Fig. 10
From: Spatial distribution of cold-season lightning frequency in the coastal areas of the Sea of Japan
Lightning frequency distributions and atmospheric conditions at the surface for case A. a Time series maps of lightning frequency distribution. The lightning frequency on the map is an hourly average calculated in a 3 h time window around the reference time. b Sea-level pressure (solid lines) and surface air temperature (broken lines) distributions obtained by MSM-GPV. Contour interval of sea-level pressure is 4 hPa. “L” represents the center of the cyclone defined as the point at which sea-level pressure is the lowest. Locations of cold/warm fronts are obtained from JMA’s surface weather charts