Description

The next generation geostationary satellite system starting with GOES-R will include a geostationary lightning mapper (GLM). The GLM will provide nearly continuous times and locations of total lightning with an accuracy of about 10 km over most of the field of view of GOES-east and west. Previous studies with ground-based lightning networks have revealed a number of interesting relationships between storm structure and the lightning distribution. Using data from the National Lightning Detection Network (NLDN) Molinari et al. (1999) have shown that the lightning density (strikes per unit area and time) tends to have a bi-modal structure as a function of radius from the storm center, with maxima near the eyewall region and in the rainband region (150-300 km radius) and a minimum in between. Their study and more recent analysis with the Long-range Lighting Detection Network (LLDN) (Squires and Businger 2008) indicate that the lightning near the storm center tends to be much more transient than that in the rainband region. Corbosiero and Molinari (2002) showed a strong relationship between the environmental shear and the azimuthal distribution of lightning, with a maximum in strikes on the down shear side of the storm.

In this study the relationship between lighting density and intensity changes will be investigated for a large sample of Atlantic and East Pacific tropical cyclone cases using data from the World Wide Lightning Location Network (WWLLN). To help isolate the influences of vertical shear, the dataset is stratified into low- and high-shear regimes, where the shear is calculated from the NCEP global forecasting system (GFS) analysis fields. The WWLLN data is also being compared with GOES imagery to aid in the interpretation. This web page shows some case studies of interest.