Lightning meteorology focuses on investigating the lightning activities in different types of convective weather systems and the relationship of lightning to the dynamic and microphysical processes in thunderstorms.With the development and application of advanced lightning detection and location technologies,lightning meteorology has been developed into an important interdiscipline between atmospheric electricity and meteorology.This paper mainly reviews the advances of lightning meteorology research in recent years in China from the following five aspects:1) development of advanced lightning location technology,2) characteristics of lightning activity in different convective systems,3) relationship of lightning to the dynamic and microphysical processes in thunderstorms,4) charge structure of thunderstorms,and 5) lightning data assimilation techniques and application to severe weather forecasting.In addition,some important aspects on future research of the lightning meteorology are proposed.
Data from the Beijing SAFIR 3000 lightning detection system and Doppler radar provided some insights into the three-dimensional lightning structure and evolution of a leading-line and trailing-stratiform (LLTS) mesoscale convective system (MCS) over Beijing on 31 July 2007. Most of the lightning in the LLTS-MCS was intracloud (IC) lightning, while the mean ratio of positive cloud-to-ground (+CG) lightning to -CG lightning was 1:4, which was higher than the average value from previous studies. The majority of CG lightning occurred in the convective region of the radar echo, particularly at the leading edge of the front. Little IC lightning and little +CG lightning occurred in the stratiform region. The distribution of the CG lightning indicated that the storm had a tilted dipole structure given the wind shear or the tripole charge structure. During the storm's development, most of the IC lightning occurred at an altitude of ～9.5 km; the lightning rate reached its maximum at 10.5 km, the altitude of IC lightning in the mature stage of the storm. When the thunderstorm began to dissipate, the altitude of the IC lightning decreased gradually. The spatial distribution of lightning was well correlated with the rainfall on the ground, although the peak value of rainfall appeared 75 min later than the peak lightning rate.
Electrification and simple discharge schemes are coupled into a 3D Regional Atmospheric Model System(RAMS) as microphysical parameterizations, in accordance with electrical experiment results. The dynamics, microphysics, and electrification components are fully integrated into the RAMS model, and the inductive and non-inductive electrification mechanisms are considered in the charging process. The results indicate that the thunderstorm mainly had a normal tripole charge structure.The simulated charge structure and lightning frequency are basically consistent with observations of the lightning radiation source distribution. The non-inductive charging mechanism contributed to the electrification during the whole lifetime of the thunderstorm, while the inductive electrification mechanism played a significant role in the development period and the mature stage when the electric field reached a large value. The charge structure in the convective region and the rearward region are analyzed, showing that the charge density in the convective region was double that in the rearward region.
Data from the World Wide Lightning Location Network(WWLLN) were used to analyze the lightning activity and the relationship between maximum sustained wind and lightning rate in 69 tropical cyclones over the Northwest Pacific Ocean from 2005 to 2009. The minimum lightning density was observed in the category 2 typhoon Kong-Rey(2007), with a value of only 1.15 d-1(100 km)-2. The maximum lightning density occurred in the category 2 typhoon Mitag(2007), with a value of 510.42 d-1(100 km)-2. The average lightning density decreased with radius from the typhoon center in both weak(categories 1–3) and super(categories 4–5) typhoons. The average lightning density in the inner core of super typhoons was more than twice as large as that for weak typhoons. Both groups of typhoons showed a near-monotonic decrease in lightning density with radius. Results also showed that lightning activity was more active in typhoons that made landfall than in those that did not. The mean correlation coefficient between the accumulated flashes within a 600-km radius and the maximum wind speed in the weak typhoons and super typhoons was 0.81 and 0.74, respectively. For more than 78%(56%) of the super(weak) typhoons, the lightning activity peaked before the maximum sustained wind speed, with the most common leading time being 30(60) h. The results suggest that, for the Northwest Pacific Ocean, lightning activity might be used as a measurement of the intensification of typhoons.
Data from the World Wide Lightning Location Network (WWLLN) for the period 2005-2011 and data composite of the Lightning Imaging Sensor/Optical Transient Detector (LIS/OTD) for 1995-2010 are used to analyze the lightning activity and its diurnal variation over land and ocean of the globe. The Congo basin shows a peak mean annual flash density of 160.7 fl km-2 yr-1 according to the LIS/OTD. The annual mean land to ocean flash ratio is 9.6:1, which confirms the result from Christian et al. in 2003 based on only 5-yr OTD data. The lightning density detected by the WWLLN is in general one order of magnitude lower than that of the LIS/OTD. The diurnal cycle of the lightning activity over land shows a single peak, with the maximum activity occurring around 1400-1900 LT (Local Time) and a minimum in the morning from both datasets. The oceanic diurnal variation has two peaks: the early morning peak between 0100 and 0300 LT and the afternoon peak with a stronger intensity between 1100 and 1400 LT over the Pacific Ocean, as revealed from the WWLLN dataset; whereas the diurnal variation over ocean in the LIS/OTD dataset shows a large fluctuation.
