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Millenium simulations at IPSL. THOR: C. Frankignoul , G. Gastineau , C. Marini, J. Mignot Escarsel : M. Khodri , J. Servonnat , P. Yiou. THOR CT1 meeting, Bergen, Oct 1-2 2009. The IPSL-CM4 coupled model. LMDZ : atmospheric physics and dynamics
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Millenium simulations at IPSL THOR: C. Frankignoul, G. Gastineau, C. Marini, J. Mignot Escarsel: M. Khodri, J. Servonnat, P. Yiou THOR CT1 meeting, Bergen, Oct 1-2 2009
The IPSL-CM4 coupled model LMDZ: atmospheric physics and dynamics horizontal resolution 96x72, 19 vertical layers ORCHIDEE: land surface OASIS OPA: ocean dynamics based on a 2 degrees Mercator mesh (orca), 31 vertical levels LIM: sea-ice dynamics and thermodynamics Marti et al 2008 http://mc2.ipsl.jussieu.fr/simules.html, http://igcmg.ipsl.jussieu.fr/Doc/IPSLCM4/
The IPSL-CM4 coupled model • Simulations: • CTRL1000 years control simulation, preindustrial GHGs and tropospheric aerosols concentrations • SOL 950 years (1001-1950) years simulation including solar forcing, historical GHGs (Joos et al. 2008) and preindustrial tropospheric aerosols concentrations • SOLVOL 300 years (starting yr 850) simulation including solar +volcanic forcing
The solar forcing 1367 TSI Crowley (2000), W/m-2 1365 SOL 1363 (a) 1400 1600 1800 2000 1000 1200 Calendar time Amman et al. 2007: -0.25% TSI at the Maunder minimum More recent estimates: -0.1 % at the Maunder minimum SOLVOL Krivova , pers. com. 2009
SOL – northern hemisphere temperatures Good global agreement, Cold « bias » (Missing volcanoes, which would have decreased the warming between 1700-1900.) Correlation with TSI: 0.74 Reconstructions overlapOsborn and Briffa, IPCC AR4, Solomon et al. 2007 Servonnat et al., in prep.
SOL – northern hemisphere temperatures Preind. CTRL (a) Mann et al 2008 EIV Comparison with four individual reconstructions (b) Northern Hemisphere surface temperature anomalies (°C ref 1750-1850) Moberg et al 2005 (c) Crowley & Lowery 2000 (d) Ammann & Wahl 2007 (e) Servonnat et al., in prep.
SOL – regression of temperature on TSI • 1000-1800 annual mean • Max sensitivity with 15 yrs lag: 0.109°C/W.m-2 • sensitivity over sea ice > over land > over ocean Lag 15 yrs Servonnat et al., in prep.
80°N 80°N 80°N 80°N 40°N 40°N 40°N 40°N Eq Eq Eq Eq 40°S 40°S 40°S 40°S 80°S 80°S 80°S 80°S 3 2.6 2.2 1.8 1.4 0° 0° 0° 0° 0° 0° 100°E 100°E 100°E 100°E 100°E 100°E 100°W 100°W 100°W 100°W 100°W 100°W 1 0.6 0.2 - 0.2 - 0.6 - 1 - 1.4 - 1.8 - 2.2 - 2.6 - 3 CTRL/SOL surface temperature variability Summer Annual mean Winter + 1 SD CTRL (c) (e) (a) - 1 SD (d) (f) (b) Warm Period (1230-1280 AD) (i) (k) SOL Cold period (1684-1734 AD) (h) (j) (l) Servonnat et al., in prep.
