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