Significant changes in sea surface temperature are partly responsible for the constant droughts observed in North America and the Mediterranean in recent decades, according to new studies.
Researchers analyzed the data obtained from 1957 to 2002 and found that the sea surface temperature in the North Pacific and North Atlantic is becoming increasingly volatile, and extreme values persist longer.
Ocean temperature is the main factor determining the conditions on land, and the researchers showed that the observed changes are related to increasingly variable temperatures on land and the growth of extreme temperatures.
Researchers from the universities of Exeter, Montpellier and Wageningen related this phenomenon to droughts in North America and the territories around the Mediterranean.
“Our data indicate that the North Atlantic and North Pacific regions experienced more significant and longer-term sea surface temperature changes, which contributed to extreme and persistent temperature anomalies on some parts of the planet’s surface,” said Professor Tim Lenton of the University of Exeter.
Researchers who systematically analyze monthly data on the temperature of water to search for regularities note that such long periods of high or low temperatures can have the effect of “something more than a simple summation of individual components.”
“For example, prolonged intense heat can have a greater impact on the death rate of people than the sum of these indicators on some hot days, and a long-term drought can lead to more severe economic consequences in agriculture than the sum of individual dry periods,” said Professor Lenton .
The study is published in the journal Scientific Reports.