Blue Corona Discharges Detected by ASIM

Blue corona discharges, also known as Blue LUminous Events (BLUEs), are often observed at the top of thunderclouds. They are bursts of streamers, appear with strong blue emissions at 337 nm from the second positive system of N₂ in the near-ultraviolet band with weak or no red emissions in the atomic oxygen band of lightning leaders at 777.4 nm. Since April 2018, the Atmosphere-Space Interactions Monitor (ASIM) launched to the International Space Station (ISS), there is a growing number of studies of blue corona discharges based on ASIM measurements. Here, we summarize some recent results including 1) global distribution of the BLUEs; 2) the different types of the BLUEs; 3) correlation between BLUEs and Narrow Bipolar events (NBEs); 4) the cloud microphysics related to the BLUEs; 5) the initial results of the prediction of the BLUEs based on meteorological variables.