Dr. Sudo of the Atmospheric Composition Research Program received the
Yamamoto -Syono Award for Outstanding Papers from the Meteorological Society of Japan
- FRCGC Researchers Receive the Prize for Four Years in a Row-

Sudo Receiving the Award at the fall meeting of the Meteorological Society's meeting
Dr. Sudo of the Atmospheric Composition Research Program, Frontier Research Center for Global Change, received the Yamamoto-Syono Award for Outstanding Papers from the Meteorological Society of Japan. It is awarded every year to one or two recently published papers by young scientists below thirty-five years old. Following Dr.Yoichi Tanimoto and Dr. Kotaro Takaya of Climate Variations Research Program, and Dr. Takeshi Enomoto of Integrated Modeling Research Program (currently at Earth Simulator Center), Sudo's honor is the fourth to receive this prize by FRCGC researchers since 2001 in a row. The following two titles are the winning papers appeared in the September and November 2002 issues of Journal of Geophysical Research;

"CHASER: A global chemical model of the troposphere 1. Model description" (J. Geophys. Res., 107, 10.1029/2001JD001113, 2002),
"CHASER: A global chemical model of the troposphere 2. Model results and
evaluation" (J. Geophys. Res., 107, 10.1029/2001JD001114, 2002)

In the above referenced papers, Sudo describes and evaluates in detail the chemistry coupled climate model CHASER which he newly developed during his doctoral studies in Center for Climate System Research (CCSR), university of Tokyo. To assess future changes in global climate and atmospheric environment, atmospheric chemistry and aerosols should be taken into account as well as dynamical and physical processes in the atmosphere. Ozone(O3) in the troposphere, a significant pollutant and greenhouse gas, has a critical importance for tropospheric photochemistry to activate chemical reactions and control concentrations of other pollutants and climatically important species like methane (CH4), halofluorocarbons (HFCs), and sulfate (SO4--). Sudo has developed a chemistry coupled climate model named CHASER, which includes detailed tropospheric chemistry involving ozone as well as stratospheric chemistry. The CHASER model, developed in the framework of the CCSR/NIES/FRCGC climate model, is aimed to investigate global tropospheric ozone distribution and related chemistry, and their impacts on climate. CHASER considers detailed photochemical reactions, natural and anthropogenic emissions of precursors (NOx,CO,VOCs,SO2) including NOx formation by lightning, transport, surface dry deposition, and wet deposition associated with precipitation. In the detailed evaluation of the model results, the CHASER calculations show excellent agreement with observations in most cases for important trace gases such as CO, VOCs, NOx species, HOx and related species as well as for ozone. Using CHASER, Sudo also attempted to calculate global budget of tropospheric ozone and quantified the ozone flux from the stratosphere and photochemical production of ozone within the troposphere individually. CHASER, used in the FRCGC/CCSR Global Chemical Weather Forecast System, also contributes to daily forecast of global air pollution.

The CHASER model, based on a climate model, can be expected to contribute much to investigation of chemistry/climate interaction. Sudo actually has started several key experiments to assess the impacts of ENSO and future climate change (warming) on ozone distribution and related chemical processes. His experiments suggest that changes in atmospheric circulation, temperature, and water vapor can modulate significantly distribution and temporal evolution of ozone, methane, and aerosols.

Sudo says that he is developing prediction of climate and atmospheric environment in the context of chemistry/aerosol/climate interaction. The CHASER model is also expected to play an important role in the FRCGC integrated Earth system modeling with the Earth Simulator which is part of the MEXT project.