Chemistry-Climate Interaction Studies in Japan

Hajime Akimoto

Atmospheric Composition Research Program

Frontier Research System for Global Change

Chemistry Climate Interactions Workshop, Santa Fe, February 10-12, 2003

Only one AGCM-Based Chemical Transport Model

“CHASER” = CCSR/NIES AGCM + Tropospheric Chemistry(gas Phase)

Development of CHASER

CCSR: Center for Climate System Research, UT 　 RCAST: Research Center for Advanced Science and Technology, UT 　 FRSGC: Frontier Research System for Global Change

Model Description and validation

Sudo, K., M. Takahashi, J. Kurokawa, and H. Akimoto, J. Geophys., Res., 107 (D17), 10.1029/2001JD001

113, 2002. Sudo, K., M. Takahashi, and H. Akimoto,

J. Geophys., Res., 107 (D17), 10.1029/2001JD001114, 2002.

Present Status of Chemistry-Climate Research in Japan

Present Status of CHASER

Horizontal resolution: T21 (5.6 ゜ ) / T42 (2.8 ゜ )

Vertical resolution: 32 layer (Upper boundary ca. 35 km)

Advection Scheme: Flux-Form Semi-Lagransian [Lin and Rood, 1996]

Radiation Scheme: Discrete Ordinate Method + k-distribution[Nakajima et al., 1996]

Chemistry Scheme: Tropospheric chemistry up to ca. 20 km Chemical Species: 51 Gas phase reactions: 94 Photolytic reactions: 24 Liquid phase reactions: 4

Heterogeneous reactions: 1

Radiative forcing (W m-2) due to tropospheric ozone increase calculated by CHASER （ preindustrial present-day ）

0.3820.5920.487LW＋SW

0.0630.1070.085SW

0.3190.4850.402LW

SHNHGlobal

LW＋ SW　 total ozone forcing

DJF

JJA

Tropospheric ozone radiative forcing W m-

2 (at tropopause, in annual mean)

Normalized radiative forcing = 0.047 W m-2 DU-1

Tropospheric ozone increase

197 TgO3 (preindustrial) ↓ +10.4 DU (+58%)311 TgO3 (present-day)

Radiative forcing (W m-2) due to tropospheric ozone increase （ preindustrial present-day ）

0 0.5 1 1.5

Trop.O3

CH4

CO2Hauglustaine et al., 1994

Marenco et al., 1994

Chalita et al., 1995

Forster et al., 1996

Berntsen et al., 1997

Haywood et al., 1998

Mickley et al., 1999

Roelofs, 1999

Roelofs and Lelieveld,2000This work

(W m-2)

This work (0.49 W m-2)

Global mean radiative forcing

SRES-A2 Emission Scenario

Future prediction experiment of tropospheric ozone

Change of Tropospheric Ozone Production Rate

SRES-A2 1990 2050 2100

The meteorological effect of El Nino (1997) on the tropospheric chemistry

Difference (anomaly) : October 1997 minus October 1996

[Sudo and Takahashi, 2001]

Changes over 10oS-10oN

(Lon.-Alt.)

Ozone (ppbv)

Convective mass flux & up/downward motions

Specific humidity (g/kg)

Ozone chemical lifetime (%)

Oct. 1997 minus Oct. 1996

Future Plan using CHASER

Model Development

Inclusion of aerosol model

Integration of stratospheric chemistry model

Model Simulation

Past simulation and Future prediction of air quality based on new emission models

Global warming Prediction using fully-coupled CHASER/AGCM

Concept of Integrated Model Development at FRSGC

Climate(CCSR/NIES AGCM 5.7)

Chemistry(CHASER)

Aerosol(SPRINTARS)

Land Surface(MATSIRO,Sym-CYCLE)

Ocean(an NPZD-type model)

transport

radiationcloud distribution

transport

radiation

production

heterogeneous reaction

DMS NMHCsCO2Sea Salt dust, OC

SST

mineral