Based on the monitoring data of cloud-to-ground( CG) lightning positioning network and Doppler weather radar as well as MICAPS1°× 1° objective analysis field,a squall line process outside of the subtrop...Based on the monitoring data of cloud-to-ground( CG) lightning positioning network and Doppler weather radar as well as MICAPS1°× 1° objective analysis field,a squall line process outside of the subtropical high in low-latitude plateau on May 7,2010 was analyzed. The results showed that wind direction shear between low and high levels and low-level convergence zones provided favorable circulation background for the strong thunderstorm process,while high energy and high humidity,strong thermal instability and ascending motion at low and middle levels offered beneficial environmental conditions for the formation of the thunderstorm. 9 620 return strokes of cloud-to-ground lightning were monitored by the lightning positioning network,and cloud-to-ground lightning was distributed like bands between 584 and 586 hP a. The occurrence of cloud-to-ground lightning was mainly related to echo top and echo intensity at-10 ℃ stratification height,and it mainly appeared in zones where echo top height was larger than 13 km and echo intensity at-10 ℃ stratification height was 35-40 dB Z. Wind convergence and maintaining of high radial velocity were favorable for the development of convective echoes and occurrence of cloud-to-ground lightning.展开更多
目的分析2019—2020监测年度,中国大陆地区流感暴发疫情的流行病学和病原学特征,为科学制定流感疫情防控政策提供参考依据。方法收集2019年4月1日至2020年3月29日"突发公共卫生事件管理信息系统"和"中国流感监测信息系统...目的分析2019—2020监测年度,中国大陆地区流感暴发疫情的流行病学和病原学特征,为科学制定流感疫情防控政策提供参考依据。方法收集2019年4月1日至2020年3月29日"突发公共卫生事件管理信息系统"和"中国流感监测信息系统"报告的2019—2020监测年度流感和流感样病例(influenza like illness,ILI)暴发疫情数据,对2019—2020年流感监测年度中国大陆流感和ILI暴发疫情的特征进行描述性分析。结果中国大陆地区2019—2020监测年度共报告流感和ILI暴发疫情3864起,其中流感暴发疫情为3675起(占95.11%);南、北方片区在2019年4月至5月达到一个小高峰,随后逐渐下降,南方地区于7月至9月呈低水平流行,北方地区于6月至10月呈低水平流行。随后疫情呈上升趋势,南、北方片区全年ILI暴发疫情最高峰均出现在2019年12月(分别是1731起和467起),自2020年1月底开始,迅速下降至极低水平。除2019年8月外,该监测年度各月份南方片区流感暴发疫情起数均高于北方片区。各种类型学校共报告暴发疫情起数为3804起,占比为98.45%,中、小学校为暴发疫情报告的最主要场所,共报告暴发疫情3382起(87.53%)。结论2019—2020监测年度南方地区流感暴发疫情高于北方地区,呈明显的季节性,秋冬季为暴发疫情的高峰期,应加强学校的流感防控工作,减少聚集性暴发疫情的发生。展开更多
基金Supported by National Natural Science Foundation of China(No.41305002)Science and Technology Project of Yunnan Province(No.2014RA002,2016RA096)
文摘Based on the monitoring data of cloud-to-ground( CG) lightning positioning network and Doppler weather radar as well as MICAPS1°× 1° objective analysis field,a squall line process outside of the subtropical high in low-latitude plateau on May 7,2010 was analyzed. The results showed that wind direction shear between low and high levels and low-level convergence zones provided favorable circulation background for the strong thunderstorm process,while high energy and high humidity,strong thermal instability and ascending motion at low and middle levels offered beneficial environmental conditions for the formation of the thunderstorm. 9 620 return strokes of cloud-to-ground lightning were monitored by the lightning positioning network,and cloud-to-ground lightning was distributed like bands between 584 and 586 hP a. The occurrence of cloud-to-ground lightning was mainly related to echo top and echo intensity at-10 ℃ stratification height,and it mainly appeared in zones where echo top height was larger than 13 km and echo intensity at-10 ℃ stratification height was 35-40 dB Z. Wind convergence and maintaining of high radial velocity were favorable for the development of convective echoes and occurrence of cloud-to-ground lightning.
文摘目的分析2019—2020监测年度,中国大陆地区流感暴发疫情的流行病学和病原学特征,为科学制定流感疫情防控政策提供参考依据。方法收集2019年4月1日至2020年3月29日"突发公共卫生事件管理信息系统"和"中国流感监测信息系统"报告的2019—2020监测年度流感和流感样病例(influenza like illness,ILI)暴发疫情数据,对2019—2020年流感监测年度中国大陆流感和ILI暴发疫情的特征进行描述性分析。结果中国大陆地区2019—2020监测年度共报告流感和ILI暴发疫情3864起,其中流感暴发疫情为3675起(占95.11%);南、北方片区在2019年4月至5月达到一个小高峰,随后逐渐下降,南方地区于7月至9月呈低水平流行,北方地区于6月至10月呈低水平流行。随后疫情呈上升趋势,南、北方片区全年ILI暴发疫情最高峰均出现在2019年12月(分别是1731起和467起),自2020年1月底开始,迅速下降至极低水平。除2019年8月外,该监测年度各月份南方片区流感暴发疫情起数均高于北方片区。各种类型学校共报告暴发疫情起数为3804起,占比为98.45%,中、小学校为暴发疫情报告的最主要场所,共报告暴发疫情3382起(87.53%)。结论2019—2020监测年度南方地区流感暴发疫情高于北方地区,呈明显的季节性,秋冬季为暴发疫情的高峰期,应加强学校的流感防控工作,减少聚集性暴发疫情的发生。
