Himalayan katabatic winds a glacial guardian amid climate change

The mighty Himalayas in Nepal. File Picture: Rob Smith / Summits with a Purpose Facebook Page

The mighty Himalayas in Nepal. File Picture: Rob Smith / Summits with a Purpose Facebook Page

Published Jan 19, 2024


Despite countless calls for more attention to the climate, global temperatures are still rapidly rising, which are warming oceans and melting glaciers. Scientists have long explained that mountaintops are often affected by the warming climate faster than other regions.

Glaciers, in particular, are a source of water for many areas, and melting can lead to higher sea levels and coastal flooding. Despite the increasing temperatures, scientists discovered an interesting phenomenon occurring in the Himalayas that keeps the glaciers colder than similar locations worldwide.

The world's tallest mountain range has its own defence mechanism against a warming climate, according to a study published in Nature Geoscience. Essentially, the warming climate increases the temperature gap between the air above the Himalayan glaciers and the cooler air directly in contact with the ice surface, one CNN report explained, adding that, "as the cool, dry surface air gets cooler and denser, it sinks. The air mass flows down the slopes into the valleys, causing a cooling effect in the glaciers' lower areas and neighbouring ecosystems".

The downhill winds produced are called katabatic winds. They do an efficient job controlling the maximum temperatures on the surface of the glaciers, which occur during the summer.

"While the minimum temperatures have been steadily on the rise, the surface temperature maxima in summer were consistently dropping," Franco Salerno, co-author of the report and researcher for the National Research Council of Italy, said in a press release.

This type of wind creates two conflicting outcomes: decreasing daytime temperatures which "has the tendency to reduce the melting of glaciers," and increased precipitation at lower elevations but decreased precipitation at higher elevations near the glaciers, which "has caused them to lose mass over the past few decades".

The researchers suggest that katabatic winds are not exclusive to the Himalayas and can occur anywhere the conditions are met and while the phenomenon can help to slow the melting of some glaciers, it isn't enough to stop glacial melting.

Thomas Shaw, who worked on the study, told CNN: "The cooling is local, but perhaps still not sufficient to overcome the larger impact of climatic warming and fully preserve the glaciers."

Himalayan glaciers melted 65% faster in the 2010s than in the previous decade, and the risk is growing, with research showing that the Himalayan mountain range could lose 80% of its glaciers by 2100. Efforts to curb warming need to happen in order to save the glaciers.

"We believe that the katabatic winds are the response of healthy glaciers to rising global temperatures and that this phenomenon could help preserve the permafrost and surrounding vegetation," said Nicolas Guyennon, one of the study's authors, in the press release.

He added that "glaciers are indeed essential in maintaining the water security in their ecosystems. But how long can healthy glaciers fight back?" As of now, Himalayan glaciers appear to be doing slightly better than other glaciers worldwide.

Francesca Pellicciotti, lead author of the study, concluded, "Even if the glaciers can't preserve themselves forever, they might still preserve the environment around them for some time," and that there needs to be "more multidisciplinary-research approaches to converge efforts toward explaining the effects of global warming".

IOL Environment