The Global Lightning Dataset GLD360 network detects between 1 and 3 million lightning events around the world every day of the year. Lightning activity is not uniformly distributed across the globe. About ten times as many flashes occur over land than over the oceans, and the majority of global lightning is concentrated in the tropics. Over the course of a year, highest flash rate regions follow the inclination of the sun. The northern hemisphere sees more activity during June through August; the southern hemisphere has higher flash rates in January through March. These seasonal patterns can be clearly seen in these images, which show the total number of events detected in each month per square kilometer. The color scale ranges from less than .01 lightning pulses per square kilometer in the corresponding month to over 20 pulses per square kilometer. Each color range corresponds to a factor of two of increase in the number of events. This dataset runs from June 2011 through August 2012.
Global lightning detection is monitored as lightning discharges generate broadband radio pulses that contain a peak component in the Very Low Frequency (VLF; 3-30 kHz) range, which are reflected off of the ground and the conductive region of the upper atmosphere called the ionosphere. GLD360 is a global, real-time long range lightning detection and location network that measures these VLF radio pulses at multiple sensors placed in strategic locations around the globe. The GLD360 network is maintained by Vaisala