CHUVA lightning mapping field campaigns: First results and contributions to GOES-R and MTG

The CHUVA [Cloud processes of tHe main precipitation systems in Brazil: A contribUtion to cloud resolVing modeling and to the GPM (GlobAl Precipitation Measurement)] project objective is to characterize the main precipitating systems observed in Brazil in support of the Global Precipitation Measurement (GPM) mission. To achieve this objective, CHUVA is conducting several field campaigns in Brazil to measure the 3D precipitation structure (mobile XPOL, 2 vertical pointing radars – MRR 2, MP3000 radiometer), the electrical activity (field mills, lightning location systems and high-speed video cameras), and the meteorological conditions (radiosondes and weather stations). From November 2011 to March 2012, CHUVA took place in the metropolitan region of São Paulo and Vale do Paraiba, where the primary science objective was to combine measurements of total lightning activity, lightning channel mapping, and detailed information on the location of cloud charge regions of thunderstorms with the planned CHUVA observations of the physical processes of cloud development. This specific component of the field experiment included collaboration between Brazilian, US, and European government, university, and industry participants who deployed several lightning location systems (LLS) in support of the GOES-R Geostationary Lightning Mapper (GLM) and MTG Lightning Imager (LI) pre-launch activities. The LLS systems provided total lightning information coincident with overpasses of the Tropical Rainfall Measuring Mission (TRMM) Lightning Imaging Sensor (LIS) and the geostationary MSG SEVIRI (Spinning Enhanced Visible and Infrared Imager) that will be used to generate proxy data sets for GOES-R and MTG.

As a result of this collaborative field campaign, we acquired the most comprehensive performance assessment of almost all lightning networks available today. This assessment will help us understand the performance characteristics of various lightning locating systems, an essential task to enable and improve the proxy data and validation protocols for GLM and LI future datasets. Also, we were able to acquire detailed information about severe thunderstorms that produced hail, damaging winds and flooding over the metropolitan area of Sao Paulo City, Vale do Paraiba and across the state of Sao Paulo. Local convection and a few organized convective systems were responsible for pea to tennis ball size hail. Selected thunderstorm events are being used to generate multi-sensor and multi-platform data sets for developing nowcasting and severe weather detection algorithms.

With the success of this field experiment, we are extending the lightning mapping campaign to the next CHUVA field experiment, which will take place in the southern region of Brazil at Santa Maria, RS. This region produces the most electrically active mesoscale convective systems on Earth. For this campaign we will again have total lightning data, field mills and high-speed video cameras to augment the planned observations of the physical processes of cloud development.