Spatial distribution of precipitation and heat fluxes over the North Western Pacific during the winter monsoon season
M. Yamamoto (1), K. Nakamura (2)
(1) Graduate School of Environmental Studies, Nagoya University
(2) Hydrospheric Atmospheric Research Center, Nagoya University
Ocean around Japan is well known as the precipitation zone of the winter monsoon. In this region, synoptic scale disturbances cause large changes of precipitation and cloud distributions. Especially, during the cold outbreaks, heat fluxes are important role to form the precipitation. Then, we investigated the spatial characteristics of precipitation and the heat fluxes. In this study, Tropical Rainfall Measuring Mission (TRMM) (Precipitation Radar (PR), TRMM Microwave Imager (TMI), and Visible and Infrared Scanner (VIRS)), the QuikScat SeaWinds, and the National Centers for Environmental Prediction-Department of Energy Atmospheric Model Intercomparison Project (NCEP-DOE AMIP-II) Reanalysis (NCEP2) dataset are used. The analyzed area is 25°–40°N, 115°–180°E.
During the cold outbreak, the height of precipitation reaches around 2 km and precipitation dominates the shallow, isolated, and weak (~20 dBZ). Around the extratropical cyclones and fronts, the height of precipitation reaches around 3 km and precipitation is relatively broad and weak. The solid precipitation over the freezing height is a few.
The heat fluxes are calculated using the simple bulk formulas. The cold outbreaks make the sum of sensible and latent heat fluxes possible to reach to about 800 W m-2. The sensible heat flux over the Japan Sea is similar to that over the coastal region in the Pacific Ocean. The contribution of the latent heat flux over the Pacific Ocean is larger than that over the Japan Sea. This is because the difference of the specific humidity between the sea surface and atmosphere over the Pacific Ocean is larger than that over the Japan Sea due to the Kuroshio Current. On the contrary, the region around the extratropical cyclones and fronts, the sensible and the latent heat fluxes are very small. This is because the differences of temperature and specific humidity between the sea surface and the atmosphere are small.
Submittal Information
Name :
Date :
Munehisa Yamamoto
30-Jul-04-10:09:09
Organization :
Theme :
Graduate School of Environmental Studies, Nagoya University
Theme 8
Address :
Presentation :
Hydrospheric Atmospheric Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, JAPAN