80°N 80°N 80°N 80°N 40°N 40°N 40°N 40°N Eq Eq Eq Eq 40°S 40°S 40°S 40°S 80°S 80°S 80°S 80°S 3 2.6 2.2 1.8 1.4 0° 0° 0° 0° 0° 0° 100°E 100°E 100°E 100°E 100°E 100°E 100°W 100°W 100°W 100°W 100°W 100°W 1 0.6 0.2 - 0.2 - 0.6 - 1 - 1.4 - 1.8 - 2.2 - 2.6 - 3 Global Land Ocean Global Land Ocean Global Land Ocean Global Land Ocean Global Land Ocean Global Land Ocean = 70% = 70% = 70% = 73% = 80% = 70% = 75% = 78% = 73% = 71% = 73% = 71% = 76% = 83% = 73% = 67% = 57% = 72% CTRL/SOL surface temperature variability Summer Annual mean Winter + 1 SD CTRL (c) (e) (a) Annual mean Summer Winter - 1 SD WP (d) (f) (b) -1SD/+1SD Warm Period (1230-1280 AD) CP SOL (i) (k) SOL Cold period (1684-1734 AD) (h) (j) (l) Servonnat et al., in prep.
SOLVOL – sensitivity of the atmospheric model to volcanic forcing Anomalous response of LMDZ to Mt Pinatubo eruption (DJF 1991-1992) a) LMDZ b) Observations (Robock, 2000) Temperature in the low troposphere 500mb geopotential Khodri, pers. com.
SOLVOL – volcanic forcing in the IPSL model • Sulfate aerosol in the stratosphere • Volcanic eruption with a VEI>4 • Essentially tropical eruptions • Mie code to compute the simple diffusion albedo and asymetry factor for the sulfate stratospheric aerosol in water phase • Implementation of the optic thickness on the 2 layers above the tropopause Optic thickness of the volcanic aerosols for the Mt Pinatubo eruptions (1991-1992) altitude latitude DJF 1991-1992 months latitude Khodri, pers. com.
Atlantic thermohaline circulation CTRL SOL SOLVOL
Atlantic thermohaline circulation CTRL SOL SOLVOL MSF average CTRL
North Atlantic deep convection Maximum mixed layer depth in March CTRL
Horizontal circulation in the northern North Atlantic in winter CTRL
Plans • Use of IPSL_CM5 model: ORCA2 x LMDZ (96x95x39) • run should start before end 2009 • Only SOLVOL experiment? • forcings? • - THC variability on decadal to centennial timescale – process studies • Ocean-atmosphere feedback • internal vs externally forced variability
Implémentation de l’impact radiatif des aérosols volcanique dans MDZ • Code de Mie: • Calcul de l’albédo de simple diffusion (cg) et le facteur d’asymétrie (piz) pour les aérosols stratosphériques sulfatés en phase aqueuse (forme binaire H2SOA/H2O: 75%/25%) • El Chichon + Pinatubo (SO4 droplet): • # R : rayon modal en nm : 500.0 • # Sigma : largeur de distribution: 1.30 • # w1 w2 : albedo de simple diffusion sur les 2 bandes du visible : 1.000 0.995 • # g1 g2 : paramËtre d'assymÈtrie sur les 2 bandes du visible : 0.7079 0.7548 • Implémentation de l’épaisseur optique (Tau) sur les 2 couches atmosphériques au dessus de la tropopause Epaisseur optique des aérosols volcanique Pour l’éruption du Mt Pinatubo (1991-1992) altitude latitude DJF 1991-1992 mois latitude Khodri, pers. com.
Volcanic Explosive Index, VEI (Newhall y Self, 1982) Volcanic eruptions with stratospheric impact : VEI > 4 Khodri, pers. com.
Mixed layer depth in the North Atlantic Monthly mean maximum De Boyer Montégut et al. 2005 Standard deviation of the March monthly values
Annual mean Atlantic meridional overturning circulation Time series of the AMOC maximum
Temporal characteristics of the maximum of the annual mean AMOC
Atlantic annual mean SST and SSS Reynolds Reverdin
ENSO in IPSL-CM4 64% First EOF of tropical Pacific SST Regression of the SLP on the corresponding principal component
65,5 % ENSO Model 64 % Observations (Reynolds and NCEP)