HR: 1340h
AN: H33C-1447    [Abstracts]
TI: Seasonality and Remoteness/Locality of Land-Atmosphere Coupling Strength
AU: * Yamada, T J
EM: tyamada@gmao.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center/Goddard Earth Sciences and Technology Center/Research Fellow of the Japan Society for the Promotion of Science (PD), Code 610.1 NASA Goddard Space Flight Center, Greenbelt, MD 20771, United States
AU: Kanae, S
EM: kanae@iis.u-tokyo.ac.jp
AF: Institute of Industrial Science, The University of Tokyo, Institute of Industrial Science, The University of Tokyo, 4-6-1, Komaba, Meguro, Tokyo, 153-8505, Japan
AU: Oki, T
EM: taikan@iis.u-tokyo.ac.jp
AF: Institute of Industrial Science, The University of Tokyo, Institute of Industrial Science, The University of Tokyo, 4-6-1, Komaba, Meguro, Tokyo, 153-8505, Japan
AU: Koster, R D
EM: randal.d.koster@nasa.gov
AF: NASA Goddard Space Flight Center, Code 610.1 NASA Goddard Space Flight Center, Greenbelt, MD 20771, United States
AB: In this study, we estimate the seasonal variation of land-atmosphere coupling strength using an extended series of atmospheric general circulation model (AGCM) simulations. In the western Sahel of Africa, strong coupling strength for precipitation is found in April and May, just prior to and at the beginning of the monsoon season. At this time, unstable conditions in the lower level of troposphere, as induced by local land state, allow heat and water fluxes from the land surface to influence the variability of convective precipitation - and thus the timing of monsoon onset. We also investigate the potentially non-local nature of land-atmosphere coupling strength. Our AGCM experiments show that the prescription of land surface states in the Tibetan Plateau in June has a strong remote impact on the geopotential height variability at 500hPa height over eastern China and Japan, where strong westerly wind fields are formed by subtropical and polar jets. A remote impact is also seen in the 850 hPa height fields there. The geographical distribution of Tibetan Plateau impact corresponds to the Meiyu/Baiu fronts in June, which suggests that the prescription of the Tibetan Plateau's land surface states may help guide East Asian summer monsoon activity.
DE: 1818 Evapotranspiration
DE: 1840 Hydrometeorology
DE: 1843 Land/atmosphere interactions (1218, 1631, 3322)
DE: 1878 Water/energy interactions (0495)
SC: Hydrology [H]
MN: 2007 Fall Meeting