Monsoon Research Prospects with GPM

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Monsoon Research Prospects with GPM

• Yasu-Masa Kodama
• Department of Earth and Environmental Sciences,
• Hirosaki University, JAPAN

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Major part of precipitation in the tropics and
subtropics concentrates to summer monsoon
rainfall areas.
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Alternation of predominant rainfall types
observed at the monsoon onset. By Kodama,
Ohta, Katsumata, Mori, Sato, et al.

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Rainfall increases and Lightning is suppressed
after the monsoon onset
Flash Counts(/10day)(LIS)
Wind at 925hPa level
Near surface Rainfall (mm/day) (PR)
Upper panels Pre Monsoon period (mid-April to
early May in 1998-2000)
Lower panels Monsoon Period (July in 1998-2000)
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Rainfall increases and Lightning is suppressed
after the monsoon onset
Flash Counts(/10day)
Near surface rainfall (mm/day)
Wind at 925hPa level
Upper panels Pre Monsoon period (October in
1998-2000)
Lower panels Monsoon period (December in
1998-2000)
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Classification of rainfall(PRH algorism by S.
Satoh, 2004)

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Bangladesh (1998-2000)

Study Area
Monsoon Onset
Premonsoon period Convective Rain with Active
Lightning is dominated. Monsoon period
Stratiform Rain increased and lightning is
suppressed.
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North-Eastern part of Thailand
Study Area
Premonsoon period Convective Rain with Active
Lightning is dominated. Monsoon period
Stratiform Rain increases and lightning is
fairly suppressed.
Monsoon Onset
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Amazon Basin (1998-2000)
Study Area
Premonsoon period Convective Rain with Active
Lightning is dominated. Monsoon period
Stratiform Rain increases and lightning is
suppressed.
Monsoon Onset defined by cross-equatorial flow
(Fu et al, 2003)
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Pre-monsoon precipitation is highly convective.
Pre-monsoon precipitation may contribute to the
monsoon onset as an atmospheric heat source

Ueda et al. (2003a), J. Climate ,16, 2309-2324 Fu
et al. (2003), IUGG 2003.
Our result is consistent to the suggestion of
these studies. Next step Evaluation of latent
heating before and after the monsoon onset
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TRMM Era? GPM Era

• Extension of observation area
• Observation of ice phase precipitation
• 3-hourly precipitation moniting by microwave
  instruments of the core- and co-satellites of
  GPM.

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GPM core-satellite observes the whole summer
monsoon systems
Tibetan Plateau
BFZ
SACZ
Zhou and Lau, 1998 J.Climate
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Western Plateau
pre-monsoon period
positive Q1
W
E
positive Q2 (moisture sink)
condensation heating in addition to the sensible
heat supply
Ueda et al. (2003a), J. Climate ,16, 2309-2324
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Diurnal variation over Tibetan Plateau
100-day averaged profiles of Q1 and Q2 over area
C. Unit of Q1 and Q2 is K/day
Upper air observation stations during
FGGE-SMONEX period
Nitta et al., 1983
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Winter Monsoon
Summer Monsoon
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Precipitation maintained by winter monsoon
Sapporo
Aomori
40N
Niigata
Kanazawa
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Linkage between Eurasian Snow Cover and Indian
Monsoon rainfall
Snow cover (Asian Cont.)
Precipitation (India))
Bamzai and Shukla 1999, J. Climate
Harn and Shukla 1976
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GPM will provide useful information for monsoon
studies
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Precipitation of Asian Summer Monsoon extend
outside of the TRMM coverage.