Why Do Thunderstorms Produces more in Cities More than Rural Areas?
According to the new study given by Northern Illinois University researchers, published in Journal of the Royal Meteorological Society, mostly those big cities which are located in hot and humid environments, spews more thunderstorms as compare to rural areas. The Journal also reported that the storm risk was greatest for urban and suburban Atlanta in the late afternoon and early evening during July and August.
The scientists have established that thunderstorm births were notably higher on weekdays compared with weekend days, because of increased pollution levels within the city which relates to industry and commuting. The city heat-island effect, in which dry, exposed surfaces such as roofs and pavement absorb more solar energy than less-developed areas with tree cover, farm fields or bodies of water, be a factor. This additional heat means low pressure which can form atop city areas, with higher pressure in countryside areas, sparking convection that can cause thunderstorms.
A co-author Walker Ashley, who is an NIU meteorology professor, said in the context of a study that, the study presents the first evidence that urban areas birth or initiate more thunderstorms than the surrounding rural areas on a climatological timescale.
As compared with countryside, a city might experience two to three additional thunderstorms per year. It is the first time than anyone has showed a difference between birthing of thunderstorms in rural versus urban areas.
By using the radar data, the researchers charted thunderstorm births over a 17 year period from 1997-2013, in an area of the southeastern United States included Atlanta. But the results almost certainly would be similar in cities with a similarly warm and humid climate. In a region like Chicago, where urban pollution’s effect on storms might be muted by winds from Lake Michigan, the effect might not be so pronounced. Throughout a 17-year period, the researchers marked the position of each thunderstorm born in northern Georgia and northeastern Alabama. There were almost 26,000 thunderstorms detected during the period 1997-2013.
An earlier study in 2012, by a team of researchers that included Northern Illinois meteorology professor Walker Ashley, found that large cities in the southeastern U.S. had a much higher danger of heavy rainfall during summertime thunderstorms than cities in another place.