Lightning over Tibetan Plateau and its relation with winds associated with CAPE

Association of lightning with winds over Tibetan Plateau (TP) is examined by analyzing lightning data during the period 1999–2013. The study reveals that nearly 92% lightning activity occurred during April to September is associated with the wind circulation, especially cyclonic circulation. Nearly 58% of lightning is found to happen during May (18.6%), June (19.29%), and July (19.56%). Less vertical wind shear (less than 10 m/s) and high CAPE (more than 400 J/kg) are found to be associated with lightning. Analysis shows that negative correlation exists between wind shear and lightning. Results reveal that high wind shear tends to restrict the growth of convection, resulting in lightning. On annual scale, there exist negative correlation between lightning and wind shear and insignificant correlation between lightning and CAPE for April-September. However, a new relationship is established when CAPE and shear are taken together, and a strong positive correlation is found between lightning and CAPE per shear (CAPE/shear). Hence, we propose that for better understanding on lightning over Tibetan Plateau, it would be much more useful to consider CAPE/shear rather than CAPE or wind shear alone.