Surprising natural phenomenon that helps preserve glaciers, reduces the effects of global warming - observation in the Himalayas

Recently CNN.co.jp reported the following:

氷河の保全助ける驚きの自然現象、温暖化の影響抑える効果　ヒマラヤで観測

2023.12.13 Wed posted at 15:01 JST

（ＣＮＮ） 世界最高峰が連なるヒマラヤ山脈の氷河は急速に融解が進んでいる。しかし、気候変動の影響を抑えて氷河の保全を助ける驚きの自然現象が起きていたという研究結果がこのほど発表された。

４日の科学誌ネイチャー・ジオサイエンスに発表された論文によれば、温暖化が進んで一定の標高の氷河に到達すると、冷たい強風が斜面を吹き降りる驚きの現象が観測された。

論文を発表したオーストリア科学技術研究所（ＩＳＴＡ）の研究者によれば、ヒマラヤ山脈で気温が上昇すると、氷河の上空にある大気と氷河に接する表層部の大気との温度差が大きくなる。それによって氷河の表面で乱流熱交換が増え、表面の大気の冷却効果が強まる。

冷たく乾燥した表面大気は、温度が下がって密度が濃くなると下降する。この大気が斜面を下って峡谷に流れ込み、低い場所にある氷河や周辺の生態系の冷却効果をもたらす。

ヒマラヤ山脈の氷雪は１２の河川に流れ込み、１６カ国で約２０億人の水供給源となっている。この地域は今後何十年にもわたって気温の上昇が予想されることから、ヒマラヤ山脈の氷河が自らを保全するこの冷却効果が持続するかどうかを見極める必要がある。

今年６月の報告によると、２０１０年代にヒマラヤ山脈の氷河が融解したペースは、その前の１０年に比べて６５％加速していた。

ＩＳＴＡの研究者によると、今回ヒマラヤ山脈で観測された氷河の冷却現象は、条件が整えば世界各地の氷河で発生している可能性もある。ただ、「もっと大きな気候変動の影響を克服して氷河を完全に保つためには、それでも不十分かもしれない」と別の研究者は指摘している。

Translation

(CNN) Glaciers in the Himalayas, home to the world's highest peaks, were melting rapidly. However, research had recently revealed a surprising natural phenomenon that was occurring which helped reduce the effects of climate change and preserve glaciers.

According to a paper published in the scientific journal Nature Geoscience on the 4th, a surprising phenomenon has been observed where, as global warming progressed and reached a glacier at a certain altitude, cold, strong winds blow down the slope.

According to researchers at the Austrian Institute of Science and Technology (ISTA), who published the paper, as temperatures rose in the Himalayas, the difference in temperature between the atmosphere above the glaciers and the surface layer in contact with the glaciers increased. This would increase turbulent heat exchange at the glacier's surface, increasing the cooling effect of the surface atmosphere.

The cold, dry surface atmosphere descended as the temperature dropped and the density became denser. This air flowed down the slopes and into the canyons, cooling lower-lying glaciers and surrounding ecosystems.

Ice and snow from the Himalayas flowed into 12 rivers, providing water for approximately 2 billion people in 16 countries. With temperatures expected to rise in the region for decades to come, it was necessary to determine whether the cooling effect of self-preserving Himalayan glaciers could persist.

A report in June found that in the 2010s Himalayan glaciers were melting 65% faster than in the previous decade.

According to ISTA researchers, the glacier cooling phenomenon observed in the Himalayas could occur on glaciers around the world if conditions were right. But another researcher said "that may not be enough to overcome the effects of larger climate change in order to keep the glaciers intact".

So, a research has revealed that a surprising natural phenomenon is occurring in the Himalayas that help reduce the effects of climate change and preserve glaciers. Researchers believe that the glacier cooling phenomenon observed in the Himalayas could occur on glaciers around the world if conditions are right. It is an interesting scientific finding.