The characteristics of the summer precipitation diurnal cycle over South Asia and East Asia during 2001–13 are investigated based on the high spatiotemporal resolution estimates of the CPC(Climate Prediction Center) ...The characteristics of the summer precipitation diurnal cycle over South Asia and East Asia during 2001–13 are investigated based on the high spatiotemporal resolution estimates of the CPC(Climate Prediction Center) Morphing(CMORPH) technique. The results show that summer precipitation over South Asia and East Asia possesses a remarkable diurnal cycle, with obvious regional differences. Over the coastal areas, plateau, and high mountains, summer precipitation peaks in the late afternoon; while over low altitude areas, such as valleys, basins, and inshore seas, it peaks during midnight to early morning. In addition to these general features consistent with previous studies, the high resolution CMORPH technique can depict finer regional details, such as the less coherent phase pattern over a few regions. Besides, through comparative analysis of the diurnal cycle strength and precipitation fields, the authors find that for humid areas the summer precipitation diurnal cycle is especially significant over Southeast China, the Sichuan Basin, Hainan Province, Taiwan Province, the Philippines, and Indonesia. And it is relatively weak over the south of Northeast China, central East China, Yunnan Province, the central Indian Peninsula, and most oceanic areas. Comparisons between two satellite datasets—those of the CMORPH and Tropical Rainfall Measuring Mission(TRMM) 3B42 products—are also presented. For summer precipitation and the main diurnal cycle features, the results from both products agree over most regions, except a few areas, e.g., the Tibetan Plateau.展开更多
Climatological characteristics of diurnal variations in summer precipitation over the Asian monsoon region are comprehensively investigated based on the Tropical Rainfall Measuring Mission(TRMM) satellite data during ...Climatological characteristics of diurnal variations in summer precipitation over the Asian monsoon region are comprehensively investigated based on the Tropical Rainfall Measuring Mission(TRMM) satellite data during 1998-2008.The topographic influence on the diurnal variations and phase propagations of maximum precipitation are identified according to spatiotemporal distributions of the amplitude and peak time of the diurnal precipitation.The amplitude and phase of diurnal precipitation show a distinct geographical pattern.Significant diurnal variations occur over most of continental and coastal areas including the Maritime Continent,with the relative amplitude exceeding 40%,indicating that the precipitation peak is 1.4 times the 24-h mean.Over the landside coasts such as southeastern China and Indochina Peninsula,the relative amplitude is even greater than 100%.Although the diurnal variations of summer precipitation over the continental areas are characterized by an afternoon peak(1500-1800 Local Solar Time(LST)),over the central Indochina Peninsula and central and southern Indian Peninsula the diurnal phase is delayed to after 2100 LST,suggesting the diurnal behaviors over these areas different from the general continental areas.The weak diurnal variations with relative amplitudes less than 40% exist mainly over oceanic areas in the western Pacific and most of Indian Ocean,with the rainfall peak mainly occurring from midnight to early morning(0000-0600 LST),indicating a typical oceanic regime characterized by an early morning peak.However,apparent exceptions occur over the South China Sea(SCS),Bay of Bengal(BOB),and eastern Arabian Sea,with the rainfall peak occurring in daytime(0900-1500 LST).Prominent meridional propagations of the diurnal phase exist in South Asia and East Asia.Along the eastern Indian Peninsula,there is not only the southward phase propagation with the peak occurring around 25°N but also the northward phase propagation with the peak beginning with the southernmost continent,and both reach the central Indian continent to finish.Along the same longitudes where southern China and Kalimantan are located,the diurnal phase of the former propagates from the oceanic area(northern SCS) toward the inland continent,while the phase of the latter propagates from the land area toward the outside sea,showing a landward or seaward coastal diurnal regime.A distinct zonal propagation of the diurnal phase is observed over the BOB oceanic area.The maximum precipitation zone originates from the land-sea boundary of the eastern coast of the Indian peninsula at around 0300 LST,and then propagates eastward with increasing time to reach the eastern coast of the BOB on 1800 LST,finally migrates into the Indochina continent on about 2100 LST.展开更多
