Researchers FRONTIERNewsletter No.12 Oct.2000

Introduction of the researchers

Dr.Yih Dr.Hyungmoh Yih
Global Warming Research Program

I joined the Paleoclimate Research Division, Global Warming Research Program, about three months ago, when this summer season started. As the weather becomes hot, there are more copies of papers related to sea ice on my desk. My research interest is in the role of sea ice in global climate system.

My interest was motivated by the recognition of the importance of fresh water forcing to coastal ocean, while I did my dissertation research for the coastal circulation off Vancouver Island, Canada. The motivation was expedited by recognizing seasonal freezing and melting, as well as advance and retreat of sea ice around Antarctica. Fortunately I got an opportunity to pursue my interest by numerical modeling approach. I also had opportunities to do field work by using an icebreaker and to maintain a mooring of current-meters in the Weddell Sea. All of my previous experiences will definitely become composite to cover a field of research trials in the Global Warming Research Program. I am sure that we will take care of the new buds of research activities, and someday we will have a thanksgiving ceremony together.

I used to get off the train at Tamachi Station and pass by a sandwich shop. They have several sandwiches, all of them are named according to what is sandwiched. Sometimes I say to myself, "Sea ice is sandwiched in between atmosphere and ocean. We want to couple those two media through sea ice, in order to study the global climate system. Then the system came to be named sea ice climate system ..."

Dr.Wild Dr.James Oliver Wild
Atmospheric Composition Research Program

Ozone is an important constituent of the atmosphere, both in its own right as a greenhouse gas, and in an indirect role through control of OH and hence much of the oxidation of other gases in the troposphere. In the lower atmosphere it is a significant pollutant and as a strong oxidant it is damaging to most living things. Although there are a number of natural sources in the troposphere, comparison of recent measurements with those from last century suggest that these have been greatly increased by release of pollutants such as nitrogen oxides and hydrocarbons as a by-product of human development and industrialization. While most people are aware of smog in industrial, urban regions, fewer realise that far from being a local phenomenon it may affect large regions, and ultimately the balance of atmospheric oxidation over the whole globe. But how are we changing the oxidizing capacity of the atmosphere? How will this affect climate? What are the future impacts on urban air quality and on crop yields? The great variability of the sources and sinks of atmospheric oxidants and the complex coupling with meteorological processes require that we use high-resolution chemical transport models (CTM) to tackle these questions.

As part of the atmospheric composition program of FRSGC, I have been using a well-established CTM with a detailed treatment of tropospheric chemistry to demonstrate that short-lived chemical species may have significant indirect climate effects. I am also studying the long-range transport of ozone and its precursors between the major continental regions. There has been concern recently that rapid development, industrialization and vehicle ownership in China may offset projected air quality improvements in urban regions in the US; if these effects are significant as far away as North America, they may prove even more critical for Japan!

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