利用云南省2006-2007年多普勒雷达产品及冰雹灾情资料,选取冰雹直径大于5 mm的22次灾害性冰雹天气过程进行分型统计。结果表明:云南春季南支槽影响型雹灾回波水平尺度大,回波核高度高,易出现典型钩状回波、弓形回波、"V"型缺...利用云南省2006-2007年多普勒雷达产品及冰雹灾情资料,选取冰雹直径大于5 mm的22次灾害性冰雹天气过程进行分型统计。结果表明:云南春季南支槽影响型雹灾回波水平尺度大,回波核高度高,易出现典型钩状回波、弓形回波、"V"型缺口、弱回波区、悬垂结构等典型的超级单体特征;夏季中纬度西风槽影响型和减弱的西行台风影响型雹灾水平尺度、回波形状和垂直伸展高度均不如前者典型,但易出现三体散射现象。春季南支槽影响型雹灾的联合预警指标有回波强度大于50 d Bz、回波核高于6 km、30 d Bz水平尺度大于30 km、WER大于4 km、出现典型超级单体特征、速度场出现风场辐合、气旋性辐合、逆风区等、VIL出现明显跃增(最好大于30 kg/m2)、冰雹概率大于100%、出现中尺度气旋;夏季中纬度西风槽影响型和减弱的西行台风影响型雹灾的联合预警指标有回波强度大于50 d Bz、回波核高于4 km、30 d Bz水平尺度大于20 km、速度场出现风场辐合、气旋性辐合、逆风区等、出现三体散射现象、VIL出现明显跃增(最好大于30 kg/m2)、冰雹概率大于80%、出现中尺度气旋。展开更多
Intensive field experiment is an important approach to obtain microphysical information about clouds and precipitation. From 1 July to 31 August 2014, the third Tibetan Plateau Atmospheric Science Experiment was carri...Intensive field experiment is an important approach to obtain microphysical information about clouds and precipitation. From 1 July to 31 August 2014, the third Tibetan Plateau Atmospheric Science Experiment was carried out and comprehensive measurements of water vapor, clouds, and precipitation were conducted at Naqu. The most advanced radars in China, such as Ka-band millimeter-wave cloud radar, Ku-band micro-rain radar, C-band continuous-wave radar and lidar, and microwave radiometer and disdrometer were deployed to observe high spatial-temporal vertical structures of clouds and precipitation. The C-band dual- linear polarization radar was coordinated with the China new generation weather radar to constitute a dual- Doppler radar system for the measurements of three-dimensional wind fields within convective precipitations and the structure and evolution of hydrometeors related to precipitation process. Based on the radar measurements in this experiment, the diurnal variations of several important cloud properties were analyzed, including cloud top and base, cloud depth, cloud cover, number of cloud layers, and their vertical structures during summertime over Naqu. The features of reflectivity, velocity, and depolarization ratio for different types of clouds observed by cloud radar are discussed. The results indicate that the cloud properties were successfully measured by using various radars in this field experiment. During the summertime over Naqu, most of the clouds were located above 6 km and below 4 km above ground level. Statistical analysis shows that total amounts of clouds, the top of high-level clouds, and cloud depth, all demonstrated a distinct diurnal variation. Few clouds formed at 1000 LST （local standard time）, whereas large amounts of clouds formed at 2000 LST. Newly formed cumulus and stratus clouds were often found at 3-km height, where there existed significant updrafts. Deep convection reached up to 16.5 km （21 km above the mean sea level）, and updrafts and downdrafts coexisted in t展开更多
利用NCEP再分析资料、探空资料、闪电定位资料和南京、常州多普勒雷达资料,通过对比分析南京2012年2月22日春季雷暴和2011年8月10日夏季雷暴两次过程,研究不同季节影响雷暴发生的大气结构以及强弱雷暴地闪特征的差异。结果表明:风矢位温...利用NCEP再分析资料、探空资料、闪电定位资料和南京、常州多普勒雷达资料,通过对比分析南京2012年2月22日春季雷暴和2011年8月10日夏季雷暴两次过程,研究不同季节影响雷暴发生的大气结构以及强弱雷暴地闪特征的差异。结果表明:风矢位温(V-3θ)图揭示的大气动力热力水汽特征能够为雷暴的潜势预报提供先兆信息。两者相较而言,春季雷暴的动力抬升作用明显;夏季雷暴主要由热对流引起,对流层上层的动力抽吸作用不明显。春季弱雷暴正地闪在总地闪中所占比例较高。无论春季弱雷暴还是夏季强雷暴,地闪落点与辐合区对应关系明显,且地闪的落点也与雷达反射率因子有较好的对应关系:地闪主要分布在强回波区(大于40 d Bz)及其外围区域。但在较强雷暴云的发展阶段,地闪多发生在风暴体伸展方向的一侧,具有引导雷达回波移动的作用,夏季强雷暴地闪簇集在垂直风切变区域。展开更多
