The South American lightning puzzle and the South Atlantic Anomaly

Abstract

The extensive information on global lightning activity gathered by the space-based Optical Transient Detector (OTD) and Lightning Imaging Sensor (LIS) finds endless applications in many research areas. When these satellites pass the South Atlantic Anomaly (SAA) centered near the lower east coast of South America, precipitating cosmic particles cause numerous false lightning detections. This induces an application of increasingly aggressive filtering, resulting in higher rejection rates of true flashes along with the radiation noise. Differences in the exposure to SAA and filtering procedures result in notable differences between OTD and LIS lightning distributions in this region. We draw readers' attention to these differences, and show that such filtering procedures may result in a systematic loss of information important for Schumann resonance and Transient Luminous Events. We also suggest that the high lightning activity in the SAA region indicated by LIS, may be a manifestation of a link between the cosmic and Earth weather, and possibly a yet unexplored feedback mechanism between lightning discharges and the cosmic particle precipitation.