CNRS/UPMC, Paris, France
Mediterranean climate modelling workshop, Trieste, Oct 2008

2. Who we are IPSL/LMD IPSL: a federation of 5 laboratories (700 persons)
And several institutions

3. IPSL Earth system model
Continents
Atmosphère
Océan
Surface continentale
Sol et végétation
Circulation
atmosphérique
Physique
Circulation Océanique
Glace de mer
LMDz
ORCHIDEE
PISCES
INCA
STOMATE
ORCALIM C0 2
Carbone
Biogéochimie
continentale et
Biologie marine
Chimie
Gaz
&
Aérosols
DMS
Nutritifs
CH4, COV
Continents
Atmosphère
Océan
Surface continentale
Sol et végétation
Circulation
atmosphérique
Physique
Circulation Océanique
Glace de mer
ORCHIDEE
ORCHIDEE
LMDz
LMDz
ORCALIM
ORCALIM
Circulation
Circulation Océanique
atmosphérique
Glace de mer
Physique
Sol et végétation
STOMATE
STOMATE
PISCES
PISCES
Biogéochimie
Biogéochimie
Biogéochimie
Biogéochimie et et
continentale
continentale
Biologie marine
Biologie marine
Carbone
Carbone
Carbone
Carbone C0 C0
Carbone
Carbone 2 2
INCA
INCA
CH4, COV
CH4, COV
Chimie
Chimie
DMS
DMS
Chimie
Chimie
Aérosols
Aérosols
Gaz
Gaz
&
&
Nutritifs
Nutritifs
Aérosols

4. The IPSL-CM4 climate model
Atmosphere: LMDZ-4
Land: ORCHIDEE
Ocean: ORCA
Sea-ice: LIM
Coupler: OASIS-3
Medium resolution:
LMDZ 96x71x19 - ORCALIM : 2°

5. LMDZ-Mediterranean model
LMDZ-Med is a global atmospheric GCM with variable grid and a zoom over the Mediterranean basin. Local resolution: 30 km.
It is run as a regional climate model, with nudging conditions (every 6 hours) from a global model (LMDZ-g, ERA40, IPCC, etc.) at low resolution outside the zoom. The model is free to have its own behaviours inside the zoom.

6. IPCC-A2 scenarios regionally-enhanced with LMDZ-Med IPSL CNRM GFDL
Middle of
the 21st century
End of
the 21st
century dT dP

7. Changes (2070/2099 minus present) of seasonal extreme precipitations
(30-year return values, from GEV distribution). Units: mm/day

8. Two-way (self-) nesting between LMDZ-regional and LMDZ-global

9. Schematic of the quartriple coupling in IPSL
Global oceanic
model (ORCA2)
Global
Med Sea oceanic
model (MED8)
Regional
Schematic of the quartriple coupling in IPSL

10. SST from coupled model (MED8-LMDZr)
Jan
Apr
SST from coupled model
(MED8-LMDZr)
Jul
Oct

11. SST from coupled model (MED8-LMDZr-LMDZg)
Jan
Apr
SST from coupled model
(MED8-LMDZr-LMDZg)
Jul
Oct

12. Climatological SST (AMIP)
Jan
Apr
Climatological SST (AMIP)
Jul
Oct

13. Simulations planned in CIRCE
Regional O-A coupled model (MED8 + LMDZr) used for the scenario A1B from 1951 to 2050 (either IPSL or MPI-M global inputs).
Quartriple coupled model (MED8 + LMDZr + LMDZg + ORCA2) used for the scenario A1B from 1951 to 2050.

14. An example of the two-way nesting atmospheric system
Two configurations:
LMDZ-regional forced by prescribed lateral boundary conditions;
Two-way nesting system between LMDZ-regional and LMDZ-global.
Two experiments (10 years for each simulation):
ObsVeg: Observed Vegetation of present day,
NatVeg: Natural vegetation in the Mediterranean basin – idealized situation without any anthropogenic land use (statistical model).

15. Difference (NatVeg – ObsVeg)
Precipitation
T2m
2-way
1-way
Precipitation
T2m

16. Difference (NatVeg – ObsVeg)
Precipitation
T2m
Regional
Global
Precipitation
T2m

17. An example of LMDZr and LMDZg two-way nesting system for climate change scenario (Yangtze River Basin)

18. Annual-mean rainfall (mm/d) (top), and its future variation (bottom: 2050-2000)
LMDZ-global
LMDZ-regional
LMDZ-sn

19. An example of LMDZr coupled to a 50-m constant-depth slab model of the Med Sea
This study is designed to investigate how large-scale synoptic processes exert their influences on the Mediterranean regional climate.
Some synoptic perturbations are artificially filtred out from the lateral boundary conditions of the LMDZ-mediterranean model.

20. Experimental design schematic
CTRL
NoSynExtra
climatological BC
6-hr varying BC
6-hr varying BC
NoSyn
NoSynTropi
6-hr varying BC
climatological BC
climatological BC

21. January 2-m temperature (K)
CTRL
NoSynExtra - CTRL
NoSyn - CTRL
NoSynTropi - CTRL

22. January precipitation (mm/day)
CTRL
NoSynExtra - CTRL
NoSyn - CTRL
NoSynTropi - CTRL

23. Geopotential (NoSynExtra – CTRL)
300 mb
500 mb
850 mb
1000 mb

24. Suppression of extratropical synoptic perturbations makes a negative-phase NAO situation, i.e. more precipitation and warmer temperature in the south, but reverse in the north.
Suppression of tropical synoptic perturbations makes a more uniform cooling and drying (but weak) in the domain.

25. Perspectives more resolution at regional scale
more interactivity in the system
L.F. Richardson’s view of numerical weather prediction (1920s) (painting: François Schuiten, 2000)