基金supported by the National Basic Research Program of China(Grant No.2013CB430201)the China Meteorological Administration Special Fund for Scientific Research in the Public Interest(Grant No.GYHY201206008)
文摘The characteristics of the summer precipitation diurnal cycle over South Asia and East Asia during 2001–13 are investigated based on the high spatiotemporal resolution estimates of the CPC(Climate Prediction Center) Morphing(CMORPH) technique. The results show that summer precipitation over South Asia and East Asia possesses a remarkable diurnal cycle, with obvious regional differences. Over the coastal areas, plateau, and high mountains, summer precipitation peaks in the late afternoon; while over low altitude areas, such as valleys, basins, and inshore seas, it peaks during midnight to early morning. In addition to these general features consistent with previous studies, the high resolution CMORPH technique can depict finer regional details, such as the less coherent phase pattern over a few regions. Besides, through comparative analysis of the diurnal cycle strength and precipitation fields, the authors find that for humid areas the summer precipitation diurnal cycle is especially significant over Southeast China, the Sichuan Basin, Hainan Province, Taiwan Province, the Philippines, and Indonesia. And it is relatively weak over the south of Northeast China, central East China, Yunnan Province, the central Indian Peninsula, and most oceanic areas. Comparisons between two satellite datasets—those of the CMORPH and Tropical Rainfall Measuring Mission(TRMM) 3B42 products—are also presented. For summer precipitation and the main diurnal cycle features, the results from both products agree over most regions, except a few areas, e.g., the Tibetan Plateau.
基金supported by Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No.KZCX2-YW- Q11-04)National Basic Research Program of China (Grant Nos.2011CB403505 and 2010CB950402)National Natural Science Foundation of China (Grant Nos.40975052)
文摘Climatological characteristics of diurnal variations in summer precipitation over the Asian monsoon region are comprehensively investigated based on the Tropical Rainfall Measuring Mission(TRMM) satellite data during 1998-2008.The topographic influence on the diurnal variations and phase propagations of maximum precipitation are identified according to spatiotemporal distributions of the amplitude and peak time of the diurnal precipitation.The amplitude and phase of diurnal precipitation show a distinct geographical pattern.Significant diurnal variations occur over most of continental and coastal areas including the Maritime Continent,with the relative amplitude exceeding 40%,indicating that the precipitation peak is 1.4 times the 24-h mean.Over the landside coasts such as southeastern China and Indochina Peninsula,the relative amplitude is even greater than 100%.Although the diurnal variations of summer precipitation over the continental areas are characterized by an afternoon peak(1500-1800 Local Solar Time(LST)),over the central Indochina Peninsula and central and southern Indian Peninsula the diurnal phase is delayed to after 2100 LST,suggesting the diurnal behaviors over these areas different from the general continental areas.The weak diurnal variations with relative amplitudes less than 40% exist mainly over oceanic areas in the western Pacific and most of Indian Ocean,with the rainfall peak mainly occurring from midnight to early morning(0000-0600 LST),indicating a typical oceanic regime characterized by an early morning peak.However,apparent exceptions occur over the South China Sea(SCS),Bay of Bengal(BOB),and eastern Arabian Sea,with the rainfall peak occurring in daytime(0900-1500 LST).Prominent meridional propagations of the diurnal phase exist in South Asia and East Asia.Along the eastern Indian Peninsula,there is not only the southward phase propagation with the peak occurring around 25°N but also the northward phase propagation with the peak beginning with the southernmost continent,and both reach the central Indian continent to finish.Along the same longitudes where southern China and Kalimantan are located,the diurnal phase of the former propagates from the oceanic area(northern SCS) toward the inland continent,while the phase of the latter propagates from the land area toward the outside sea,showing a landward or seaward coastal diurnal regime.A distinct zonal propagation of the diurnal phase is observed over the BOB oceanic area.The maximum precipitation zone originates from the land-sea boundary of the eastern coast of the Indian peninsula at around 0300 LST,and then propagates eastward with increasing time to reach the eastern coast of the BOB on 1800 LST,finally migrates into the Indochina continent on about 2100 LST.
