This investigation focuses on two mechanisms over the North Pacific connecting decadal regime shifts to regional ecosystem impacts. The physical conditions show the impacts of the atmospheric surface wind stress and t...This investigation focuses on two mechanisms over the North Pacific connecting decadal regime shifts to regional ecosystem impacts. The physical conditions show the impacts of the atmospheric surface wind stress and the sea surface temperature (SST) physical conditions on the fish landings along the west coast of California (WCC) from 1928-2008. The two mechanisms are identified by the two types of wind stress (e.g. westerly-easterly;or cyclonic-anticyclonic) anomaly over the central North Pacific which results in SST anomalies in the WCC. In both mechanism cases, the local warm (cold) SST anomaly leads to the number of fish species rising (falling) in the WCC region. In addition, the wind stress and SST anomaly pattern over the North Pacific is closely related to the intensity of the regime shifts as identified in the fish landings off the WCC.展开更多
This paper analyzes the current situation of marine ecological environment in Liaoning Province from the aspects of the environmental quality of sea areas, the situation of sewage outlets into the sea, the health stat...This paper analyzes the current situation of marine ecological environment in Liaoning Province from the aspects of the environmental quality of sea areas, the situation of sewage outlets into the sea, the health status of typical ecosystems, the types and distribution of coastline and the development and utilization of sea areas. Based on the analysis of the main problems existing in the marine ecological environment and their causes, countermeasures and suggestions are put forward to provide scientific and technological support for the protection of marine ecological environment in Liaoning Province during the "14th Five-Year Plan".展开更多
Radiation cross-calibration is an effective method to check and verify theaccuracy and stability of sensor measurements. Satellites with high radiation accuracy areused to calibrate satellites with low radiation accur...Radiation cross-calibration is an effective method to check and verify theaccuracy and stability of sensor measurements. Satellites with high radiation accuracy areused to calibrate satellites with low radiation accuracy. In order to ensure the reliability ofthe radiation cross-calibration method, we propose to obtain the gain and offset of theGaoFen-1 satellite by linear regression after the radiation cross-calibration of the satellitewith low precision and compare with the official coefficient. Finally, we get therelationship between the error in radiation cross-calibration results and side swing angle.The linear correction coefficients of each band are: 0.618, 0.625, 0.512 and 0.474. Theresults show that after the method is corrected by the linear correction coefficient, theerror caused by the side swing angle during the cross-calibration of the orbital radiation isreduced. The accuracy of radiation cross-calibration is improved, the frequency ofcalibration is improved and the requirements of remote sensing applications in the newera are adapted.展开更多
Grasslands in the Qinghai–Tibet Plateau play an important role in preserving ecological security and high biodiversity in this region.However,the distribution of the composition and structure of plant community and t...Grasslands in the Qinghai–Tibet Plateau play an important role in preserving ecological security and high biodiversity in this region.However,the distribution of the composition and structure of plant community and the mechanism by which it maintains itself in this region are still poorly understood.Here,we designed 195 grassland plots in 39 grassland sites along an approximately 1700 m elevation gradient on the Northeastern Qinghai–Tibet Plateau.We found that the grassland community height decreased significantly with increasing elevation,whereas community coverage did not significantly change.With increasing elevation,plant species richness(αdiversity)increased significantly,but the community variability(βdiversity)decreased significantly.The constrained clustering analysis suggested that theα-andβ-diversity in the grasslands transformed gradually with elevation,and that three discontinuous points(based on community structure)were observed at elevation of 3640,4252 and 4333 m.Structural equation modeling(SEM)indicated that the increase in precipitation and the decrease in temperature significantly positively influencedαdiversity,which was negatively correlated withβdiversity.These results demonstrate a quantitative-to-qualitative change in the community composition and structure along this elevational gradient on the Qinghai–Tibet Plateau.展开更多
文摘This investigation focuses on two mechanisms over the North Pacific connecting decadal regime shifts to regional ecosystem impacts. The physical conditions show the impacts of the atmospheric surface wind stress and the sea surface temperature (SST) physical conditions on the fish landings along the west coast of California (WCC) from 1928-2008. The two mechanisms are identified by the two types of wind stress (e.g. westerly-easterly;or cyclonic-anticyclonic) anomaly over the central North Pacific which results in SST anomalies in the WCC. In both mechanism cases, the local warm (cold) SST anomaly leads to the number of fish species rising (falling) in the WCC region. In addition, the wind stress and SST anomaly pattern over the North Pacific is closely related to the intensity of the regime shifts as identified in the fish landings off the WCC.
文摘This paper analyzes the current situation of marine ecological environment in Liaoning Province from the aspects of the environmental quality of sea areas, the situation of sewage outlets into the sea, the health status of typical ecosystems, the types and distribution of coastline and the development and utilization of sea areas. Based on the analysis of the main problems existing in the marine ecological environment and their causes, countermeasures and suggestions are put forward to provide scientific and technological support for the protection of marine ecological environment in Liaoning Province during the "14th Five-Year Plan".
基金funded by the National Key Research Program ofChina (No. 2016YFB0502500)Guangxi innovative Development Grand Grant (GuiKeAA18118038)+2 种基金Land Observation Satellite Supporting Platform of National civilspace infrastructureNational Natural Science Foundation of China (No. 41671345)theNanjing University of Information Science and Technology Talent Start-up Fund.
文摘Radiation cross-calibration is an effective method to check and verify theaccuracy and stability of sensor measurements. Satellites with high radiation accuracy areused to calibrate satellites with low radiation accuracy. In order to ensure the reliability ofthe radiation cross-calibration method, we propose to obtain the gain and offset of theGaoFen-1 satellite by linear regression after the radiation cross-calibration of the satellitewith low precision and compare with the official coefficient. Finally, we get therelationship between the error in radiation cross-calibration results and side swing angle.The linear correction coefficients of each band are: 0.618, 0.625, 0.512 and 0.474. Theresults show that after the method is corrected by the linear correction coefficient, theerror caused by the side swing angle during the cross-calibration of the orbital radiation isreduced. The accuracy of radiation cross-calibration is improved, the frequency ofcalibration is improved and the requirements of remote sensing applications in the newera are adapted.
基金National Natural Science Foundation of China(31901172)Science and Technology Project of Qinghai Provincial Department of Transportation(2019-07).
文摘Grasslands in the Qinghai–Tibet Plateau play an important role in preserving ecological security and high biodiversity in this region.However,the distribution of the composition and structure of plant community and the mechanism by which it maintains itself in this region are still poorly understood.Here,we designed 195 grassland plots in 39 grassland sites along an approximately 1700 m elevation gradient on the Northeastern Qinghai–Tibet Plateau.We found that the grassland community height decreased significantly with increasing elevation,whereas community coverage did not significantly change.With increasing elevation,plant species richness(αdiversity)increased significantly,but the community variability(βdiversity)decreased significantly.The constrained clustering analysis suggested that theα-andβ-diversity in the grasslands transformed gradually with elevation,and that three discontinuous points(based on community structure)were observed at elevation of 3640,4252 and 4333 m.Structural equation modeling(SEM)indicated that the increase in precipitation and the decrease in temperature significantly positively influencedαdiversity,which was negatively correlated withβdiversity.These results demonstrate a quantitative-to-qualitative change in the community composition and structure along this elevational gradient on the Qinghai–Tibet Plateau.
