News Excerpt: 

A surprising phenomenon has emerged in the mighty Himalayas that might slow down the effects of the global climate crisis.

About the phenomenon:

This study was published using data from the Pyramid International Laboratory/Observatory climate station on Mount Everest, the world’s tallest summit.

• There is a phenomenon of cooling of the Himalayas taking place despite the global warming crisis noted by scientists.
• Scientists have noted that when high temperatures hit high-altitude ice masses, ‘katabatic’ winds are triggered that blow cold air to lower-altitude areas.
• However, studying the impact of this phenomenon becomes vital and significant as the Himalayan mountain range feeds into 12 rivers that provide fresh water to nearly 2 billion people in 16 countries.
• While this phenomenon may slow down the effects of global warming in some areas, its sustainability is not guaranteed over the coming decades.
• Concerns: 
• Scientists noted that this phenomenon doesn’t stop the melting of the glaciers due to climate change.
• The glaciers in the Himalayas melted 65 percent faster in the 2010s compared with the previous decade.
• The main impact of rising temperature on glaciers is an increase of ice losses, due to melt increase.
• The cooling phenomenon of the Himalayas is local, but perhaps still not sufficient to overcome the larger impact of climatic warming and fully preserve the glaciers.

About Katabatic winds:

• The cool air, of the high plateaus and ice fields draining into the valley is called katabatic wind.
• It occurs at night when the highlands radiate heat and are cooled.

• A temperature gap is created between the air flowing above the mountains and the cooler air directly in contact with ice masses.
• This leads to an increase in turbulent heat exchange at the glacier’s surface and stronger cooling of the surface air mass.
• As the warm air gets cooler and denser, it sinks, triggering the katabatic winds in neighbouring areas down the slope.
• When a katabatic wind is warmed by compression during its descent into denser air, it is called a foehn. A large-scale katabatic wind that descends too rapidly to warm up is called a fall wind.

Prelims PYQ:

Q. The seasonal reversal of winds is the typical characteristic of: (UPSC 2014)

(a) Equatorial climate

(b) Mediterranean climate

(c) Monsoon climate

(d) All of the above climates

Q. Consider the following statements:​  (UPSC 2021)

1. In the tropical zone, the western sections of the oceans are warmer than the eastern sections owing to the influence of trade winds.​
2. In the temperate zone, westerlies make the eastern sections of oceans warmer than the western sections.​

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2 

(d) Neither 1 nor 2