On May 20 th 2007, a brief but severe downpour rainstorm occurred in the coastal areas of Maoming and Yangjiang with rainfall of 115 mm per hour. Data from NCEP/NCAR reanalysis with 1°×1° resolution, Do...On May 20 th 2007, a brief but severe downpour rainstorm occurred in the coastal areas of Maoming and Yangjiang with rainfall of 115 mm per hour. Data from NCEP/NCAR reanalysis with 1°×1° resolution, Doppler weather radar, conventional surface observations, high-altitude radiosonde and wind profiler radar were used to analyze characteristics and contributions of synoptic scale and mesoscale systems during this torrential rainstorm. The results showed that:(1) the storm was caused by a quasi-linear mesoscale convective system(MCS) and the slow-movement of this system was the primary trigger of the torrential downpour;(2) water vapor was abundant, nearly saturated and in steady state throughout the atmosphere before the storm; intrusion of the weak dry and cold air in the middle level and a striking "dry above and wet below " structure had increased the atmospheric instability;(3) low-level southwesterly airflow from a low pressure(trough) at the Beibu Gulf provided abundant water vapor at the onset of the rainstorm; a deep dry layer was formed by dry and cold air behind the high-level trough, which facilitated latent heat release;upper-level divergence and low-level convergence circulations also provided vertical uplift for warm and moist air at the lower level;(4) Topography only played a minor role as the MCS developed and strengthened over relatively flat coastal terrain. Low level density flow induced by convection triggered new convective cell generation at the leading edge of the convective system, thereby playing a key role in the change of temperature gradient at lower layers, and resulting in strengthening atmospheric instability.展开更多
For the first time, the separating issues of the Tenir-Too mountains into sectors in contrast to the accepted schemes of physical geography as a province and sub-province were discussed. Since the term province is mor...For the first time, the separating issues of the Tenir-Too mountains into sectors in contrast to the accepted schemes of physical geography as a province and sub-province were discussed. Since the term province is more acceptable in political science than in physical geography, the main factors in the process of sector formation were determined. The purpose of this article is not only to describe the high altitudes of the Tenir-Too mountains, but theoretically substantiate their formation, ecological and genetic features, and distribution patterns. Until today the Tenir-Too mountain area is not divided into sectors and subsectors with significant changes to the stencil scheme, which has been used to date in the physical geographical zoning. Research methods in this work are based on the recent study materials collected from meteorological stations of Tenir-Too region. Hypsometric and topographic maps were used to identify high altitude ranges, and climatic factors were separated by zones. Plant species and genus divisions were identified. In some areas of the Tenir-Too the range of altitudes along the routes was studied.展开更多
基金Guangdong Province Science and Technology Project(2017B020244002)National key basic research and development plan(973 plan)project"Typhoon fine structure multi-source data analysis theory and method research"(2015CB452802)+2 种基金National Program on Key Basic Research Project(2015CB452801)National Natural Science Foundation project"Observation and Assimilation Technology of Batch Variational Data and Its Application"(41475102)National Natural Science Foundation of China(41275025)
文摘On May 20 th 2007, a brief but severe downpour rainstorm occurred in the coastal areas of Maoming and Yangjiang with rainfall of 115 mm per hour. Data from NCEP/NCAR reanalysis with 1°×1° resolution, Doppler weather radar, conventional surface observations, high-altitude radiosonde and wind profiler radar were used to analyze characteristics and contributions of synoptic scale and mesoscale systems during this torrential rainstorm. The results showed that:(1) the storm was caused by a quasi-linear mesoscale convective system(MCS) and the slow-movement of this system was the primary trigger of the torrential downpour;(2) water vapor was abundant, nearly saturated and in steady state throughout the atmosphere before the storm; intrusion of the weak dry and cold air in the middle level and a striking "dry above and wet below " structure had increased the atmospheric instability;(3) low-level southwesterly airflow from a low pressure(trough) at the Beibu Gulf provided abundant water vapor at the onset of the rainstorm; a deep dry layer was formed by dry and cold air behind the high-level trough, which facilitated latent heat release;upper-level divergence and low-level convergence circulations also provided vertical uplift for warm and moist air at the lower level;(4) Topography only played a minor role as the MCS developed and strengthened over relatively flat coastal terrain. Low level density flow induced by convection triggered new convective cell generation at the leading edge of the convective system, thereby playing a key role in the change of temperature gradient at lower layers, and resulting in strengthening atmospheric instability.
文摘For the first time, the separating issues of the Tenir-Too mountains into sectors in contrast to the accepted schemes of physical geography as a province and sub-province were discussed. Since the term province is more acceptable in political science than in physical geography, the main factors in the process of sector formation were determined. The purpose of this article is not only to describe the high altitudes of the Tenir-Too mountains, but theoretically substantiate their formation, ecological and genetic features, and distribution patterns. Until today the Tenir-Too mountain area is not divided into sectors and subsectors with significant changes to the stencil scheme, which has been used to date in the physical geographical zoning. Research methods in this work are based on the recent study materials collected from meteorological stations of Tenir-Too region. Hypsometric and topographic maps were used to identify high altitude ranges, and climatic factors were separated by zones. Plant species and genus divisions were identified. In some areas of the Tenir-Too the range of altitudes along the routes was studied.
