The Role of Intraseasonal Variability in the Nature of Asian Monsoon Precipitation

Journal of Climate - Tập 20 Số 17 - Trang 4402-4424 - 2007
Carlos D. Hoyos1, P. J. Webster1
1School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia

Tóm tắt

Abstract The structure of the mean precipitation of the south Asian monsoon is spatially complex. Embedded in a broad precipitation maximum extending eastward from 70°E to the northwest tropical Pacific Ocean are strong local maxima to the west of the Western Ghats mountain range of India, in Cambodia extending into the eastern China Sea, and over the eastern tropical Indian Ocean and the Bay of Bengal (BoB), where the strongest large-scale global maximum in precipitation is located. In general, the maximum precipitation occurs over the oceans and not over the land regions. Distinct temporal variability also exists with time scales ranging from days to decades. Neither the spatial nor temporal variability of the monsoon can be explained simply as the response to the cross-equatorial pressure gradient force between the continental regions of Asia and the oceans of the Southern Hemisphere, as suggested in classical descriptions of the monsoon. Monthly (1979–2005) and daily (1997–present) rainfall estimates from the Global Precipitation Climatology Project (GPCP), 3-hourly (1998–present) rainfall estimates from the Tropical Rainfall Measuring Mission (TRMM) microwave imager (TMI) estimates of sea surface temperature (SST), reanalysis products, and satellite-determined outgoing longwave radiation (OLR) data were used as the basis of a detailed diagnostic study to explore the physical basis of the spatial and temporal nature of monsoon precipitation. Propagation characteristics of the monsoon intraseasonal oscillations (MISOs) and biweekly signals from the South China Sea, coupled with local and regional effects of orography and land–atmosphere feedbacks are found to modulate and determine the locations of the mean precipitation patterns. Long-term variability is found to be associated with remote climate forcing from phenomena such as El Niño–Southern Oscillation (ENSO), but with an impact that changes interdecadally, producing incoherent responses of regional rainfall. A proportion of the interannual modulation of monsoon rainfall is found to be the direct result of the cumulative effect of rainfall variability on intraseasonal (25–80 day) time scales over the Indian Ocean. MISOs are shown to be the main modulator of weather events and encompass most synoptic activity. Composite analysis shows that the cyclonic system associated with the northward propagation of a MISO event from the equatorial Indian Ocean tends to drive moist air toward the Burma mountain range and, in so doing, enhances rainfall considerably in the northeast corner of the bay, explaining much of the observed summer maximum oriented parallel to the mountains. Similar interplay occurs to the west of the Ghats. While orography does not seem to play a defining role in MISO evolution in any part of the basin, it directly influences the cumulative MISO-associated rainfall, thus defining the observed mean seasonal pattern. This is an important conclusion since it suggests that in order for the climate models to reproduce the observed seasonal monsoon rainfall structure, MISO activity needs to be well simulated and sharp mountain ranges well represented.

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Tài liệu tham khảo

Adler, 2000, Tropical rainfall distributions determined using TRMM combined with other satellite and rain gauge information., J. Appl. Meteor., 39, 2007, 10.1175/1520-0450(2001)040<2007:TRDDUT>2.0.CO;2

Adler, 2003, The Version-2 Global Precipitation Climatology Project (GPCP) monthly precipitation analysis (1979–present)., J. Hydrometeor., 4, 1147, 10.1175/1525-7541(2003)004<1147:TVGPCP>2.0.CO;2

Agudelo, 2006, Transition between suppressed and active phases of intraseasonal oscillations in the Indo-Pacific warm pool., J. Climate, 19, 5519, 10.1175/JCLI3924.1

Annamalai, 2001, Active/break cycles: Diagnosis of the intraseasonal variability of the Asian summer monsoon., Climate Dyn., 18, 85, 10.1007/s003820100161

Cadet, 1983, The monsoon over the Indian Ocean during summer 1975. Part II: Break and active monsoons., Mon. Wea. Rev., 111, 95, 10.1175/1520-0493(1983)111<0095:TMOTIO>2.0.CO;2

Gadgil, 1998, Monsoon precipitation in the AMIP runs., Climate Dyn., 14, 659, 10.1007/s003820050248

Gadgil, 1999, On growth and fluctuation of Indian foodgrain production., Curr. Sci., 76, 548

Gadgil, 2002, Use of climate information for farm-level decision making., Agric. Syst., 74, 431, 10.1016/S0308-521X(02)00049-5

Gadgil, 2004, Extremes of the Indian summer monsoon rainfall, ENSO and equatorial Indian Ocean oscillation., Geophys. Res. Lett., 31, 10.1029/2004GL019733

