New study shows that drought, heat waves and cold spells are linked to air flow changes. The results of a new study by researchers at the University Of Exeter, Melbourne shows Variations in high-altitude wind patterns particularly in parts of Europe, Asia and US to different extreme weather conditions.
Changes in air flow patterns around the Northern Hemisphere are a major influence on prolonged bouts of unseasonal weather, whether it be hot, cold, wet or dry. The high altitude winds normally blow from west to east around the planet but do not follow a straight path. The flow meanders to the north and south in a wave like path.
These wave patterns are responsible for sucking either warm air from the tropics or cold air from the Arctic, Europe, Asia or US. They can also influence rainfall by steering rain-laden storms.
Dr James Screen, a Mathematics Research Fellow at the University of Exeter and lead author of the study said, “The impacts of large and slow moving atmospheric waves are different in different places. In some places amplified waves increase the chance of unusually hot conditions and in others the risk of cold, wet or dry conditions”.
The study showed that larger waves can lead to droughts in central North America, Europe and central Asia and western Asia exposed to prolonged wet spells. It also shows western North America and central Asia are more prone to heat waves while eastern North America is more likely to experience prolonged outbreaks of cold.
The study used detailed land based climate observations to identify episodes of abnormal temperature and rainfall from 1979-2012 and then examined the wave patterns during these events.
According to North Carolina State University, the circulation of wind in the atmosphere is driven by the rotation of the earth and the incoming energy from the sun. Wind circulates in each hemisphere in three distinct cells which help transport energy and heat from the equator to the poles. The winds are driven by the energy from the sun at the surface as warm air rises and colder air sinks.