A squall line on 14 June 2009 in the provinces of Jiangsu and Anhui was well simulated using the Advanced Regional Prediction System （ARPS） model. Based on high resolution spatial and temporal data, a detailed analy...A squall line on 14 June 2009 in the provinces of Jiangsu and Anhui was well simulated using the Advanced Regional Prediction System （ARPS） model. Based on high resolution spatial and temporal data, a detailed analysis of the structural features and propagation mechanisms of the squall line was conducted. The dynamic and thermodynamic structural charac- teristics and their causes were analyzed in detail. Unbalanced flows were found to play a key role in initiating gravity waves during the squall line＇s development. The spread and development of the gravity waves were sustained by convection in the wave-CISK process. The squall line＇s propagation and development mainly relied on the combined effect of gravity waves at the midlevel and cold outflow along the gust front. New cells were continuously forced by the cold pool outflow and were enhanced and lifted by the intense upward motion. At a particular phase, the new cells merged with the updraft of the gravity waves, leading to an intense updraft that strengthened the squall line.展开更多
The grain-size of suspended particulate matter （SPM） in the Huanghe Estuary and its adjacent sea area was investigated with an in situ laser particle size analyzer （LISST-100） in November 2006.The spatial distribu...The grain-size of suspended particulate matter （SPM） in the Huanghe Estuary and its adjacent sea area was investigated with an in situ laser particle size analyzer （LISST-100） in November 2006.The spatial distribution of the grain-size parameters was very complicated.The results show that （1） the mean particle size of SPM ranged from 3.00Φ to 6.41Φ,with an average value of 4.66Φ;（2） the frequency distribution patterns of the SPM grain-size showed three different types,which were mono-mode,dual-mode and tri-mode,respectively;（3） C-M chart suggested that the transportation-processes of the SPM not only included suspended mode,but also the bed load transportation mode.The bed load transportation mode mainly occurred at the bottom layer.The characteristics and space distribution of SPM grain-size might be mainly controlled by sediment discharge of the Huanghe River,hydrodynamics condition,surface sediment types,and biological process within the study area.展开更多
By using ERA-Interim data, the temperature anomaly of the freezing rain and snowstorm event that occurred from Ii to 22 January 2008 in southern China was analyzed. During this period, diabatic heating and temperature...By using ERA-Interim data, the temperature anomaly of the freezing rain and snowstorm event that occurred from Ii to 22 January 2008 in southern China was analyzed. During this period, diabatic heating and temperature advection caused the temperature to increase anomalously over the Tibetan Plateau. The anomalously high temperature moving from the Tibetan Plateau to southern Chin.a played several roles. First, the upper-level subtropical jet over China was split into two parts in the north-south direction, which affected the development of freezing rain in southern China; second, a ridge formed because of the warmer air moving to China, which hindered the transport of cold air from its upstream blocking high, forced the cold air to gather behind the ridge, and facilitated the severe cold air outbreak in the later period of the event; third, an inversion layer formed because of the lower-level cold air and upper-level warmer air over southern China, which was conducive to the development of the event over southern China; and finally, because of the temperature anomaly, opposite wind directions appeared at the lower levels （below 700 hPa）, which helped transport of warm-moist and cold-dry air to the event area.展开更多
基金supported by the National Basic Research Program of China (Grant No. 2013CB 430105)the Key Program of the Chinese Academy of Sciences (Grant No. KZZD-EW-05)+1 种基金the project of CAMS (Chinese Academy of Meteorological Sciences) (Grant No. 2011LASWB15)the National Natural Sciences Foundation of China (Grant No. 41175060)
文摘A squall line on 14 June 2009 in the provinces of Jiangsu and Anhui was well simulated using the Advanced Regional Prediction System （ARPS） model. Based on high resolution spatial and temporal data, a detailed analysis of the structural features and propagation mechanisms of the squall line was conducted. The dynamic and thermodynamic structural charac- teristics and their causes were analyzed in detail. Unbalanced flows were found to play a key role in initiating gravity waves during the squall line＇s development. The spread and development of the gravity waves were sustained by convection in the wave-CISK process. The squall line＇s propagation and development mainly relied on the combined effect of gravity waves at the midlevel and cold outflow along the gust front. New cells were continuously forced by the cold pool outflow and were enhanced and lifted by the intense upward motion. At a particular phase, the new cells merged with the updraft of the gravity waves, leading to an intense updraft that strengthened the squall line.
基金The Ministry of Science and Technology of China under contract No. 2005CB422304the National Natural Science Foundation of China under contract No. 40976020
文摘The grain-size of suspended particulate matter （SPM） in the Huanghe Estuary and its adjacent sea area was investigated with an in situ laser particle size analyzer （LISST-100） in November 2006.The spatial distribution of the grain-size parameters was very complicated.The results show that （1） the mean particle size of SPM ranged from 3.00Φ to 6.41Φ,with an average value of 4.66Φ;（2） the frequency distribution patterns of the SPM grain-size showed three different types,which were mono-mode,dual-mode and tri-mode,respectively;（3） C-M chart suggested that the transportation-processes of the SPM not only included suspended mode,but also the bed load transportation mode.The bed load transportation mode mainly occurred at the bottom layer.The characteristics and space distribution of SPM grain-size might be mainly controlled by sediment discharge of the Huanghe River,hydrodynamics condition,surface sediment types,and biological process within the study area.
基金Supported by the National Natural Science Foundation of China(91437215 and 41405055)National Key Basic Research and Development(973)Program of China(2012CB417201)
文摘By using ERA-Interim data, the temperature anomaly of the freezing rain and snowstorm event that occurred from Ii to 22 January 2008 in southern China was analyzed. During this period, diabatic heating and temperature advection caused the temperature to increase anomalously over the Tibetan Plateau. The anomalously high temperature moving from the Tibetan Plateau to southern Chin.a played several roles. First, the upper-level subtropical jet over China was split into two parts in the north-south direction, which affected the development of freezing rain in southern China; second, a ridge formed because of the warmer air moving to China, which hindered the transport of cold air from its upstream blocking high, forced the cold air to gather behind the ridge, and facilitated the severe cold air outbreak in the later period of the event; third, an inversion layer formed because of the lower-level cold air and upper-level warmer air over southern China, which was conducive to the development of the event over southern China; and finally, because of the temperature anomaly, opposite wind directions appeared at the lower levels （below 700 hPa）, which helped transport of warm-moist and cold-dry air to the event area.