Goswami, 2003, Potential predictability and extended range prediction of Indian summer monsoon breaks., Geophys. Res. Lett., 30, 10.1029/2003GL017810

Goswami, 2003, Clustering of synoptic activity by Indian summer monsoon intraseasonal oscillations., Geophys. Res. Lett., 30, 10.1029/2002GL016734

Grossman, 1984, Interaction of low-level flow with the Western Ghat Mountains and offshore convection in the summer monsoon., Mon. Wea. Rev., 112, 652, 10.1175/1520-0493(1984)112<0652:IOLLFW>2.0.CO;2

Grossman, 1990, The distribution of deep convection over ocean and land during the Asian summer monsoon., J. Climate, 3, 1032, 10.1175/1520-0442(1990)003<1032:TDODCO>2.0.CO;2

Hartmann, 1989, Intraseasonal periodicities in Indian rainfall., J. Atmos. Sci., 46, 2838, 10.1175/1520-0469(1989)046<2838:IPIIR>2.0.CO;2

Hendon, 2000, Medium-range forecast errors associated with active episodes of the Madden–Julian oscillation., Mon. Wea. Rev., 128, 69, 10.1175/1520-0493(2000)128<0069:MRFEAW>2.0.CO;2

Huffman, 1997, The Global Precipitation Climatology Project (GPCP) combined precipitation dataset., Bull. Amer. Meteor. Soc., 78, 5, 10.1175/1520-0477(1997)078<0005:TGPCPG>2.0.CO;2

Huffman, 2001, Global precipitation at one-degree daily resolution from multisatellite observations., J. Hydrometeor., 2, 36, 10.1175/1525-7541(2001)002<0036:GPAODD>2.0.CO;2

Jiang, 2004, Structures and mechanisms of the northward propagating boreal summer intraseasonal oscillation., J. Climate, 17, 1022, 10.1175/1520-0442(2004)017<1022:SAMOTN>2.0.CO;2

Kalnay, 1996, The NCEP/NCAR 40-Year Reanalysis Project., Bull. Amer. Meteor. Soc., 77, 437, 10.1175/1520-0477(1996)077<0437:TNYRP>2.0.CO;2

Kirtman, 2000, On the influence of the Indian summer monsoon on ENSO., Quart. J. Roy. Meteor. Soc., 126, 213, 10.1002/qj.49712656211

Knutson, 1987, 30–60 day atmospheric oscillations: Composite life cycles of convection and circulation anomalies., Mon. Wea. Rev., 115, 1407, 10.1175/1520-0493(1987)115<1407:DAOCLC>2.0.CO;2

Krishnamurti, 1980, The 10 to 20 day westward propagating mode and “breaks in the monsoon.”., Tellus, 32, 15, 10.3402/tellusa.v32i1.10476

Krishnamurti, 1982, The 30–50 day mode at 850 mb during MONEX., J. Atmos. Sci., 39, 2088, 10.1175/1520-0469(1982)039<2088:TDMAMD>2.0.CO;2

Kumar, 1999, On the weakening relationship between the Indian monsoon and ENSO., Science, 284, 2156, 10.1126/science.284.5423.2156

Lal, 1999, Growth and yield responses of soybean in Madhya Pradesh, India to climate variability and change., Agric. For. Meteor., 93, 53, 10.1016/S0168-1923(98)00105-1

Lawrence, 2001, Interannual variations of the intraseasonal oscillation in the South Asian summer monsoon region., J. Climate, 14, 2910, 10.1175/1520-0442(2001)014<2910:IVOTIO>2.0.CO;2

Lawrence, 2002, The boreal summer intraseasonal oscillation: Relationship between northward and eastward movement of convection., J. Atmos. Sci., 59, 1593, 10.1175/1520-0469(2002)059<1593:TBSIOR>2.0.CO;2

Liebmann, 1996, Description of a complete (interpolated) outgoing longwave radiation dataset., Bull. Amer. Meteor. Soc., 77, 1275

Murakami, 1976, Cloudiness fluctuations during the summer monsoon., J. Meteor. Soc. Japan, 54, 175, 10.2151/jmsj1965.54.3_175

Palmer, 1994, Chaos and predictability in forecasting the monsoons., Proc. Indian Natl. Sci. Acad., 60A, 57

Parthasarathy, 1987, Droughts/floods in the summer monsoon rainfall season over different meteorological subdivisions of India for the period 1871–1984., J. Climatol., 7, 57, 10.1002/joc.3370070106

Parthasarathy, 1988, Regression model for estimation of Indian food grain production from Indian summer rainfall., Agric. For. Meteor., 42, 167, 10.1016/0168-1923(88)90075-5

