Presentation on theme: "Validation of the IPSL models used for Mediterranean climate studies Laurent Li Laboratoire de Météorologie Dynamique (LMD) Institut Pierre-Simon Laplace."— Presentation transcript:
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
IPSL: a federation of 5 laboratories (700 persons) And several institutions Who we are IPSL/LMD
IPSL Earth system model Sol et végétation Circulation atmosphérique Physique Glace de mer LMDzORCHIDEE PISCES INCA STOMATE ORCALIM LMDzORCHIDEE PISCES INCA STOMATE ORCALIM C0 2 Carbone Biogéochimie continentale Biogéochimieet Biologie marine C0 2 Carbone Biogéochimie continentale Biogéochimieet Biologie marine Chimie Gaz & DMS Nutritifs Chimie CH4, COV Aérosols Chimie Gaz & Aérosols DMS Nutritifs Chimie CH4, COV Aérosols Circulation Océanique
Atmosphere: LMDZ-4 Land: ORCHIDEE Ocean: ORCA Sea-ice: LIM Coupler: OASIS-3 Medium resolution: LMDZ 96x71x19 - ORCALIM : 2° The IPSL-CM4 climate 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. LMDZ-Mediterranean model
IPCC-A2 scenarios regionally-enhanced with LMDZ-Med IPSLCNRMGFDL Middle of the 21st century End of the 21st century Middle of the 21st century End of the 21st century T P
Changes (2070/2099 minus present) of seasonal extreme precipitations (30-year return values, from GEV distribution). Units: mm/day
Two-way (self-) nesting between LMDZ-regional and LMDZ-global Global Regional
Global Regional Med Sea oceanic model (MED8) Global oceanic model (ORCA2) Schematic of the quartriple coupling in IPSL
SST from coupled model (MED8-LMDZr) Jan Apr Jul Oct
SST from coupled model (MED8-LMDZr-LMDZg) Jan Apr Jul Oct
Climatological SST (AMIP) JanApr JulOct
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.
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). An example of the two-way nesting atmospheric system
Difference (NatVeg – ObsVeg) Regional Global PrecipitationT2m PrecipitationT2m
An example of LMDZr and LMDZg two-way nesting system for climate change scenario (Yangtze River Basin)
Annual-mean rainfall (mm/d) (top), and its future variation (bottom: ) LMDZ-globalLMDZ-regionalLMDZ-sn
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.
Experimental design schematic CTRLNoSynExtra NoSynTropiNoSyn 6-hr varying BC climatological BC 6-hr varying BC climatological BC
January 2-m temperature (K) CTRL NoSynExtra - CTRL NoSynTropi - CTRLNoSyn - CTRL
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.
Perspectives more resolution at regional scale more interactivity in the system L.F. Richardsons view of numerical weather prediction (1920s) (painting: François Schuiten, 2000)