文摘利用云南省2006-2007年多普勒雷达产品及冰雹灾情资料,选取冰雹直径大于5 mm的22次灾害性冰雹天气过程进行分型统计。结果表明:云南春季南支槽影响型雹灾回波水平尺度大,回波核高度高,易出现典型钩状回波、弓形回波、"V"型缺口、弱回波区、悬垂结构等典型的超级单体特征;夏季中纬度西风槽影响型和减弱的西行台风影响型雹灾水平尺度、回波形状和垂直伸展高度均不如前者典型,但易出现三体散射现象。春季南支槽影响型雹灾的联合预警指标有回波强度大于50 d Bz、回波核高于6 km、30 d Bz水平尺度大于30 km、WER大于4 km、出现典型超级单体特征、速度场出现风场辐合、气旋性辐合、逆风区等、VIL出现明显跃增(最好大于30 kg/m2)、冰雹概率大于100%、出现中尺度气旋;夏季中纬度西风槽影响型和减弱的西行台风影响型雹灾的联合预警指标有回波强度大于50 d Bz、回波核高于4 km、30 d Bz水平尺度大于20 km、速度场出现风场辐合、气旋性辐合、逆风区等、出现三体散射现象、VIL出现明显跃增(最好大于30 kg/m2)、冰雹概率大于80%、出现中尺度气旋。
基金Supported by the China Meteorological Administration Special Public Welfare Research Fund(GYHY201406001)National Key Basic Research and Development(973)Program of China(2012CB417202)National Natural Science Foundation of China(91337103 and 41175038)
文摘Intensive field experiment is an important approach to obtain microphysical information about clouds and precipitation. From 1 July to 31 August 2014, the third Tibetan Plateau Atmospheric Science Experiment was carried out and comprehensive measurements of water vapor, clouds, and precipitation were conducted at Naqu. The most advanced radars in China, such as Ka-band millimeter-wave cloud radar, Ku-band micro-rain radar, C-band continuous-wave radar and lidar, and microwave radiometer and disdrometer were deployed to observe high spatial-temporal vertical structures of clouds and precipitation. The C-band dual- linear polarization radar was coordinated with the China new generation weather radar to constitute a dual- Doppler radar system for the measurements of three-dimensional wind fields within convective precipitations and the structure and evolution of hydrometeors related to precipitation process. Based on the radar measurements in this experiment, the diurnal variations of several important cloud properties were analyzed, including cloud top and base, cloud depth, cloud cover, number of cloud layers, and their vertical structures during summertime over Naqu. The features of reflectivity, velocity, and depolarization ratio for different types of clouds observed by cloud radar are discussed. The results indicate that the cloud properties were successfully measured by using various radars in this field experiment. During the summertime over Naqu, most of the clouds were located above 6 km and below 4 km above ground level. Statistical analysis shows that total amounts of clouds, the top of high-level clouds, and cloud depth, all demonstrated a distinct diurnal variation. Few clouds formed at 1000 LST （local standard time）, whereas large amounts of clouds formed at 2000 LST. Newly formed cumulus and stratus clouds were often found at 3-km height, where there existed significant updrafts. Deep convection reached up to 16.5 km （21 km above the mean sea level）, and updrafts and downdrafts coexisted in t
文摘利用NCEP再分析资料、探空资料、闪电定位资料和南京、常州多普勒雷达资料,通过对比分析南京2012年2月22日春季雷暴和2011年8月10日夏季雷暴两次过程,研究不同季节影响雷暴发生的大气结构以及强弱雷暴地闪特征的差异。结果表明:风矢位温(V-3θ)图揭示的大气动力热力水汽特征能够为雷暴的潜势预报提供先兆信息。两者相较而言,春季雷暴的动力抬升作用明显;夏季雷暴主要由热对流引起,对流层上层的动力抽吸作用不明显。春季弱雷暴正地闪在总地闪中所占比例较高。无论春季弱雷暴还是夏季强雷暴,地闪落点与辐合区对应关系明显,且地闪的落点也与雷达反射率因子有较好的对应关系:地闪主要分布在强回波区(大于40 d Bz)及其外围区域。但在较强雷暴云的发展阶段,地闪多发生在风暴体伸展方向的一侧,具有引导雷达回波移动的作用,夏季强雷暴地闪簇集在垂直风切变区域。
