利用GCM模式对全球雷电活动的模拟分析

将修正的参数化方案嵌套入美国马里兰大学海-陆-气研究中心的全球大气环流谱模式(COLAGCM),建立了可用于全球雷电活动模拟与估测的模式系统.通过对模式输出与实况资料的对比,检验其气候模拟性能.虽然模式的分辨率较低但经过较长时间积分,仍可再现实况资料的主要特征.性能良好,计算稳定,且因时间步长较大可大大节省机时.耦合模式系统经长时间的积分后,模拟的多年平均的全球雷电频次时空分布及变化与观测分析较一致.全球范围内每秒钟平均有79次的雷电发生,陆海比为12.2.多发生在北半球夏季且具明显的季节变化特征.     

基于多源监测数据的雷电预警方法

以浙江省气象台已经业务运行多年的基于雷达数据的雷电预警产品(预警时效为60min,分辨率为1km×1km,4个预警等级)为基础,融合闪电定位系统数据和大气电场数据,提出一种基于多源监测数据的雷电预警方法。使用2018年的观测数据进行预警效果检验,结果表明:雷电预警的漏报率为31.89%,空报率为30.54%,临界成功指数为60.53%,比使用单一监测数据的雷电预警效果有所提高。由此可见,该雷电预警方法对浙江省雷电天气的预警具有参考价值和指示意义。     

河北省雷电灾害事件特征分析

为了解河北省雷电灾害事件的时空分布、行业分布、经济损失及人员伤亡等,对2006—2017年(不包括2013、2016年)河北省雷电灾害事件资料进行统计分析。结果表明:河北省近10 a雷电灾害事件呈逐年波动递减的趋势,主要发生在6—8月,占全年雷电灾害事件总数的81.34%,唐山、保定和石家庄市为雷电灾害事件的高发区。雷电灾害事件最为严重的是电力行业达382起,人员伤亡事故主要发生在乡村。     

地闪连续电流特征的统计分析

利用高时间分辨的闪电电场变化资料,统计分析了我国甘肃和广东地区闪连续电流特征。结果表明：在甘肃中川地区１０３产次地闪中,带有连续电流的地闪有４９．５％,连续电流的平均持续时间为８８．９ｍｓ;在广东地区的９８次地闪中有连续电流的地闪占５２％,连续电流的平均持续时间为１５８．２ｍｓ。在这两个地区,带有连续电流最多的是有２次或３次回击的地闪,连续电流的持续时间与产生它的回击和前一回击之间的时间间隔△Ｔ呈     

北京强雷暴的地闪活动与雷达回波和降水的关系

对2000-2001年发生在北京地区的8次天气过程进行了闪电与降水特征的统计分析，并针对两类典型暴雨和冰雹天气进行了详细的雷达、闪电特征分析。结果表明：降雨和降雹天气的地闪特性具有明显差异。降雹天气的正闪比例较大，特别在降雹前正闪频数增加剧烈。闪电通常发生在45dBZ以上的回波区，比目前“闪电在中纬度通常发生在30～45dBZ”等其他一些研究结果偏高。     

Electrification of volcanic plumes

Volcanic lightning, perhaps the most spectacular consequence of the electrification of volcanic plumes, has been implicated in the origin of life on Earth, and may also exist in other planetary atmospheres. Recent years have seen volcanic lightning detection used as part of a portfolio of developing techniques to monitor volcanic eruptions. Remote sensing measurement techniques have been used to monitor volcanic lightning, but surface observations of the atmospheric electric Potential Gradient (PG) and the charge carried on volcanic ash also show that many volcanic plumes, whilst not sufficiently electrified to produce lightning, have detectable electrification exceeding that of their surrounding environment. Electrification has only been observed associated with ash-rich explosive plumes, but there is little evidence that the composition of the ash is critical to its occurrence. Different conceptual theories for charge generation and separation in volcanic plumes have been developed to explain the disparate observations obtained, but the ash fragmentation mechanism appears to be a key parameter. It is unclear which mechanisms or combinations of electrification mechanisms dominate in different circumstances. Electrostatic forces play an important role in modulating the dry fall-out of ash from a volcanic plume. Beyond the local electrification of plumes, the higher stratospheric particle concentrations following a large explosive eruption may affect the global atmospheric electrical circuit. It is possible that this might present another, if minor, way by which large volcanic eruptions affect global climate. The direct hazard of volcanic lightning to communities is generally low compared to other aspects of volcanic activity.     

