NASA's satellite observations have revealed that lightning occurs both over the ocean and the land, but happens more often in the latter in areas that are proximal to the equator.
The collected data were used to come up with a map, counting the average yearly lightning flashes per square kilometer in a span of 28 years- 1995 thru 2013, the NASA Earth Observatory wrote. The map showed areas that are not frequented by lightning strikes and colored them purple and gray, while areas that experiences lightning the most are pink-colored.
The map utilized the data collected through the LIS (Lightning Imaging Sensor) under the Tropical Rainfall Measuring Mission satellite from 1998 to 2013 and the OTD (Optical Transient Detector) under the OrbView-1/Microlab satellite from 1995 to 2000.
Researchers revealed that lightning occurs more over the land because Earth naturally absorbs sunlight. This causes more intensified heating level than what occurs over the bodies of water. The particular phenomenon has led to higher atmospheric instability and stronger convection; hence, lightning storms.
Regional trends were also presented. In Brahmaputra Valley, India, lightning only strikes during May, right before a monsoon primarily characterized by tremendously fewer lightning occurrences. Northwestern South America and Central Africa, on the other hand, experience year-round lightning, while the highest lightning concentration is observed in the Northwestern Venezuela, specifically in the Lake Maracaibo and the Democratic Republic of Congo.
Daniel Cecil, Climate Center and Global Hydrology member, said "The satellite's longer observation records have allowed the team to more accurately and confidently identify a few of these finer information and details. We are now equipped to examine seasonality and the variability of lightning daily and yearly."
All findings are published in the Atmospheric Research journal.