Lightning observations at Tokyo Skytree

Observation of lightning hitting Tokyo Skytree, a 634-m high freestanding broadcasting tower, started in February 2012. In 2012 and 2013, current waveforms associated with 24 lightning flashes have been obtained by specially designed wide-band Rogowski coils installed at a height of 497m. The ratio of upward lightning is quite different in 2012 and 2013. In addition to these, we have observed development of upward connecting leaders started from the top of Tokyo Skytree with a high-speed camera.