Introduction

There are two primary reasons for considering winter lightning in Japan in a separate chapter of this book. First, lightning discharges produced by winter storms in the coastal area of the Sea of Japan exhibit a number of features, discussed in Section 8.4, that have not been observed in the summer season in Japan or in any season in other geographical locations. It is these discharges in the Japan Sea coastal area (see Figs. 8.1a and b) that are usually referred to as winter lightning in Japan, although winter lightning in other regions of Japan may not have similar characteristics. Second, a considerable amount of data on winter lightning in Japan has been published over the last two to three decades. These data are scattered over many papers in different journals and, therefore, are in need of a consolidating review.

It is possible and even likely that the conditions conducive to the production of lightning discharges similar to those observed in winter storms in Japan exist in other seasons and/or locations. If so, further lightning research may lead to the replacement of the term “winter lightning in Japan” by another term that provides more insight into the nature of this phenomenon.