Global warming will double the frequency of heavy rainfall in the tropics

Global warming will double the frequency of heavy rainfall in the tropics
Global warming will double the frequency of heavy rainfall in the tropics
Anonim

Climatologists have found that due to global warming, torrential rains in the tropics can be doubled. Because of this, more floods may occur, scientists write in the scientific journal Communications Earth & Environment.

“All climate models studied show that global warming will increase the random fluctuations in rainfall in the tropics. Interestingly, fluctuations in ocean surface temperatures will not change so much. This suggests that the nature of the relationship between ocean surface temperatures will change. and extreme precipitation, said Yoon Kensuk, a researcher at Busan National University (Republic of Korea) and one of the authors of the work.

In recent years, there have been many more floods, droughts and heat waves, as well as hurricanes and typhoons in the Atlantic and Pacific Ocean. Scientists speculate that this is due to global warming. However, the exact mechanisms of its effect on the weather are not yet fully known.

In particular, some scientists believe that hurricanes have become more frequent due to the fact that the increase in the concentration of CO2 in the atmosphere and the associated increase in average annual temperatures disrupted the circulation of heat and energy in the atmosphere. Their "surplus" is dumped in the form of powerful hurricanes and rains.

In the new work, Yoon Kensuk and her colleagues have discovered new manifestations of this phenomenon. They calculated changes in rainfall patterns in the Pacific region using two dozen recently developed climate models.

Typical rainfall in the tropics and equatorial latitudes off the Pacific coast is constantly changing due to El Niño and La Niña. The first phenomenon is associated with a sharp warming of the upper water layer in the central and eastern regions of the Pacific Ocean, and the second - with their cooling.

La Niña and El Niño replace each other every few years. Because of this, the circulation of ocean currents and winds in the atmosphere is restructured to a large extent. Because of this, droughts occur in some regions of the Earth, and heavy rains in others. Therefore, climatologists have long been trying to predict how global warming will affect both of these phenomena.

The calculations of the authors of the article show that global warming will dramatically increase the differences between La Niña and El Niño. As a result, over the next 80 years, El Niño-related torrential rains in the tropics will be almost doubled. Because of this, floods and river overflows can occur more often.

Scientists also found that this will not be due to an increase in the difference in ocean surface temperatures during El Niño and La Niña, but with how it affects the circulation of steam and energy in the Earth's atmosphere. According to the researchers, the new climate regime in the tropics and the nature of its influence on precipitation should be taken into account when predicting the climate and living conditions in those countries that are strongly influenced by El Niño and La Niña.

“The warmer the atmosphere, the more vapor it can absorb. This directly affects the amount of precipitation and the intensity of rainfall. In addition, the rise in temperatures at the equator will accelerate the rise of air masses into the upper atmosphere, which will pull humid air masses from the tropics. will increase precipitation when the conditions are right, summed up Li Chongli, a professor at Busan National University and another author of the study.

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