[Objective] The aim was to study the characteristics in VWP period characteristics in one strong rainstorm process.[Method] Based on the previous studies,the VWP product characteristics in early period of strong rains...[Objective] The aim was to study the characteristics in VWP period characteristics in one strong rainstorm process.[Method] Based on the previous studies,the VWP product characteristics in early period of strong rainstorm,during the development and the end period in Hunan Province on April 8,2008 were studied.[Result] Before the occurrence of rainstorm,the destruction of low layer 'ND' layer indicated the increase of water vapor content layer.The intrusion of cold and dry air in the middle layer led to unstable layer;during the maintaining period of rainstorm,the strong vertical shear in the low layer led to the occurrence of strong rainstorm.The cold air in the boundary layer penetrated and led the rainstorm to the most prevailing stage.There was hailstorm on the ground.Before the disappearance of rainstorm(after 17:59),the entire wind field changed into consecutive 'ND' layer and it suggested that the strong convective cloud was far away from the location of radar,and indicated the end of rainstorm.[Conclusion] The study provided reference and basis for the pre-warning of rainstorm for temporary reporter.展开更多
[Objective] The aim was to study the causes of abnormal weather in winter in 2009 and 2010 in Jinzhou. [Method] By dint of regular meteorological data and weather theory, the abnormal weather in winter from 2009 to 20...[Objective] The aim was to study the causes of abnormal weather in winter in 2009 and 2010 in Jinzhou. [Method] By dint of regular meteorological data and weather theory, the abnormal weather in winter from 2009 to 2010 in Jinzhou was expounded so as to find the reasons for abnormal climate in winter in the region. [Result] The main reason for the consecutive low temperature in winter in Jinzhou from 2009 to 2010 was the abnormal development of the Ural Mountains high-pressure ridge and strong horizontal circulation. The frequent cold air activity was the leading reason for the increase of precipitation in Jinzhou in winter; the high trough and low air torrent were the main weather system for precipitation. Convergence in the low layer was the dynamic condition for the generation of precipitation. [Conclusion] The study provided theoretical basis for the disaster prevention and mitigation work in winter.展开更多
The atmospheric boundary layer (ABL) is an important physical characteristic of the Earth's atmosphere. Compared with the typical ABL, the ABL in arid regions has distinct features and is formed by particular mecha...The atmospheric boundary layer (ABL) is an important physical characteristic of the Earth's atmosphere. Compared with the typical ABL, the ABL in arid regions has distinct features and is formed by particular mechanisms. In this paper, the depth of the diurnal and nocturnal ABLs and their related thermodynamic features of land surface processes, including net radiation, the ground-air temperature difference and sensible heat flux, under typical summer and winter conditions are discussed on the basis of comprehensive observations of the ABL and thermodynamic processes at the land surface carried out in the extreme arid zone of Dunhuang. The relationships of the ABL depth in the development and maintenance stages with these thermodynamic features are also investigated. The results show that the depth of the ABL is closely correlated with the thermodynamic features in both development and maintenance stages and more energy is consumed in the development stage. Further analysis indicates that wind velocity also affects ABL development, especially the development of a stable boundary layer in winter. Taken together, the analysis results indicate that extremely strong thermodynamic processes at the land surface are the main driving factor for the formation of a deep ABL in an arid region.展开更多
文摘[Objective] The aim was to study the characteristics in VWP period characteristics in one strong rainstorm process.[Method] Based on the previous studies,the VWP product characteristics in early period of strong rainstorm,during the development and the end period in Hunan Province on April 8,2008 were studied.[Result] Before the occurrence of rainstorm,the destruction of low layer 'ND' layer indicated the increase of water vapor content layer.The intrusion of cold and dry air in the middle layer led to unstable layer;during the maintaining period of rainstorm,the strong vertical shear in the low layer led to the occurrence of strong rainstorm.The cold air in the boundary layer penetrated and led the rainstorm to the most prevailing stage.There was hailstorm on the ground.Before the disappearance of rainstorm(after 17:59),the entire wind field changed into consecutive 'ND' layer and it suggested that the strong convective cloud was far away from the location of radar,and indicated the end of rainstorm.[Conclusion] The study provided reference and basis for the pre-warning of rainstorm for temporary reporter.
文摘[Objective] The aim was to study the causes of abnormal weather in winter in 2009 and 2010 in Jinzhou. [Method] By dint of regular meteorological data and weather theory, the abnormal weather in winter from 2009 to 2010 in Jinzhou was expounded so as to find the reasons for abnormal climate in winter in the region. [Result] The main reason for the consecutive low temperature in winter in Jinzhou from 2009 to 2010 was the abnormal development of the Ural Mountains high-pressure ridge and strong horizontal circulation. The frequent cold air activity was the leading reason for the increase of precipitation in Jinzhou in winter; the high trough and low air torrent were the main weather system for precipitation. Convergence in the low layer was the dynamic condition for the generation of precipitation. [Conclusion] The study provided theoretical basis for the disaster prevention and mitigation work in winter.
基金supported by the National Natural Science Foundation of China (Grant Nos. 40830957, 40805009)
文摘The atmospheric boundary layer (ABL) is an important physical characteristic of the Earth's atmosphere. Compared with the typical ABL, the ABL in arid regions has distinct features and is formed by particular mechanisms. In this paper, the depth of the diurnal and nocturnal ABLs and their related thermodynamic features of land surface processes, including net radiation, the ground-air temperature difference and sensible heat flux, under typical summer and winter conditions are discussed on the basis of comprehensive observations of the ABL and thermodynamic processes at the land surface carried out in the extreme arid zone of Dunhuang. The relationships of the ABL depth in the development and maintenance stages with these thermodynamic features are also investigated. The results show that the depth of the ABL is closely correlated with the thermodynamic features in both development and maintenance stages and more energy is consumed in the development stage. Further analysis indicates that wind velocity also affects ABL development, especially the development of a stable boundary layer in winter. Taken together, the analysis results indicate that extremely strong thermodynamic processes at the land surface are the main driving factor for the formation of a deep ABL in an arid region.
基金Supported by the National Basic Research Program of China(Grant No.2003CB415100)National Natural Science Foundation of China(Grant No.40575046)Natural Science Foundation of Yunnan Provence(Grant No.2004D0005M)