The land-sea thermal contrast is an important driver for monsoon interannual variability and the monsoon onset.The thermal contrast between the Tibetan Plateau and the tropical Indian Ocean at the mid-upper tropospher...The land-sea thermal contrast is an important driver for monsoon interannual variability and the monsoon onset.The thermal contrast between the Tibetan Plateau and the tropical Indian Ocean at the mid-upper troposphere is proposed as a thermal contrast index(TCI)for South Asian monsoon.The authors investigate the TCI associated with South Asian summer monsoon(SASM)intensity and SASM onset.It is observed that the TCI considering the Tibetan Plateau and tropical Indian Ocean demonstrates a stronger and closer correlation with SASM intensity(0.87)than either the Tibetan Plateau(0.42)or tropical Indian Ocean(-0.60)singly.It is implied that the TCI could preferably represent the impact of land-sea thermal condition on SASM activity.Further analysis reveals that the evolution of TCI is related to the SASM onset.The TCI is almost always larger in early onset years than it is in late onset years during the period before SASM onset.In addition,the change of the pentad-by-pentad increment of TCI leads the SASM variation.The correlation coefficient between the TCI increment and SASM index reaches a maximum when the TCI increment leads by 15 pentads.The results of this study show that the TCI plays an important role in SASM activities and is a potential indicator for SASM onset forecasting.展开更多
The authors present the effects of the total organic carbon( TOCinert) during pyrolysis and how it overall affects the estimates of the hydrocarbon index( HI) using the cross plot S2 vs. TOC graph. A total of 21 drill...The authors present the effects of the total organic carbon( TOCinert) during pyrolysis and how it overall affects the estimates of the hydrocarbon index( HI) using the cross plot S2 vs. TOC graph. A total of 21 drillcore samples consisting of the non-carbonaceous mudstones,carbonaceous mudstones,coaly mudstones and coals with S2> 0. 35 are selected and used. The average TOC for the sampled population is 10. 36 wt%.TOCinertmeasured from the S2 vs. TOC graph is 2. 97 wt% and the average pyrolysable TOCliveis 7. 39 wt%. The HI is 102 mg HC / g TOC and the pyrolysable HI is 175 mg HC / g TOC,indicating that the TOCinertor mi-neral matrix adsorbs some of the hydrocarbons liberated during pyrolysis resulting into the low HI values which affects the correct determination of the source rock potential. Other applications of the S2 vs. TOC cross plot have been used to determine the depositional system tracts. The high stand system tract is also determined through this method.展开更多
Several dams have been constructed in Ethiopia, East Africa to support electricity and/or irrigation. Fishes were introduced to some of these dams. Thus, the objective of this study was to assess the dynamics and cond...Several dams have been constructed in Ethiopia, East Africa to support electricity and/or irrigation. Fishes were introduced to some of these dams. Thus, the objective of this study was to assess the dynamics and condition factor of Oriochromis niloticus in Korir and Lailay Wukro Dams, Northern Ethiopias. The study was conducted by deploying two gill net, every month in the littoral and pelagic zones of the two dams from August 2011 to May 2012. A total of 524 O. niloticus, 278 from Lailay Wukro and 246 from Korir dams were collected. The monthly catch per unit effort （CPUE） showed significant variation among months, the highest catch was in May and the least was in January 2012 （P 〈 0.000）. Catches of fish encountered higher in the littoral （69.1%） than in the pelagic zones （30.9%） （P 〈 0.000）. The condition factor of O. niloticus in the two reservoirs remains high, in Korir 2.05 and in Lailay Wukro 1.65 （P 〈 0.000）. In these small tropical dams, O. niloticus mature as they are smaller in size （Ls0： TL average 22.5 cm）. The ratio of male to female was 1.3：1 （P 〈 0.016）. The two dams have favorable condition for high production of O. niloticus. This high potential for fish production in the dams may be sustainable if the local authorities set a regulation to control the illegal fishing activity.展开更多
基金supported jointly by the Strategic Priority Research Program of the Chinese Academy of Sciences[Grant number XDA20060501]the National Natural Science Foundation of China[Grant numbers U1902209 and 91637208]。
文摘The land-sea thermal contrast is an important driver for monsoon interannual variability and the monsoon onset.The thermal contrast between the Tibetan Plateau and the tropical Indian Ocean at the mid-upper troposphere is proposed as a thermal contrast index(TCI)for South Asian monsoon.The authors investigate the TCI associated with South Asian summer monsoon(SASM)intensity and SASM onset.It is observed that the TCI considering the Tibetan Plateau and tropical Indian Ocean demonstrates a stronger and closer correlation with SASM intensity(0.87)than either the Tibetan Plateau(0.42)or tropical Indian Ocean(-0.60)singly.It is implied that the TCI could preferably represent the impact of land-sea thermal condition on SASM activity.Further analysis reveals that the evolution of TCI is related to the SASM onset.The TCI is almost always larger in early onset years than it is in late onset years during the period before SASM onset.In addition,the change of the pentad-by-pentad increment of TCI leads the SASM variation.The correlation coefficient between the TCI increment and SASM index reaches a maximum when the TCI increment leads by 15 pentads.The results of this study show that the TCI plays an important role in SASM activities and is a potential indicator for SASM onset forecasting.
文摘The authors present the effects of the total organic carbon( TOCinert) during pyrolysis and how it overall affects the estimates of the hydrocarbon index( HI) using the cross plot S2 vs. TOC graph. A total of 21 drillcore samples consisting of the non-carbonaceous mudstones,carbonaceous mudstones,coaly mudstones and coals with S2> 0. 35 are selected and used. The average TOC for the sampled population is 10. 36 wt%.TOCinertmeasured from the S2 vs. TOC graph is 2. 97 wt% and the average pyrolysable TOCliveis 7. 39 wt%. The HI is 102 mg HC / g TOC and the pyrolysable HI is 175 mg HC / g TOC,indicating that the TOCinertor mi-neral matrix adsorbs some of the hydrocarbons liberated during pyrolysis resulting into the low HI values which affects the correct determination of the source rock potential. Other applications of the S2 vs. TOC cross plot have been used to determine the depositional system tracts. The high stand system tract is also determined through this method.
文摘Several dams have been constructed in Ethiopia, East Africa to support electricity and/or irrigation. Fishes were introduced to some of these dams. Thus, the objective of this study was to assess the dynamics and condition factor of Oriochromis niloticus in Korir and Lailay Wukro Dams, Northern Ethiopias. The study was conducted by deploying two gill net, every month in the littoral and pelagic zones of the two dams from August 2011 to May 2012. A total of 524 O. niloticus, 278 from Lailay Wukro and 246 from Korir dams were collected. The monthly catch per unit effort （CPUE） showed significant variation among months, the highest catch was in May and the least was in January 2012 （P 〈 0.000）. Catches of fish encountered higher in the littoral （69.1%） than in the pelagic zones （30.9%） （P 〈 0.000）. The condition factor of O. niloticus in the two reservoirs remains high, in Korir 2.05 and in Lailay Wukro 1.65 （P 〈 0.000）. In these small tropical dams, O. niloticus mature as they are smaller in size （Ls0： TL average 22.5 cm）. The ratio of male to female was 1.3：1 （P 〈 0.016）. The two dams have favorable condition for high production of O. niloticus. This high potential for fish production in the dams may be sustainable if the local authorities set a regulation to control the illegal fishing activity.
