Newsletter No.5 January-1999@

"Toward the prediction of atmospheric composition change"

The Frontier Research System for Global Change
Program Director, Atmospheric Composition Research Program
(Research Center for Advanced Science and Technology, the University of Tokyo)
Hajime Akimoto

    Many recent global environmental issues,such as climate change resulting from global warming,ozone destruction, acid rain etc.are derived from atmospheric composition changes caused by the anthropogenic activity.It is absolutely necessary to elucidate the mechanisms of such changes and to make the precision of future predictions higher.
Moreover,the occurring atmospheric composition changes might generate as yet unknown global environmental concerns,and it is an important role of atmospheric composition change research to send out an early warning corresponding to these issues.

    At present,"The Atmospheric Composition Research Program"of the FRSGC mainly focuses the following research subjects.

(a)Transport and chemical-transport processes of reactive trace constituents in the East Asia and the West Pacific regions.
    The East Asia region,including northeastern and southeastern Asia is thought to be the region in which long term variation of the atmospheric composition will be the largest in the world in the earlier half of the next century due to its population increase and economic development.In the research we will elucidate the regional three-dimensional distributions and causes of long and short term variations of atmospheric composition of comparatively short-lived components such as tropospheric ozone,aerosols etc.,which affect global warming and climate changes on a regional scale.In addition,an increase of tropospheric ozone near the earth's surface may cause damages to forestry and farm products in these regions.Thus,urgent future prediction is necessary.

(b)Inter-agricultural-continental long-range transport mechanism
    In order to connect the results of regional researches to global environmental change,it is necessary to clarify inter-continental long-range transportation of trace constituents,e.g.,from Europe to Asia and from Asia to North America etc.,and their chemical-transformation processes.In this research,trans-Eurasian (from Europe to East Asia)long-range transport,which is the most important in the analysis of atmospheric component changes in East Asia,and long-range transport from East Asia to North America will be the focus.We will proceed with research integrating models and observational data.

(c)Variation and circulation of greenhouse gases
    In order to elucidate temporal and spatial variation mechanisms of the greenhouse gases,it is necessary for us to investigate detailed changes of intensities of sources and sinks including especially the biosphere,and to quantify circulation processes.For these purposes,we will analyse observational data related to isotopic composition of carbon and oxygen in carbon-dioxide,methane and carbon-monooxide.Data obtained on the ground,by airplanes,and research vessels will be analyzed using global three-dimensional models.
    "Atmospheric Chemistry",which is the scientific base for the Atmospheric Composition Research Program,is yet a young research field.This area is still also developing rapidly,and we welcome researchers in different fields,so long as they are interested in this area.
    We believe that this Program offers good research opportunities to young post-doctoral and pre-doctoral fellows,and hope that many geo-atmospheric chemists can apply their skills to problems of global scale through this Program .

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