Grant-in-Aid for Scientific Research on Priority Areas (A)
|Research Institution||The University of Tokyo|
KIMOTO Masahide Center for Climate System Research, University of Tokyo, Associate Professor, 気候システム研究センター, 助教授 (30262166)
SATOMURA Takehiko Department of Physics, Faculty of Science, Kyoto University, Associate Professor, 大学院・理学研究科, 助教授 (20273435)
RIKU Binkou Nagaoka University of Technology, Associate Professor, 工学部, 助教授 (80240406)
WAKATA Yoshinobu Research Institute for Applied Mechanics, Kyushu University, Professor, 応用力学研究所, 教授 (90201871)
IKEBUCHI Shuichi Disaster Prevention Research Institute, Kyoto University, Professor, 防災研究所, 教授 (20026181)
SUMI Akimasa Center for Climate System Research, University of Tokyo, Professor, 気候システム研究センター, 教授 (10179294)
|Project Fiscal Year
1996 – 1998
Completed(Fiscal Year 1999)
|Budget Amount *help
¥48,000,000 (Direct Cost : ¥48,000,000)
Fiscal Year 1998 : ¥20,000,000 (Direct Cost : ¥20,000,000)
Fiscal Year 1997 : ¥13,000,000 (Direct Cost : ¥13,000,000)
Fiscal Year 1996 : ¥15,000,000 (Direct Cost : ¥15,000,000)
|Keywords||satellite data / climate model / four-dimensional data assimiation / 衛星データ / 気候モデル / 4次元データ同化|
Researches have been conducted on utilization of satellite data, on the development of numerical models and data assimilation methods for various climate subsystems, and on a better description of continental-scale water and energy flows. Major results are summarized as follows.
-Algorithm for building the global river routine model has been automated, enabling flexible setup of the model. The model performance has been verified by river outflow data.
-A land-surface model capable of computing CO2 fluxes has been coupled to an atmospheric general circulation model. The seasonal cycle of atmospheric CO2 has been successfully reproduced.
-A data assimilation scheme using Kalman filtering has been developed for a coupled vegetation-land surface model.
-A numerical experiment has been conducted to assess impact of actual and potential vegetation distributions to climate, the vegetation data sets being produced by the vegetation subgroup of this research project. The results are sensitive to al
bedo, i.e., reflectance of the vegetation for solar insolation. It has been recognized that for a more credible assessment of the vegetation-atmosphere interactions, further sensitivity tests are necessary for land hydrology and convection schemes and horizontal resolution of the atmospheric model.
-Impact of micro wave imager data on atmospheric data assimilation has been assessed. It has been found that improvements in water vapor fields contributes significantly to short-range precipitation forecasts.
-Results of a cloud-resolving model has been utilized to validate parameterization schemes of convective clouds used in global circulation models. It is found that better representations of vertical redistribution of water vapor are demanded.
-A 1-degree-by-1-degree gridded data set of monthly global ocean subsurface temperature (0-500m depths) between the years 1950 and 1997 has been produced using a three-dimensional variational analysis scheme with an error estimation algorithm. The data set is valuable for analyses of decadal climate variability.
-A system for assimilating upper-ocean subsurface temperature and satellite altimeter data into a general circulation model has been developed. The satellite data contributes significantly to the depiction of subtropical Rossby wave activities.
-The continental-scale water and energy budgets have been re-evaluated by combining satellite estimates and atmospheric reanalysis data sets. Reduction in erroneous residuals has been found, thanks to increased accuracy in the reanalysis data sets. For a more accurate estimate, better understandings of cloud radiative effects, water circulations, and so on are necessary.
-The role of ocean-atmosphere coupling in the formation of tropical climate has been clarified. Less