asian perspective of the cryosphere-atmosphere feedbacks...inca (interaction between chemistry and...
TRANSCRIPT
PKU-LSCE meeting, 15 FEB 2011
Yves Balkanski,
LSCE, CEA-CNRS-UVSQ
Asian perspective of the cryosphere-atmosphere feedbacks
PKU-LSCE meeting, 15 FEB 2011
Motivation and main objectives
The study of the role of the strongly absorbing black carbon and of dust How aerosols influence the onset and the position of the monsoon? Consequences of changes in snow albedo for the climate in the region
(Bajracharya et al 2007) PKU-LSCE meeting, 15 FEB 2011
PKU-LSCE meeting, 15 FEB 2011
LMDz General circulation model fully coupled to INCA (INteraction between Chemistry and Aerosols) Model resolution: 144x142xL19 or 144x142xL39
CHEMISTRY: Tropospheric chemistry representing methane oxidation (45 tracers et 100 reactions)
AEROSOLS: Mineral aerosols, Seasalt, sulphates, black carbon, primary and secondary organics
Modélisation globale Modélisation globale tri tri - - dimensionnelle dimensionnelle (3D) de la (3D) de la chimie chimie
μ i ( x o , t o )
μ i ( x, t )
transport, transport, photochemistry, … photochemistry, …
Resolution used Resolution used in in LMDz LMDz - - INCA INCA 2.25 2.25 ° ° longitude longitude × × 1.8 1.8 ° ° longitude longitude 50 vertical 50 vertical levels levels Total of 784,000 Total of 784,000 grid grid points points
Time Time step step 30 min 30 min Number Number of of species species : 10 : 10 - - 100 100 CPU for 1 CPU for 1 year year simulation : 300 simulation : 300 hours hours
L P E Conv Diff v t
- + + + + ∇ ⋅ - = ∂ ∂
µ µ
PKU-LSCE meeting, 15 FEB 2011
PKU-LSCE meeting, 15 FEB 2011
Comparaison with aerosol optical depth
MODELE
POLDER instrument
0.00
0.10
0.20
0.30
0.40
0.00
0.10
0.20
0.30
0.40
PKU-LSCE meeting, 15 FEB 2011
PKU-LSCE meeting, 15 FEB 2011
2
3
4
5
1
0 80°S
40°N
40°S
80°N
0°
100°E 0° 100°W
Différence du contenu en eau liquide (105 kg/kg):
Différence de concentration d’aérosols 2000 -1750 (µg/m3)
80°S
40°N
40°S
80°N
0°
100°E 0° 100°W
1.2
1.8
2.4
3
.6
- .3
.3
.9
1.5
2.1
2.7
0
Moyenne globale = - 0.46 W/m²
- 2
- .5
5
1
-10 - 5
- 1
10
2
.5
.2 - .2
80°S
40°N
40°S
80°N
0°
100°E 0° 100°W
IPCC AR4: - 0.7 [-1.8 to -0.3 ] W/m²
Forçage radiatif (W/m²)
PKU-LSCE meeting, 15 FEB 2011
Incoming solar
radiation Incoming IR
radiation
Sensible / latent heat fluxes
- conduction - melting / freezing - percolation - settling - metamorphism
Wind
rain snow
SNOWPACK
ATMOSPHERE
GROUND
melting run-off
geothermal heat flux
++
⋅⋅
+
++
⋅⋅
+
incoming radiation
temperature BC content
snow type
also: density specific surface area diffusion / advection
SNOWPACK MODELING USING CROCUS with INPUT from
observations and / or regional / global models
Work package 4: MODELLING THE INTERACTION BETWEEN SNOWPACK, RADIATION, AND THE ABSORBING MATERIAL DEPOSITED IN THE SNOW
albedo
BC deposition
Local 1D modeling of optical snowpack properties for different conditions / altitudes: • glaciers • seasonal snowpack
Quantification of BC impact in snow on • melting rates and days • contribution of the snow melting to the total run-off • sensitivities to future changes in temperature and atmospheric BC
radiation
Implementation of the effect of BC on snow albedo and radiation transfer in the snowpack
PKU-LSCE meeting, 15 FEB 2011
8 5 1 .5 .1 .05 -.05
-.1 -.5 -1 -5 -8
PKU-LSCE meeting, 15 FEB 2011
We have coupled a chemistry-aerosol module to the Earth System Model from IPSL
It allows to study large regions with a zoom and consider how chemically driven processes affect climate (and vice-versa)
A study to understand the effects of aerosols on the monsoon and on the hydrological cycle is underway
We will specifically address the effect of a change in albedo due to black carbon and dust deposition
PKU-LSCE meeting, 15 FEB 2011
(1950) ,
Nainital NTL, 1950m
Trivandrum TVM 3m asl
PKU-LSCE meeting, 15 FEB 2011
Menon et al., 2009
BC concentrations (µg.m-3)
PKU-LSCE meeting, 15 FEB 2011
Need to resolve BC concentration in the region
Improve the representation of snow/albedo in the models
Diagnose the monsoon (see Marzin and Braconnot 2009) to better represent the general flow, onset and precipitation in the model
PKU-LSCE meeting, 15 FEB 2011
LMDz-ORCHIDEE-INCA (SST fixed)
Computes the aerosol concentrations and deposition: BC, POM, SO4, dust and seasalts
Represents the change in albedo
Coupled IPSL model Simulates changes in the intensity, onset
phases and extent of the monsoon
PKU-LSCE meeting, 15 FEB 2011