Blue optical observations of narrow bipolar events by ASIM suggest corona streamer activity in thunderstorms

This work was supported by the Spanish Ministry of Science and Innovation, Ministerio de Ciencia e Innovaci?n (AEI) under projects ESP2017-86263-C4-4-R and PID2019-109269RB-C43 and the FEDER program. S.?S. acknowledges a PhD research contract through the project ESP2017-86263-C4-4-R. F.?J.?P.?I., A.?L., D.?L., and A.?M. were supported by the European Research Council (ERC) under the European Union H2020 programme/ERC Grant Agreement 681257. Authors S.?S., F.?J.?P.?I., F.?J.?G.?V., A.?M., and A.?L. acknowledge financial support from the State Agency for Research of the Spanish MCIU through the ?Center of Excellence Severo Ochoa? award for the Instituto de Astrof?sica de Andaluc?a (SEV-2017-0709). ASIM is a mission of The European Space Agency (ESA). The project is funded by ESA and by national grants of Denmark, Norway, and Spain. We acknowledge VAISALA for the granted access to the GLD360 global lightning data set of great value for this work. The authors would like to thank Jiang Lingfeng of the National Satellite Meteorological Center, China Meteorological Administration, who helped preprocess related CTH data based on the data sharing proxy in Fengyun Satellite data center at https://bit.ly/2ZxNYUT. The authors would like to thank Mohd Riduan Ahamd of the Atmospheric and Lightning Research Lab, Centre for Telecommunication Research and Innovation (CeTRI), Fakulti Kejuruteraan Elektronik dan Kejuruteraan Komputer, Universiti Teknikal Malaysia Melaka, Hang Tuah 7 Jaya, 76100 Durian Tunggal, Melaka, Malaysia. FJPI acknowledges the sponsorship provided by the Federal Ministry for Education and Research of Germany through the Alexander von Humboldt Foundation.