Newsletter No.8 Ocotober-1999

After I left Hokkaido in the spring of 1997, where I lived quite a while, and worked for a half a year at the University of Tokyo as a post- doctor, I joined the Climate Variations Research Program in October 1997, the same time that the FRSGC started. My specialization is meteorology and I have special interest in the variability of the atmospheric circulation at mid and high- latitudes during the winter season. I also have interest in the response of the atmospheric field to the variability of oceans and sea ice. In my doctoral dissertation at Hokkaido University, I was able to show that variations of sea ice in the Sea of Okhotsk have an influence on the atmospheric circulation in the far North America by a numerical experiment and a data analysis. 　Now at the FRSGC, I have two themes to solve: one is, by using objective analysis data, investigation of a dynamic seesaw mechanism between the Aleutian low and the Icelandic low, and it's effect on the atmospheric circulation fields in the Northern Hemisphere by the atmospheric bridge between the North Pacific and the North Atlantic. It has now become clear that this seesaw has a substantial relation to spatial pattern formation of the "Arctic Oscillation (AO)"recently known as a one of dominant variability in the extra tropical in the Northern Hemisphere circulation during winter. 　Another theme is mainly related to numerical experiments. I have already obtained results that shows that variability of sea- surface temperature fields over the sub polar front in the North Pacific in winter could have a significant influence on the atmospheric circulation frontal in the Northern Hemisphere. Of course, these two themes are not independent. I am convinced that in future these two will have a tight relation with each other. I will do my best to elucidate the atmospheric circulation in the Northern Hemisphere and the variability of the North Pacific and North Atlantic, incorporating them comprehensively into an atmosphere-oceans coupled system. Homepage http://w3.frontier.esto.or.jp/d1/meiji/index-e.html 水循環予測研究領域 陸 旻皎 Hydrological Cycle Research Program Dr.Minjiao Lu 　98年8月1日に水循環予測研究領域に赴任してきました。陸面水循環過程グループに所属し、陸面水文モデルの開発に取り組んでいます。それまでは長岡技術科学大学での教育研究に従事していました。 　ご存じのように，大気と海洋に比べて、陸面は極めて不均一です。陸面水文過程もそれゆえの多様性をもち、私の今までの研究は流域を細かく分割し、それらを忠実に表現する分布型水文モデルを開発し、降水から河川流量までの水循環を表現し、理解することに重点を置いてきました。一方では、気候システムにおける陸面水文過程の重要性も顕在化してきており（他が進んだためボトルネックになってきたともいえます）そのモデリングには陸面不均一性を考慮したパラメタリゼーションが不可欠です。個人的には、大気モデルと陸面モデルのカップリング、サブグリッドスケールの陸面不均一性の影響評価とそのパラメタリゼーション、そして各グリッドからの流出の河口までの運動を表現する河道追跡モデルの開発をフロンティアでの仕事として研究を進めて行きたいと考えています。 　良いモデルは様々な自然条件下でのプロセス研究の集大成であれば、各サブモデルのハーモニーでもあります。皆さんとともに、ハーモニーを求めていきたいと思います。 　I joined in the Hydrological Cycle Research Program on August 1, 1998. I belong to the Land Surface Hydrological Cycle Process Group, and work on development of land surface hydrological model. Before entering the FRSGC, I worked at Nagaoka University of Technology, being engaged in education and research there. 　As a well known fact, land surface is much more heterogeneous than the atmosphere and the oceans. Therefore, the land surface hydrological processes also have the same kind of diversity. My research works up to now have focused on the development of high resolution distributed hydrological model, on the understanding and representation of water cycle from precipitation to river flow. On the other hand, the importance of land surface hydrology in climate system has been realized (in other words, land surface hydrology becomes a bottle- neck after the progresses in other research areas). In order to take into account the heterogeneity of land surface in climate research, parameterization is indispensable. At the FRSGC, I shall work on evaluation of sub- grid heterogeneity of the land surface and its parameterization, coupling of atmospheric model and hydrological model, development of routing model for continental scale basins. 　Good model integrates the results of process study under various natural conditions, also produces harmony among the sub- models. It's my pleasure to seek out a harmonic model with colleagues in the FRSGC.