Search Results
continental heavy rainfall latitude zones, but in contrast to the oceanic regime, seemingly nearly equal contributions in the subtropics, except for the Southern Hemisphere in boreal winter and the Northern Hemisphere in summer. To emphasize the contrasts, relative contributions (given in percent) to the total seasonal rainfall from the convective and stratiform categories are shown in Fig. 5 . (As in Fig. 4 , the results are nearly identical with respect to the two algorithms.) Now, the actual
continental heavy rainfall latitude zones, but in contrast to the oceanic regime, seemingly nearly equal contributions in the subtropics, except for the Southern Hemisphere in boreal winter and the Northern Hemisphere in summer. To emphasize the contrasts, relative contributions (given in percent) to the total seasonal rainfall from the convective and stratiform categories are shown in Fig. 5 . (As in Fig. 4 , the results are nearly identical with respect to the two algorithms.) Now, the actual
frequent convective clouds associated with the ITCZ. Over the eastern Pacific and Atlantic Oceans large deficits of afternoon (1400 LT) cloud cover appear in areas dominated by marine stratus clouds. In boreal winter diurnal cycles in cloud cover are small over northern land areas ( Fig. 3 ). Some evidence of diurnal cycles appears in the southern Rocky Mountains in North America, the northern Sahara Desert, and eastern Asia as an excess of clouds at 1400 LT. But the opposite diurnal cycle of cloud
frequent convective clouds associated with the ITCZ. Over the eastern Pacific and Atlantic Oceans large deficits of afternoon (1400 LT) cloud cover appear in areas dominated by marine stratus clouds. In boreal winter diurnal cycles in cloud cover are small over northern land areas ( Fig. 3 ). Some evidence of diurnal cycles appears in the southern Rocky Mountains in North America, the northern Sahara Desert, and eastern Asia as an excess of clouds at 1400 LT. But the opposite diurnal cycle of cloud
the Maritime Continent. Peak local time shifts occur over the inland region of the northeast coast of South America, over the southern slopes of the Himalayas, and over oceanic regions, including the Bay of Bengal, the Gulf of Mexico, and the Maritime Continent. These diurnal variations and their shifts are reported in many studies (e.g., Dai 2001 ; Carbone et al. 2002 ). In some regions, the peak local time derived from PR, TMI, and VIRS is less prominent, perhaps resulting from small sampling
the Maritime Continent. Peak local time shifts occur over the inland region of the northeast coast of South America, over the southern slopes of the Himalayas, and over oceanic regions, including the Bay of Bengal, the Gulf of Mexico, and the Maritime Continent. These diurnal variations and their shifts are reported in many studies (e.g., Dai 2001 ; Carbone et al. 2002 ). In some regions, the peak local time derived from PR, TMI, and VIRS is less prominent, perhaps resulting from small sampling
model’s atmosphere is forced by weekly mean sea surface temperatures (SSTs) that are linearly interpolated into mean daily values, resulting in diurnally constant SSTs. This assumption stems from the fact that the open-ocean surface’s large heat capacity drastically diminishes the daily range of surface temperature compared to land. Diurnally constant SSTs therefore have only a small impact on the diurnal magnitude of turbulent energy fluxes, but the phases are strongly affected ( RR07a ). b. Water
model’s atmosphere is forced by weekly mean sea surface temperatures (SSTs) that are linearly interpolated into mean daily values, resulting in diurnally constant SSTs. This assumption stems from the fact that the open-ocean surface’s large heat capacity drastically diminishes the daily range of surface temperature compared to land. Diurnally constant SSTs therefore have only a small impact on the diurnal magnitude of turbulent energy fluxes, but the phases are strongly affected ( RR07a ). b. Water
applications. We report new results at the continental scale and we delve into some regional aspects of diurnal variability that were not previously examined. Finally, we search for evidence of diurnal anomalies that might occur during phases of El Niño–Southern Oscillation (ENSO; Madden and Julian 1972 ). Pioneering work by Tripoli and Cotton (1989a , b ) established a causal relationship between propagating mesoscale convective systems over the Great Plains and diurnal forcing over the Rockies, which
applications. We report new results at the continental scale and we delve into some regional aspects of diurnal variability that were not previously examined. Finally, we search for evidence of diurnal anomalies that might occur during phases of El Niño–Southern Oscillation (ENSO; Madden and Julian 1972 ). Pioneering work by Tripoli and Cotton (1989a , b ) established a causal relationship between propagating mesoscale convective systems over the Great Plains and diurnal forcing over the Rockies, which
Trenberth 2004 ; Liang et al. 2004 ; Dai 2006 ; Demott et al. 2007 ; Lee et al. 2007 ). The diurnal cycle of precipitation, which comes largely from its frequency variations ( Dai et al. 1999 , 2007 ), has large spatial and seasonal variations. The dominant feature of the oceanic diurnal cycle is a rainfall maximum in early morning (0400–0600 LST), whereas warm-season precipitation peaks in late afternoon (1500–1900 LST) over most (but not all) land areas ( Dai 2001b ; Dai et al. 2007 ). This land
Trenberth 2004 ; Liang et al. 2004 ; Dai 2006 ; Demott et al. 2007 ; Lee et al. 2007 ). The diurnal cycle of precipitation, which comes largely from its frequency variations ( Dai et al. 1999 , 2007 ), has large spatial and seasonal variations. The dominant feature of the oceanic diurnal cycle is a rainfall maximum in early morning (0400–0600 LST), whereas warm-season precipitation peaks in late afternoon (1500–1900 LST) over most (but not all) land areas ( Dai 2001b ; Dai et al. 2007 ). This land
