Effect of different cold air intensities and their lagged effects on outpatient visits for respiratory illnesses in Handan in different seasons

本文利用2016年到2019年邯郸市气象要素和呼吸系统疾病门诊数据,分析了不同季节不同强度的冷空气过程及其对呼吸系统疾病的影响,结果显示:尽管呼吸系统疾病在冬季高发,夏季最低,但冷空气对呼吸系统疾病的影响在夏,春季最大,就诊人数分别在冷空气日后两天和五天增加18.4%和13.3%,而冬季就诊人数在冷空气日后三天仅增加3.2%.冷空气对疾病影响的滞后时间在夏,秋和冬季随冷空气强度的增加而减少,而春季的滞后时间总是很长.这些发现可为科学应对气候异常导致的人群健康风险提供针对性依据.

Analysis on "96. 8" Heavy Rainstorm Process in Handan

[ ObjEtive] The research aimed to analyze ＂96.8＂ heavy rainstorm process causing flood disaster in Handan. [ Method] Based on ac- tual situation data, satellite cloud data and NCEP reanalysis data in the first dekad of August in 1996, ＂96.8＂ heavy rainstorm process causing flood disaster in Handan was analyzed to understand occurrence reason of the flood disaster. [ Result] Two meso-scale convective cloud clusters which developed and went north in turn caused ＂96.8＂ heavy rainstorm in Handan. Typhoon and inverted trough were main weather systems induced flood disaster in Handan. In going north process of the low-level jet, due to blocking of the subtropical high, water vapor and energy accumulated in Handan, providing material basis for formation of the heavy rainstorm. Development and eastward movement of the short-wave trough at middle lati- tude and continuous invasion of the reflux weak cold air at the low layer were direct reason for triggering generation and development of the convec- tive cloud cluster, and further causing continuous rainstorm. Wet layer over the rainstorm zone was deep and thick. Meridional distribution of the wet zone was wider than latitudinal distribution. South China Sea and Bay of Bengal were water vapor sources for the rainstorm zone. In the whole rain- storm period, it was convergence at low layer and divergence at high layer in the rainstorm zone. It was positive vorticity at low layer and negative vorticity at high layer. Precipitation intensity changed as convergence and divergence. Rainstorm zone had strong ascending motion. As strengthe- ning and uplifting of the ascending motion strong center, strong precipitation also strengthened. Rainstorm center was near the biggest vertical ve- locity center. Strong precipitation changed as vertical ascending motion. [ Conclmion] The research provided scientific basis for disaster prevention and reduction and decision-making service.

Thoughts on the Development of Meteorological Wechat Public Platform

As a modern communication software, Wechat is favored by many young people due to its fast spreading, large influence and numerous customers. In the process, the establishment of meteorological Wechat public platform could play the effects of disaster prevention and mitigation and improving service capacity without changing the advantages of Wechat. In view of this, by analyzing Wetchat and its public platform, main functions of meteorological Wechat public platform are expounded, and development prospects of the public platform are cleared from multiple perspectives.

Research on Characteristics of Atmospheric Pollution and Meteorological Condition in South of Northern China

Taking Handan City (the south of Northern China) as an example, and making use of the environmentally friendly materials of Handan Environmental Monitor Station in 2013-2014, the surface observational data of Handan Meteorological Station and the sounding data of Xingtai station, combined with the integrated analysis of numerical prediction and simulation, this paper shows that, in 2014, the air quality improved;the emission-reduction effect was significant;the days of heavy pollution decreased;and the days up to the standard increased;the annual average concentration of pollutants PM2.5 and PM10 in the whole city showed a decreasing tendency compared to the same period of last year. In 2014, there were a total of 9 weather processes of heavy pollution lasting more than 3 days and the duration was significantly shorter than that in 2013, which indicated that effective emission-reduction measures significantly shortened the duration of weather processes of heavy pollution. The comprehensive analysis of meteorological conditions, such as the days of light wind, wind speed, wind frequency, PM2.5 concentration at different wind directions, the thickness and intensity of the inversion layer, and the height of the mixed layer, showed that, compared with the same period in 2013, the general meteorological conditions of air pollutant dispersion were basically flat and slightly disadvantageous in 2014. Handan municipal government increased the intensity of the prevention and control of air pollution in 2014, promulgated and adopted a series of air pollution control policies and emission-reduction control measures, and achieved some results, especially the emission-reduction measures during the APEC meeting which were obviously effective.

