From Drought to Torrential Rain... Why is Weather Swinging to Extremes?

[Anchor]

The torrential rain that hit Geoje was record-breaking in both volume and intensity. It was a torrential downpour of a scale that occurs only once every 200 years.

Until just recently, the southern regions were suffering from severe droughts. What is the cause behind this sudden shift to such extreme weather? Reporter Jeong Gu-hui has the details.

[Reporter]

Soil contains moisture that is not easily visible to the naked eye.

As this moisture evaporates, it takes away surrounding heat and plays a role in cooling the ground.

However, when a heatwave causes a drought, the soil moisture available to cool the heat decreases.

This reduces the cooling effect, and unless it rains, the heatwave intensifies again, creating a vicious cycle that further worsens the drought.

When the Korea Meteorological Administration analyzed 113 years of data from 1912 to 2024, the number of days with precipitation decreased by 0.68 days every 10 years, meaning a decrease of 6.8 days over 100 years.

Conversely, total annual precipitation during the same period increased by 178 mm per 100 years.

The fact that rainy days decreased while precipitation increased means that rain did not fall often, but when it did, it poured all at once, much like the recent downpours around Geoje and Tongyeong.

As temperatures rise, heavy rain becomes more frequent.

A volume of air measuring 1 meter in width, length, and height can hold up to 9.4 grams of water vapor at 10°C (50°F), and for every 10°C (18°F) increase in air temperature, the maximum water vapor capacity increases by about 70%.

Since even a 1-degree Celsius (1.8°F) rise in air temperature increases water vapor by 7%, the amount of rain dumped at one time increases correspondingly.

In other words, as temperatures rise due to global warming, the polarization between droughts and heavy downpours is becoming more severe.

Today (August 18), about 40 mm of rain fell in Geoje as well.

Currently, the North Pacific high-pressure system is positioned mainly around Japan, and water vapor continues to flow in along the edges of this high-pressure system.

As the North Pacific high-pressure system moves slightly northward, tomorrow, 5 to 30 mm of rain is expected in Honam, southern Chungcheong, and western Gyeongbuk.

In addition, some other southern regions will experience passing showers.

There are no forecasts for heavy rain for the time being, but under this atmospheric pressure pattern, heavy rain could fall at any time if a low-pressure system or cold air approaches.

Unlike during the extreme heatwaves when the dual high-pressure systems covering the Korean Peninsula blocked typhoons, if a typhoon develops this time, South Korea could be directly affected. Therefore, we must closely monitor the movement of the high-pressure system moving forward.

(Video Editing: Kim Ho-jin, Design: Seo Seung-hyun)
※ Please note: This article was translated by AI and may contain errors.