Atmospheric Electrification in the Solar System

Atmospheric electrification is not a purely terrestrial phenomenon: all Solar System planetary atmospheres become slightly electrified by cosmic ray ionisation. There is evidence for lightning on Jupiter, Saturn, Uranus and Neptune, and it is possible on Mars, Venus and Titan. Controversy surrounds the role of atmospheric electricity in physical climate processes on Earth; here, a comparative approach is employed to review the role of electrification in the atmospheres of other planets and their moons. This paper reviews the theory, and, where available, measurements, of planetary atmospheric electricity which is taken to include ion production and ion–aerosol interactions. The conditions necessary for a planetary atmospheric electric circuit similar to Earth’s, and the likelihood of meeting these conditions in other planetary atmospheres, are briefly discussed. Atmospheric electrification could be important throughout the solar system, particularly at the outer planets which receive little solar radiation, increasing the relative significance of electrical forces. Nucleation onto atmospheric ions has been predicted to affect the evolution and lifetime of haze layers on Titan, Neptune and Triton. Atmospheric electrical processes on Titan, before the arrival of the Huygens probe, are summarised. For planets closer to Earth, heating from solar radiation dominates atmospheric circulations. However, Mars may have a global circuit analogous to the terrestrial model, but based on electrical discharges from dust storms. There is an increasing need for direct measurements of planetary atmospheric electrification, in particular on Mars, to assess the risk for future unmanned and manned missions. Theoretical understanding could be increased by cross-disciplinary work to modify and update models and parameterisations initially developed for a specific atmosphere, to make them more broadly applicable to other planetary atmospheres.     

Some observations of bipolar flashes during summer thunderstorms near Warsaw

Lightning discharges monitored by the SAFIR network system in Poland have been additionally identified over the 100×100 km area near Warsaw by single-point independent recordings of electric field and Maxwell current rapid changes. The data collected in summer thunderstorm days of 2002 showed some untypical properties of the lightning discharges which are rarely observed. Especially remarkable was a number of ground multi-stroke flashes with the return strokes (RS) which transported to the earth charges of opposite signs. Bipolar flashes (BF) of this kind were mostly involved in the events in which the nearby intracloud (ic) and cloud-to-ground (c-g) discharges were very closely associated in time. Events of such a close collocation of two different types of lightning discharges, previously called the complex lightning discharge events (CLDE), were quite often observed during summer thunderstorms in Poland. The events of this kind, i.e. 8 flashes, identified by the SAFIR detection system as BF’s present the multiple stroke flashes of the mean horizontal separation distance between striking points of particular RS equal to (2.8 ± 2.1) km and of the mean time interval between strokes of (46.8 ± 74.4) ms. The time separation between the observed BF and the adjacent ic flashes was from 0.1 to 335 ms, and horizontal separation distance between them ranged from 1.8 to 14.5 km. The multiplicity of the recorded BF’s ranged from 2 to 4 strokes. Four of these BF’s followed the ic discharge, but the other three preceded the ic and one was alone with no close ic.     

洛阳地区雷暴活动规律和雷灾分析

利用洛阳市及9县10个观测站1966-2005年的雷暴观测资料,统计分析了洛阳地区雷暴活动时空分布特征,结果显示:洛阳地区雷暴时空分布很不均匀,栾川、嵩县、孟津偏多,宜阳、新安、汝阳偏少,南北多中部少;20世纪60年代中期到70年代雷暴日数偏多,80年代至今雷暴日数偏少,但从80年代开始,洛阳地区雷暴日数有缓慢上升的趋势,年际变化幅度大,季节性特点非常明显,集中出现在4-9月,而夏季雷暴日数接近全年的80%。洛阳地区雷击人员伤亡事件主要发生在农村,造成的财产损失主要在市区,近年来雷击次数及所造成的损失呈上升趋势。     

新疆包古图斑岩铜矿伴生元素金和银赋存状态初步研究

新疆西准噶尔包古图斑岩铜矿床Au平均含量0.25g/t,Ag为2.56g/t,Cu为0.30%,属于富金斑岩铜矿。伴生金和银矿化作用有两期:早期为斑岩矿化,形成了Cu-Mo-Au矿化组合,是主矿化期;后期叠加了Cu-Au-Ag-Te-Bi矿化,规模不大,出露于矿床的局部部位,但对矿石起到了加富作用。通过对钻孔薄片和光薄片的镜下观察及电子探针成分分析,认为早期矿化中Au和Ag主要呈固溶体形式存在于硫化物中,分布比较均匀,基本上不出现独立矿物,Au含量明显高于Ag;晚期矿化形成了复杂的Cu-Au-Ag-Te-Bi矿物,矿石呈浸染状和脉状叠加在早期矿化之上,以银矿物为主,与多种碲铋类矿物共生,主要银矿物有碲银矿、铋-碲银矿(?)、银-辉碲铋矿(?)、银-硫铋铜矿、银金矿等。晚期矿化规模不大,但对于提高矿床的经济价值具有重要意义。