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

OPA: ocean dynamics based on a 2 degrees Mercator mesh (orca), 31 vertical levels

LIM: sea-ice dynamics

and thermodynamics

ORCHIDEE: land surface

OASIS

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

TS

I C

row

ley

(2

00

0),

W/m

-2

(a)13

63

13

65

13

67

The solar forcing

1000 1200 1600 1800 20001400

Calendar time

SOL

SOLVOL Krivova , pers. com. 2009

Amman et al. 2007: -0.25% TSI at the Maunder minimum

More recent estimates: -0.1 % at the Maunder minimum

SOL – northern hemisphere temperatures

Reconstructions overlap Osborn and Briffa, IPCC AR4, Solomon et al. 2007

Good global agreement,

Cold « bias »(Missing volcanoes, which would have decreased the warming between 1700-1900.)

Correlation with TSI: 0.74

Servonnat et al., in prep.

No

rth

ern

He

mis

ph

ere

su

rfa

ce t

em

pe

ratu

re a

no

ma

lies

(°C

re

f 1

75

0-1

85

0)

Prein

d.

CT

RL

Ma

nn

et a

l 2

008

EIV

Mo

be

rg e

t a

l 200

5C

row

ley &

L

ow

ery 20

00

Am

man

n &

W

ahl 2

007

(a)

(e)

(d)

(c)

(b)

SOL – northernhemisphere temperatures

Comparison with four individual reconstructions

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

Servonnat et al., in prep.

Lag 15 yrs

CTRL/SOL surface temperature variability

CTRL

SOL

80°N

40°N

Eq

40°S

80°S

100°W 100°E0° 100°W 100°E0° 100°W 100°E0°

100°W 100°E0° 100°W 100°E0° 100°W 100°E0°

80°N

40°N

Eq

40°S

80°S

Co

ld p

erio

d

(168

4-17

34 A

D)

War

m P

erio

d

(123

0-12

80 A

D)

- 1

SD

+ 1

SD

Annual mean Summer Winter

(a)

(b)

(c)

(d)

(e)

(f)

(k)

(l)

(i)

(j)(h)

80°N

40°N

Eq

40°S

80°S

80°N

40°N

Eq

40°S

80°S

0.20.611.41.82.22.63

- 0.2- 0.6- 1- 1.4- 1.8- 2.2- 2.6- 3

Servonnat et al., in prep.

CTRL/SOL surface temperature variability

CTRL

SOL

80°N

40°N

Eq

40°S

80°S

100°W 100°E0° 100°W 100°E0° 100°W 100°E0°

100°W 100°E0° 100°W 100°E0° 100°W 100°E0°

80°N

40°N

Eq

40°S

80°S

Co

ld p

erio

d

(168

4-17

34 A

D)

War

m P

erio

d

(123

0-12

80 A

D)

- 1

SD

+ 1

SD

Annual mean Summer Winter

(a)

(b)

(c)

(d)

(e)

(f)

(k)

(l)

(i)

(j)(h)

80°N

40°N

Eq

40°S

80°S

80°N

40°N

Eq

40°S

80°S

0.20.611.41.82.22.63

- 0.2- 0.6- 1- 1.4- 1.8- 2.2- 2.6- 3

Servonnat et al., in prep.

Global

Land

Ocean

= 75%

= 78%

= 73%

Global

Land

Ocean

= 71%

= 73%

= 71%

Global

Land

Ocean

= 76%

= 83%

= 73%

Global

Land

Ocean

= 73%

= 80%

= 70%

Global

Land

Ocean

= 67%

= 57%

= 72%

Global

Land

Ocean

= 70%

= 70%

= 70%

CP

WP

Annual mean

Summer Winter

-1S

D/+

1S

D

SOL

SOLVOL – sensitivity of the atmospheric model to volcanic forcing

b) Observations (Robock, 2000)

Anomalous response of LMDZ to Mt Pinatubo eruption (DJF 1991-1992)

Temperature in the low troposphere

500mb geopotential

a) LMDZ

Khodri, pers. com.

SOLVOL – volcanic forcing in the IPSL model• Sulfate aerosol in the stratosphere• Volcanic eruption with a VEI>4• Essentially tropical eruptions

Optic thickness of the volcanic aerosols for the Mt Pinatubo eruptions (1991-1992)

months latitude

latit

ude

altit

ude

DJF 1991-1992

• 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

Khodri, pers. com.

Atlantic thermohaline circulation

CTRLSOLSOLVOL

Atlantic thermohaline circulation

MSF average CTRL

CTRLSOLSOLVOL

North Atlantic deep convection

Maximum mixed layer depth in March

CTRL

Barotropic streamfunction

CTRL

Horizontal circulation in the North Atlantic

CTRL

Horizontal circulation in the North Atlantic in winter

CTRL

Horizontal circulation in the northern North Atlantic

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 volcaniquePour l’éruption du Mt Pinatubo (1991-1992)

mois latitude

latit

ude

altit

ude

DJF 1991-1992

Khodri, pers. com.

Volcanic Explosive Index, VEI (Newhall y Self, 1982)

  VEI HAUTEUR DU

PANACHEVOLUME D’ÉJECTION

  CLASSIFICATIONEXEMPLE

 0  <100 m  1000s m3  Hawaiano  Kilauea

 1 100-1000 m  10000s m3  Hawaiano/Estromboliano

 Stromboli

 2  1-5 km  1000000s m3  Estromboliano/

Vulcaniano  Galeras (1992)

 3  3-15 km  10000000 m3  Vulcaniano Ruiz (1985)

 4  10-25 km  100000000s m3  Vulcaniano/Plineano  Galunggung

(1982)

 5  >25 km  1 km3  Plineano St. Helens (1980)

 6  >25 km  10s km3  Plineano/Ultra-Plineano  Krakatau (1883)

 7  >25 km  100s km3  Ultra-Plineano  Tambora (1815)

 8  >25 km  1000s km3  Ultra-Plineano  Toba (74 ka)

Volcanic eruptions with stratospheric impact : VEI > 4

Khodri, pers. com.

Mixed layer depth in the North Atlantic

Monthly mean maximum

Standard deviation of the March monthly values

De Boyer Montégut et al. 2005

Annual mean Atlantic meridional overturning circulation

Time series of the AMOC maximum

Temporal characteristics of the maximum of the annual mean AMOC

Leading mode of SLP variability over the North Atlantic

2nd EOF of SLP over the North Atlantic

Atlantic annual mean SST and SSS

Reynolds

Reverdin

ENSO in IPSL-CM4

First EOF of tropical Pacific SST

Regression of the SLP on the corresponding principal component

64%

ENSO

Model

Observations (Reynolds and NCEP)

65,5 %

64 %