Variability of lightning flash and thunderstorm over eastern China and Indonesia on ENSO time scales

The variability of lightning flashes and thunderstorms over eastern China and Indonesia on ENSO time scales was investigated during the period of 1998-2011 based on the flash data from OTD (Optical Transient Detector) and LIS (Lightning Imaging Sensor) and the precipitation data onboard the Tropical Rainfall Measuring Mission satellite (TRMM). It is found that a significant increase (decrease) of lightning activity appears over both of regions in spring and winter during ENSO warm (cold) episodes, which is similar to the previous studies, but an increase of lightning activity can be seen over both of regions in summer and autumn during ENSO cold episodes, and a decrease of lightning activity in summer appears over the northern part of east China during ENSO warm episodes. In spring and winter, lightning flashes generally increase with the intensification of ENSO warm episodes, which is more significant over east China than over Indonesia. During ENSO warm episodes, the decrease of thunderstorms over east China suggests that the increase of lightning flashes results from the increase of the intensity of thunderstorms, but the increase of thunderstorms over Indonesia implies that the increase of lightning flashes results from the increase of thunderstorm frequency. During ENSO cold episode, the number of thunderstorms decreases over both of regions, and the decrease of lightning flash over eastern China mainly results from the decrease of thunderstorm frequency, and the variation of lightning in Indonesia is affected by both of frequency and intensity of thunderstorms.