Spatial and diurnal variation of precipitation systems over Asia
M. Hirose (1), K. Nakamura (2)
(1) Earth Observation Research and application Center, Japan Aerospace Exploration Agency
(2) Hydrospheric Atmospheric Research Center, Nagoya University
The spatial and diurnal variation of rainfall over Asia was
investigated using the Tropical Rainfall Measuring
Mission/Precipitation Radar (TRMM PR) data for four seasons
during 1998-2003. As the sampling errors were reduced for each
month, the fine-spatial distribution of rainfall amount and
scale-based precipitation systems became detectable.
The regional variation of the prevailing
precipitation systems, having close relationship to the maximum
hourly rainfall, was shown by examining the fine-spatial
distribution of rainfall amount and scale-based precipitation
systems.
The number of the precipitation systems was highest in summer
over Asia affected by monsoon. Cumulus-scale systems occurred
most frequently around early afternoon over most of land. On
the south-facing slopes of the Himalayas, the daytime genesis
of the small systems was outstanding. Over the Tibetan Plateau,
the occurrence of the small systems was larger than other regions
such as inland India. On the other hand, meso-scale or synoptic-scale
systems showed significant regional variation in the diurnal cycle.
Their maximum occurrence appeared in the evening over near-flat
landmasses. The wide-spread systems with severe rain pixels
developed over the foothill of the Himalayas at late
night-early morning. The systems were well separated from the
daytime-convection.
Over ocean, in addition to the morning signature, spatially
inhomogeneous and systematic characteristics were shown over
the offshore region, for example, around the Maritime Continent.
The large precipitation systems characterized the total number of
rain pixels and total rainfall amount significantly. Time of the
maximum rainfall for all systems corresponded with one for the
large systems within 3 hours over most (86 %) of the region
which made up of a majority of the large systems.
Submittal Information
Name :
Date :
Masafumi Hirose
06-Aug-04-14:50:39
Organization :
Theme :
Earth Observation Researchand application Center, Japan Aerospace Exploration Agency
Theme 8
Address :
Presentation :
Office Tower 22F, Harumi Island Triton Square, 1-8-10, Harumi, Chuo-ku, Tokyo 104-6023 JAPAN