Deformation characteristics of the ‘7.20' heavy rainfall event in North China

本文通过将变形引入到非均匀饱和湿大气动力框架下的非地转Q矢量中验证了变形对驱动与强降水有关的垂直运动中的重要性。进一步,为了将变形更好地应用于降水诊断,将变形与其他动热力因子结合,提出位势形变参数,并推导了其倾向方程。研究表明,位势形变与强降水有密切相关性,其包含与降水有关的关键动热力要素,从而使位势形变能够抓住强降水产生的动热力学要点,对降水有良好指示追踪意义。

青藏高原东部暴雨的中尺度有效位能收支分析

针对2018年7月10-11日青藏高原东部一次暴雨过程,利用模式模拟资料分析了有效位能分布特征,成因及其对降水发展演变的影响.结果表明,有效位能主要分布在对流层低层4km以下和高层8-14km,高层有效位能和降水有更好的对应性西北冷平流和降水粒子下落的蒸发作用是低层有效位能高值中心的主要成因,而降水过程释放潜热带来的热力扰动叠加高原大地形造成的位温扰动是导致高层有效位能高值的主要原因.有效位能收支分析表明,有效位能的通量输送项以及与动能间的转换项是主要源汇项.低层有效位能的经向通量输送和动能向有效位能的转化补给了有效位能的耗散;高层有效位能向垂直动能转化增强垂直运动是促进降水发展演变的主要因素.高层有效位能与垂直运动之间的正反馈过程使得两者相关性较强;低层较长时间内均存在垂直动能向有效位能的转化,削弱了垂直运动,而西北冷平流使得低层有效位能有增强的趋势,因此二者相关性较弱.

A Diagnostic Analysis of the Simulated Structure of a Meiyu Front System in 1999

A numerical simulation of a torrential rain event occurring in the Jiang-Huai Valley of China from 22-24 June 1999 is performed and analyzed by using the PSU/NCAR MM5 mesoscale non-hydrostatic model. The high-resolution model output data are utilized to diagnose the double front structure, and the distributions of potential temperature, equivalent potential temperature, and specific humidity in the vicinity of the Meiyu Front System （MYFS） in the Jiang-Huai Valley. The results show that both the potential temperature gradient and the specific humidity gradient have important impacts on the two strong equivalent potential temperature gradient zones associated with the double front structure of the MYFS, but the latter （moisture gradient） is more important. In addition, the tendency equation of specific humidity gradient is theoretically derived. It shows that variations of the specific humidity gradient are related to the advection, convergence/divergence, horizontal and vertical vorticities （secondary circulation） effects and the gradient of water vapor source/sink. As an example, the budget of the meridional component of the tendency equation is selected and diagnosed by using the above model simulation data of the torrential rain event. It is shown that the variation of the specific humidity gradient averaged throughout the simulation is mainly controlled by the convergence/divergence effect, the secondary circulation effect associated with the horizontal vorticities, and the water vapor source/sink effect. Since the water vapor source/sink is often formed from the phase change processes of water vapor in the air and thus directly associated with cloud and precipitation microphysics processes, the variation of the specific humidity gradient is closely related with cloud and precipitation microphysics and the distribution, development and evolution of cloud and rainfall systems. The double front structure of the MYFS provides an advantageous environmental condition for the development and movement of the mesoscale torrential rain system nearby. In turn, the development of the torrential rain exerts a signifiant impact on the MYFS through changing the thermal and moisture distributions.