Diurnal variation of tropical cyclone （TC rainfall in the western North Pacific （WNP） is investi gated using the high-resolution Climate Prediction Ce~ ter＇s morphing technique （CMORPH） products obtaine from the...Diurnal variation of tropical cyclone （TC rainfall in the western North Pacific （WNP） is investi gated using the high-resolution Climate Prediction Ce~ ter＇s morphing technique （CMORPH） products obtaine from the National Oceanic and Atmospheric Administra tion （NOAA）. From January 2008 to October 2010, 7 TCs and 389 TC rainfall days were reported by the Joir Typhoon Warning Center＇s （JTWC） best-track record. Th TC rain rate was partitioned using the Objective Synopti Analysis Technique （OSAT） and interpolated into Local Standard Time （LST）. Harmonic analysis was applied t analyze the diurnal variation of the precipitation. Obviou diurnal cycles were seen in approximately 70% of the TC rainfall days. The harmonic amplitude and phase of the mean TC rainfall rate vary with TC intensity, life stage, season, and spatial distribution. On the basis of intensity, tropical de- pressions （TDs） exhibit the highest precipitation variation amplitude （PVA）, at approximately 30%, while super ty- phoons （STs） contain the lowest PVA, at less than 22%. On the basis of lifetime stage, the PVA in the decaying stage （more than 37%） is stronger than that in the devel oping （less than 20%） and sustaining （28%） stages. On the basis of location, the PVA of more than 35% （less than 18%） is the highest （lowest） over the high-latitude oceanic areas （the eastern ocean of the Philippine Islands）. In ad dition, a sub-diurnal cycle of TC rainfall occurs over the high-latitude oceans. On the basis of season, the diurnal variation is more pronounced during summer and winter, at approximately 30% and 32%, respectively, and is weaker in spring and autumn, at approximately 22% and 24%, respectively.展开更多
基金supported by the National Basic Research Program of China (Grant No.2009CB421504)The National Natural Science Foundation of China (Grant Nos. 41275048 and 40921160380)
文摘Diurnal variation of tropical cyclone （TC rainfall in the western North Pacific （WNP） is investi gated using the high-resolution Climate Prediction Ce~ ter＇s morphing technique （CMORPH） products obtaine from the National Oceanic and Atmospheric Administra tion （NOAA）. From January 2008 to October 2010, 7 TCs and 389 TC rainfall days were reported by the Joir Typhoon Warning Center＇s （JTWC） best-track record. Th TC rain rate was partitioned using the Objective Synopti Analysis Technique （OSAT） and interpolated into Local Standard Time （LST）. Harmonic analysis was applied t analyze the diurnal variation of the precipitation. Obviou diurnal cycles were seen in approximately 70% of the TC rainfall days. The harmonic amplitude and phase of the mean TC rainfall rate vary with TC intensity, life stage, season, and spatial distribution. On the basis of intensity, tropical de- pressions （TDs） exhibit the highest precipitation variation amplitude （PVA）, at approximately 30%, while super ty- phoons （STs） contain the lowest PVA, at less than 22%. On the basis of lifetime stage, the PVA in the decaying stage （more than 37%） is stronger than that in the devel oping （less than 20%） and sustaining （28%） stages. On the basis of location, the PVA of more than 35% （less than 18%） is the highest （lowest） over the high-latitude oceanic areas （the eastern ocean of the Philippine Islands）. In ad dition, a sub-diurnal cycle of TC rainfall occurs over the high-latitude oceans. On the basis of season, the diurnal variation is more pronounced during summer and winter, at approximately 30% and 32%, respectively, and is weaker in spring and autumn, at approximately 22% and 24%, respectively.
