Generally, short-duration rainfall peaks in the late afternoon, which is closely related to the thermally driven convection induced by surface solar heating (Dai et al. ( 2007b) further demonstrated that precipitation diurnal features over the central eastern China during the warm season are quite different between the short-duration and long-duration rainfall. ( 2007a) revealed that diurnal variations of summer precipitation exhibit considerable regional features among five regions in the contiguous China. In recent years, with the rapid development of the hourly gauge observed and satellite retrieved precipitation dataset, diurnal variability of precipitation has been extensively examined over East Asia. Revealing the spatiotemporal features of precipitation diurnal cycles are not only helpful to understand the physical processes in the rainfall formation but also necessary to evaluate and improve precipitation parameterization schemes in climate models (Betts and Jakob 2002 Dai and Trenberth 2004 Demott et al. 2000 Yang and Smith 2005 He and Zhang 2010). Due to the inhomogeneous underlying surface, monsoon systems, western Pacific subtropical high, and the nocturnal low-level jet, precipitation diurnal cycles present distinct regional and seasonal characteristics (Higgins et al. The late-afternoon peak of the short-duration PA over the southeastern hilly and coastal regions is ascribed to the strong local thermal convections due to the solar heating in afternoon, while the early-evening peak of the short-duration PA over the elevated mountain ranges is significantly contributed by the upward warm-moist wind from the surrounding low-lying basins or plains.ĭiurnal variation of precipitation, as a response to the evolution of synoptic and climatic systems and local forcing, is an important aspect of the local climate and takes a significant feedback on certain thermal and dynamical conditions (Sorooshain et al. Further mechanism analysis suggests that the midnight to morning diurnal evolution of the long-duration rainfall is closely associated with the diurnal variations of the upward branches of thermally driven mountain-plain solenoids and the water vapor transport associated with the accelerated nocturnal southwesterly winds. However, the 4–6 h rainfall leads to the eastward phase time delay of the total rainfall along the Taihang Mountains to its downstream. Along the Tibetan Plateau to its downstream, the diurnal peaks of PA, PF and PI for the total rainfall all exhibit obvious eastward phase time delay mainly due to the diurnal evolutions of long-duration (> 6 h) rainfall. Over the elevated mountain ranges, southeastern hilly and coastal regions, the PA and PF diurnal patterns of the total rainfall generally show predominant late-afternoon peaks, which are closely associated with the short-duration ( \(\leqslant \,\) 3 h) rainfall. Meanwhile, the diurnal peaks of PA and PF (PI) strengthen (weaken) with the sub-grid topography SD enhanced. The PA, PF and PI of the total rainfall show much more pronounced double diurnal peaks with the sub-grid topography standard deviation (SD) decreased. ![]() The precipitation diurnal cycles are significantly affected by the sub-grid terrain fluctuations. Results indicate that the eight typical precipitation diurnal patterns identified by the cluster analysis display pronounced regional features among the plateaus, basins, plains, hilly and coastal areas. Saper CB, Lu J, Chou TC, Gooley J (2005) The hypothalamic integrator for circadian rhythms.Based on the hourly gauge-satellite merged precipitation product with the horizontal resolution of 0.1° latitude/longitude during 2008–2014, diurnal variations of the summer precipitation amount (PA), frequency (PF), and intensity (PI) with different duration time over the regions east to Tibetan Plateau have been systematically revealed in this study. ![]() PhD thesis, Michigan State University, East Lansing, MIįuller PM, Gooley JJ, Saper CB (2006) Neurobiology of the sleep-wake cycle: sleep architecture, circadian regulation, and regulatory feedback. Mahoney M (2003) Sex, surges and circadian rhythms: The timing of reproductive events in a diurnal rodent. PhD thesis, Michigan State University, East Lansing, MI Schwartz MD (2006) Neural substrates of diurnality in the Nile grass rat, Arvicanthis niloticus. Smale L, Lee TM, Nunez AA (2003) Mammalian diurnality: Some facts and gaps. ![]() Klein D, Moore RY, Reppert SM (1991) Suprachiasmatic Nucleus: the mind's clock. Stephan FK (2002) The “other” circadian system: food as a zeitgeber, J Biol Rhythms 17:284–292 In: Knobil E, Neill JD (eds) The physiology of reproduction, Raven Press, New York, pp 487–540 Turrek FW, van Cauter E (1994) Rhythms in reproduction. Moore-Ede M, Sulzman F, Fuller C (1983) The clocks that time us.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |