Based on TOPEX/Poseidon (T/P) and ERS-1 and 2 satellite altimeter data between October 1992 and December 2000, high frequency oscillations with periods less than 150 d are analyzed and their spatial distributions are ...Based on TOPEX/Poseidon (T/P) and ERS-1 and 2 satellite altimeter data between October 1992 and December 2000, high frequency oscillations with periods less than 150 d are analyzed and their spatial distributions are described. The ratio, instead of the energy itself, of the energy corresponding to certain frequency band from power spectrum relative to the total energy in the 20～143 d range is analyzed. The results show that the period of the most energetic oscillations in this band increases with latitude from about 1 month near the tropics to about 4 months near 30°, in agreement with the latitudinal dependency of the phase speed of westward propagating long Rossby waves,which dominate the variability in those latitudes.As a result,the global spatial distributions of the period of the dominant oscillations are largely zonal, with relatively small differences between different ocean basins. It suggests that the oscillations with periods around 60 d are mainly associated with planetary Rossby waves except the often regarded as tidal aliasing.展开更多
In the purple hilly region, erosions and landslides are all serious, and it is of great scientific value and practical significance to study their formation mechanism and distribution features there. In this paper, so...In the purple hilly region, erosions and landslides are all serious, and it is of great scientific value and practical significance to study their formation mechanism and distribution features there. In this paper, soil micromorphological methods and techniques were used to study the erosion zonal distribution in the region. The results indicated: (1) According to erosion process, the spacial distribution zones of the erosions and landslides in the purple hilly region with different solums were divided into scouring erosion zone, transport-diffusion zone, rocks and soil turbulence zone and sediment-bury zone; (2) The soil micromorphologic taxonomic feature identifying different erosion-landslide zone were found by studying the soil micromorphology of erosive zone in purple hilly region; (3) As for the erosion–landslide formation in the region, besides the external factors, the internal factors were found more important and favorable for landslide formation through the studies on the micormorphological features of slide soil.展开更多
The simulated sea surface temperature anomaly(SSTA)over the tropical Pacific during El Ni?o–Southern Oscillation(ENSO)is investigated in three representative coupled models:CESM1-CAM5,FGOALS-s2,and FGOALS-g2.It is fo...The simulated sea surface temperature anomaly(SSTA)over the tropical Pacific during El Ni?o–Southern Oscillation(ENSO)is investigated in three representative coupled models:CESM1-CAM5,FGOALS-s2,and FGOALS-g2.It is found that there is a significant westward shift bias in reproducing the zonal distribution(ZD)of the ENSO-related SSTA in CESM1-CAM5 and FGOALS-s2,whereas the SSTA-ZD simulated by FGOALS-g2 is relatively realistic.Through examining the SSTA-ZD during both warm and cold phases of ENSO separately,the authors reveal that the SSTA-ZD simulation bias during the ENSO cycle mainly lies in the bias during the warm phase.It is noted that both the simulated zonal wind stress anomaly(τ’_x)and shortwave heat flux(SW)anomaly exhibit westward shift biases in CESM1-CAM5 and FGOALS-s2,while the counterparts in FGOALS-g2 are relatively reasonable.The westward shift biases in representingτ’_x and the SW anomaly(SWA)are attributed to the westward-shifted precipitation anomaly(PrA).It is suggested that the mean SST cold bias over the cold tongue region is the key factor behind the westward-shift bias in simulating the El Ni?o-related PrA,which leads to the westward-shiftedτ’_x and SWA.Collectively,the aforementioned anomaly fields,including the dynamic part(τ’_x)and thermodynamic part(SWA),contribute to the westward-shift bias in simulating the El Ni?o-related SSTA.This study provides clues for understanding the ZD simulation biases of ENSO-related fields;however,further in-depth investigation with more model simulations,especially the incoming CMIP6 simulations,is still needed to fully understand the ENSO SSTA-ZD simulation bias in coupled models.展开更多
Zonal distribution and population biology of llyoplaxfrater were studied in a mangrove mudflat area of Pakistan. The crabs were collected from Korangi creek through transect and quadrat method from low tide level to h...Zonal distribution and population biology of llyoplaxfrater were studied in a mangrove mudflat area of Pakistan. The crabs were collected from Korangi creek through transect and quadrat method from low tide level to high tide level. Two transects were delimited in a mangrove area of Korangi creek （24°79′N/67°20′E）. On each transect, three 0.25 m quadrats were sampled at three tidal levels on a monthly basis during low tide periods from March 2001 to February 2002. A total of 1124 crabs were obtained, of which 482 were males and 642 were females. Density of crabs varied between 0 and 90/m^2. The density and size distribution varied and showed significant differences from low to high tide level, and were positively correlated with the percent moisture, percent organic matter and sediment grain size. The carapace width （CW） ranged from 2.5 to 11.5 mm for male and 2.5 to 11.0 mm for female and was not significantly different. The overall sex ratio did not differ significantly from the expected 1：1 throughout the year in small crabs but was significantly different in adult crabs （Z2 = 49.73） with more male crabs, Size frequency distribution showed recruitment of juvenile crabs （〈 4 mm） nearly throughout the year except during June and July. Presence of ovigerous females in all months with seasonal peaks in September, October, December and May indicates seasonal continuous breeding. Weight of egg mass increases with weight of ovigerous females and show positive linear relationship. The estimated mean diameter of egg was 2.83±0.25μm, and the average number of eggs was 3065±902.展开更多
The cooling and heating load distribution of large area air-conditioned room such as “open” offices, shopping malls and waiting rooms is usually assumed to be even in air conditioning system design. However, it is n...The cooling and heating load distribution of large area air-conditioned room such as “open” offices, shopping malls and waiting rooms is usually assumed to be even in air conditioning system design. However, it is not the case in reality, and a low efficient air conditioning system results from this assumption. A simulation and analysis of the cooling load distribution of an office building in Hong Kong with TRANSYS software is provided in this paper. A typical office is divided into 13 zones for simulation, including external zone, medial zone and internal zone in the north, the south, the east and the west respectively and a central zone, instead of 4 directional zone. The result shows there is much cooling load difference between each zone, and more attention should be paid to uneven indoor cooling and heating load distribution to further guide the design.展开更多
Senegal is a country of the Sahel. In this region, most of the populations live from agro-pastoral activities. The northern zone of Senegal is strongly influenced by river cultures. And the dynamics of the Senegal Riv...Senegal is a country of the Sahel. In this region, most of the populations live from agro-pastoral activities. The northern zone of Senegal is strongly influenced by river cultures. And the dynamics of the Senegal River are dependent on rainfall. The rainfall in the area is very closely linked to the dynamics of the atmosphere. The study of the spatio-temporal variability of rainfall in the northern region of Senegal requires quality rainfall observation data. It includes the Ferlo and the Senegal River valley, in particular the regions of Louga (department of Linguère included), Saint-Louis (departments of Dagana and Podor included) and Matam. These stations have been defined since Le Borgne (1988). The difficulty of having quality rain observation data can be resolved by using more accessible and good quality satellite data. Using satellite data, namely MSWEP, CRU, TAMSAT, ARC and PERSIANN, we showed the return of precipitation that appeared in 2000 and the unimodal cycle of precipitation in our study area. These data were validated using the correlation coefficient, the bias, the RMSE and the Nash index with observation data from the Regional Study Center for the Improvement of Adaptation to Drought (CERASS). The CRU data is then retained. Thus, this study made it possible to show the zonal distribution of rainfall in the northern zone of Senegal.展开更多
文摘Based on TOPEX/Poseidon (T/P) and ERS-1 and 2 satellite altimeter data between October 1992 and December 2000, high frequency oscillations with periods less than 150 d are analyzed and their spatial distributions are described. The ratio, instead of the energy itself, of the energy corresponding to certain frequency band from power spectrum relative to the total energy in the 20～143 d range is analyzed. The results show that the period of the most energetic oscillations in this band increases with latitude from about 1 month near the tropics to about 4 months near 30°, in agreement with the latitudinal dependency of the phase speed of westward propagating long Rossby waves,which dominate the variability in those latitudes.As a result,the global spatial distributions of the period of the dominant oscillations are largely zonal, with relatively small differences between different ocean basins. It suggests that the oscillations with periods around 60 d are mainly associated with planetary Rossby waves except the often regarded as tidal aliasing.
基金supported by the Knowledge Innovation Project of the Chinese Academy of Sciences(KZCX3-SW-330)the State Natural Science Foundation for Outstanding Personnel of China(40025103)
文摘In the purple hilly region, erosions and landslides are all serious, and it is of great scientific value and practical significance to study their formation mechanism and distribution features there. In this paper, soil micromorphological methods and techniques were used to study the erosion zonal distribution in the region. The results indicated: (1) According to erosion process, the spacial distribution zones of the erosions and landslides in the purple hilly region with different solums were divided into scouring erosion zone, transport-diffusion zone, rocks and soil turbulence zone and sediment-bury zone; (2) The soil micromorphologic taxonomic feature identifying different erosion-landslide zone were found by studying the soil micromorphology of erosive zone in purple hilly region; (3) As for the erosion–landslide formation in the region, besides the external factors, the internal factors were found more important and favorable for landslide formation through the studies on the micormorphological features of slide soil.
基金supported by the National Key Research and Development Program of China Grant No. 2019YFC1510004Natural Science Foundation of Jiangsu Province Grant No. BK20190781+2 种基金the General Program of Natural Science Foundation of Jiangsu Higher Education Institutions Grant No. 19KJB170019the open fund of State Key Laboratory of Loess and Quaternary Geology Grant No. SKLLQG1802the LASG Open Project。
文摘The simulated sea surface temperature anomaly(SSTA)over the tropical Pacific during El Ni?o–Southern Oscillation(ENSO)is investigated in three representative coupled models:CESM1-CAM5,FGOALS-s2,and FGOALS-g2.It is found that there is a significant westward shift bias in reproducing the zonal distribution(ZD)of the ENSO-related SSTA in CESM1-CAM5 and FGOALS-s2,whereas the SSTA-ZD simulated by FGOALS-g2 is relatively realistic.Through examining the SSTA-ZD during both warm and cold phases of ENSO separately,the authors reveal that the SSTA-ZD simulation bias during the ENSO cycle mainly lies in the bias during the warm phase.It is noted that both the simulated zonal wind stress anomaly(τ’_x)and shortwave heat flux(SW)anomaly exhibit westward shift biases in CESM1-CAM5 and FGOALS-s2,while the counterparts in FGOALS-g2 are relatively reasonable.The westward shift biases in representingτ’_x and the SW anomaly(SWA)are attributed to the westward-shifted precipitation anomaly(PrA).It is suggested that the mean SST cold bias over the cold tongue region is the key factor behind the westward-shift bias in simulating the El Ni?o-related PrA,which leads to the westward-shiftedτ’_x and SWA.Collectively,the aforementioned anomaly fields,including the dynamic part(τ’_x)and thermodynamic part(SWA),contribute to the westward-shift bias in simulating the El Ni?o-related SSTA.This study provides clues for understanding the ZD simulation biases of ENSO-related fields;however,further in-depth investigation with more model simulations,especially the incoming CMIP6 simulations,is still needed to fully understand the ENSO SSTA-ZD simulation bias in coupled models.
基金funded by the Pakistan Science Foundation project PSF/Res/S-KU/Envr(51) grant to NAQ
文摘Zonal distribution and population biology of llyoplaxfrater were studied in a mangrove mudflat area of Pakistan. The crabs were collected from Korangi creek through transect and quadrat method from low tide level to high tide level. Two transects were delimited in a mangrove area of Korangi creek （24°79′N/67°20′E）. On each transect, three 0.25 m quadrats were sampled at three tidal levels on a monthly basis during low tide periods from March 2001 to February 2002. A total of 1124 crabs were obtained, of which 482 were males and 642 were females. Density of crabs varied between 0 and 90/m^2. The density and size distribution varied and showed significant differences from low to high tide level, and were positively correlated with the percent moisture, percent organic matter and sediment grain size. The carapace width （CW） ranged from 2.5 to 11.5 mm for male and 2.5 to 11.0 mm for female and was not significantly different. The overall sex ratio did not differ significantly from the expected 1：1 throughout the year in small crabs but was significantly different in adult crabs （Z2 = 49.73） with more male crabs, Size frequency distribution showed recruitment of juvenile crabs （〈 4 mm） nearly throughout the year except during June and July. Presence of ovigerous females in all months with seasonal peaks in September, October, December and May indicates seasonal continuous breeding. Weight of egg mass increases with weight of ovigerous females and show positive linear relationship. The estimated mean diameter of egg was 2.83±0.25μm, and the average number of eggs was 3065±902.
文摘The cooling and heating load distribution of large area air-conditioned room such as “open” offices, shopping malls and waiting rooms is usually assumed to be even in air conditioning system design. However, it is not the case in reality, and a low efficient air conditioning system results from this assumption. A simulation and analysis of the cooling load distribution of an office building in Hong Kong with TRANSYS software is provided in this paper. A typical office is divided into 13 zones for simulation, including external zone, medial zone and internal zone in the north, the south, the east and the west respectively and a central zone, instead of 4 directional zone. The result shows there is much cooling load difference between each zone, and more attention should be paid to uneven indoor cooling and heating load distribution to further guide the design.
文摘Senegal is a country of the Sahel. In this region, most of the populations live from agro-pastoral activities. The northern zone of Senegal is strongly influenced by river cultures. And the dynamics of the Senegal River are dependent on rainfall. The rainfall in the area is very closely linked to the dynamics of the atmosphere. The study of the spatio-temporal variability of rainfall in the northern region of Senegal requires quality rainfall observation data. It includes the Ferlo and the Senegal River valley, in particular the regions of Louga (department of Linguère included), Saint-Louis (departments of Dagana and Podor included) and Matam. These stations have been defined since Le Borgne (1988). The difficulty of having quality rain observation data can be resolved by using more accessible and good quality satellite data. Using satellite data, namely MSWEP, CRU, TAMSAT, ARC and PERSIANN, we showed the return of precipitation that appeared in 2000 and the unimodal cycle of precipitation in our study area. These data were validated using the correlation coefficient, the bias, the RMSE and the Nash index with observation data from the Regional Study Center for the Improvement of Adaptation to Drought (CERASS). The CRU data is then retained. Thus, this study made it possible to show the zonal distribution of rainfall in the northern zone of Senegal.
