Study of cloud-to-ground lightning and precipitation and their seasonal and geographical characteristics over Taiwan Y.-A. Liou, S.K.Kar ⁎ Center for Space and Remote Sensing Research, National Central University, Chung-Li,Taiwan a r t i c l e i n f o a b s t r a c t Article history: Received 20 April 2009 Received in revised form 3 August 2009 Accepted 21 August 2009 A long term (1998–2006) study of annual precipitation and cloud-to-ground (CG) lightning has been made at 31 stations over Taiwan. The CG-lightning data were collected by the ground- based Lightning Location System (LLS) builtby Tai-Power Company ofTaiwan while the precipitation data were collected from the Central Weather Bureau (CWB) of Taiwan. For the present study, a spatial scale of 0.1° latitude × 0.1° longitude (≈10 2 km 2 ) is selected to determine the flash density. CG-lightning and precipitation data are used to compute the values of “rain yield”, defined as the mass of rain produced per CG-lightning flash in units of kg fl −1 over a given surface area. The rain yield is found to vary considerably with seasonal and climatic conditions,and geographicallocation. A positive linear correlation is observed between precipitation and lightning flash density with a highest correlation coefficient of 0.70 over inland stations. Out of the 31 stations, 13 stations are inland stations and these stations show higher rain yields clustering close to a mean of 0.7 × 10 10 kg fl −1 , compared to the coastal stations which show a mean value 1.4 × 10 10 kg fl −1 . When the stations are classified according to seasonal climate zones, the winter and winter-dominant rainfall stations show comparatively highervalue of rain yield with an average of 2.8 × 10 10 kg fl −1 than the summer and summer-dominant rainfall stations which exhibit a significantly lower value of rain yield of 2.1 × 10 10 kg fl −1 . Inland stations exhibit a lower value of rain yield with a mean of 1.6 × 10 9 kg fl −1 and 1.4 × 10 10 kg fl −1 respectively during warm and cold seasons compared to the coastal stations. For each station, the average cold season rain yields are signi ficantly highe than that of warm season values. These differences in rain yield values are attributed to local surface heating which indirectly controls such parameters as cloud base height and convectively available potential energy (CAPE) in the atmosphere. The variation of rain yield with geographical, seasonal,and climatic conditions, found in our observations, are in good agreement with studies found in the literature from other parts of the world. © 2009 Elsevier B.V. All rights reserved. Keywords: Cloud-to-ground lightning Precipitation Rain yield 1. Introduction Close association between precipitation and lightning has been investigated since time immemorial. Before the use of lightning detection networks,sporadic research was con- ducted to study lightning and other associated meteorological events ( Battan,1965; Piepgrass et al., 1982). Battan (1965) computed visually the CG-lightning flashes and found the number of counts to be wellcorrelated to the precipitation estimation from nearby thunderstorms. Later, with the deployment of lightning detection networks, many more sophisticated studies have been performed, especially in the United States. Because of a simple structure, nearly uniform spatial coverage and continuous observation, lightning loca- tion data has become advantageous for its use. Important applications of lightning and precipitation have been possible because of the extensive coverage oflightning detection network by the use of lightning data. Radar estimated rainfall has been found to be positively correlated to the intensity of lightning (Reap and MacGorman, 1989; Williams et al., 1992; Cheze and Sauvageot, 1997). Moore et al. (1962), Piepgrass et al. (1982), Jayaratne et al. (1995) and Jayaratne and Kuleshov (2006) have shown the intense falls of precipitation Atmospheric Research 95 (2010) 115–122 ⁎ Corresponding author. Tel.: +886 3 4227151; fax: +886 3 4254908. E-mail address: sanjib_kar@hotmail.com (S.K. Kar). 0169-8095/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.atmosres.2009.08.016 Contents lists available at ScienceDirect Atmospheric Research j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / a t m o s