Quan, 2004, Seasonality in SST-forced atmospheric short-term climate predictability., J. Climate, 17, 3090, 10.1175/1520-0442(2004)017<3090:SISASC>2.0.CO;2

Saji, 1999, A dipole mode in the tropical Indian Ocean., Nature, 401, 360, 10.1038/43854

Salby, 1994, Intraseasonal behavior of clouds, temperature, and motion in the Tropics., J. Atmos. Sci., 51, 2207, 10.1175/1520-0469(1994)051<2207:IBOCTA>2.0.CO;2

Sengupta, 2001, Oscillations of Bay of Bengal sea surface temperature during the 1998 summer monsoon., Geophys. Res. Lett., 28, 2033, 10.1029/2000GL012548

Sikka, 1980, On the maximum cloud zone and the ITCZ over Indian longitudes during the southwest monsoon., Mon. Wea. Rev., 108, 1840, 10.1175/1520-0493(1980)108<1840:OTMCZA>2.0.CO;2

Slingo, 1999, On the predictability of the interannual behavior of the Madden–Julian oscillation and its relationship with El Niño., Quart. J. Roy. Meteor. Soc., 125, 583

Sperber, 1996, Interannual tropical rainfall variability in general circulation model simulations associated with the Atmospheric Model Intercomparison Project., J. Climate, 9, 2727, 10.1175/1520-0442(1996)009<2727:ITRVIG>2.0.CO;2

Stephens, 2004, Observational evidence for the mutual regulation of the tropical hydrological cycle and tropical sea surface temperatures., J. Climate, 17, 2213, 10.1175/1520-0442(2004)017<2213:OEFTMR>2.0.CO;2

Torrence, 1998, A practical guide to wavelet analysis., Bull. Amer. Meteor. Soc., 79, 61, 10.1175/1520-0477(1998)079<0061:APGTWA>2.0.CO;2

Torrence, 1999, Interdecadal changes in the ENSO–monsoon system., J. Climate, 12, 2679, 10.1175/1520-0442(1999)012<2679:ICITEM>2.0.CO;2

Waliser, 2003, Dynamical predictability of intraseasonal variability associated with the Asian summer monsoon., Quart. J. Roy. Meteor. Soc., 129, 2897, 10.1256/qj.02.51

Waliser, 2003, AGCM simulations of intraseasonal variability associated with the Asian summer monsoon., Climate Dyn., 21, 423, 10.1007/s00382-003-0337-1

Wang, 2002, Rainy seasons of the Asian–Pacific summer monsoon., J. Climate, 15, 386, 10.1175/1520-0442(2002)015<0386:RSOTAP>2.0.CO;2

Wang, 2005, Antecedents and self-induction of active-break south Asian monsoon unraveled by satellites., Geophys. Res. Lett., 32

Webster, 1983, Mechanisms of monsoon low-frequency variability: Surface hydrological effects., J. Atmos. Sci., 40, 2110, 10.1175/1520-0469(1983)040<2110:MOMLFV>2.0.CO;2

Webster, 1992, Monsoon and ENSO: Selectively interactive systems., Quart. J. Roy. Meteor. Soc., 118, 877, 10.1002/qj.49711850705

Webster, 2004, Prediction of monsoon rainfall and river discharge on 15–30-day time scales., Bull. Amer. Meteor. Soc., 85, 1745, 10.1175/BAMS-85-11-1745

Webster, 1998, Monsoons: Processes, predictability and the prospects for prediction., J. Geophys. Res., 103, 14451, 10.1029/97JC02719

Webster, 1999, Coupled ocean–atmosphere dynamics in the Indian Ocean during 1997–98., Nature, 401, 356, 10.1038/43848

Wentz, 1997, A well-calibrated ocean algorithm for Special Sensor Microwave/Imager., J. Geophys. Res., 102, 8703, 10.1029/96JC01751

Wentz, 2000, Precise climate monitoring using complementary satellite data sets., Nature, 403, 414, 10.1038/35000184

Xie, 2006, Role of narrow mountains in large-scale organization of Asian monsoon convection., J. Climate, 19, 3420, 10.1175/JCLI3777.1

Yasunari, 1979, Cloudiness fluctuations associated with the Northern Hemisphere summer monsoon., J. Meteor. Soc. Japan, 57, 227, 10.2151/jmsj1965.57.3_227

Yasunari, 1981, Structure of an Indian summer monsoon system with around 40-day period., J. Meteor. Soc. Japan, 59, 336, 10.2151/jmsj1965.59.3_336

Zuidema, 2003, Convective clouds over the Bay of Bengal., Mon. Wea. Rev., 131, 780, 10.1175/1520-0493(2003)131<0780:CCOTBO>2.0.CO;2