A ‘New Theory’ to Explain ‘Karakoram Anomaly’

19 Jul 2022

Indian Researchers have postulated a new theory towards solving the mystery of why few pockets of glaciers in the Karakoram Range are resisting glacial melt due to global warming called ‘Karakoram Anomaly’, defying the trend of glaciers losing mass across the globe, with the Himalayas being no exception.

They have attributed this phenomenon to recent revival of Western Disturbances (WDs).

What is ‘Karakoram Anomaly’?

Himalayan glaciers are fast receding under the impacts of global warming, and stifling stress on the water resources is inevitable in the coming decades. In contrast, the glaciers of central Karakoram have surprisingly remained unchanged or slightly increased in the last few decades. This phenomenon is called ‘Karakoram Anomaly’ – which has been puzzling glaciologists.
This is peculiar because the behaviour seems to be confined to a very small region, with only Kunlun ranges being another example of showing similar trends in the whole of Himalaya.

Recent Study/ New Theory

The study stresses the anomaly on the recent revival of western disturbance, which has been instrumental in triggering and sustaining the Karakoram Anomaly since the advent of the 21st century.
It is for the first time that a study brought forth the importance that enhanced WD-precipitation input during the accumulation period plays in modulating regional climatic anomaly.
WDs are the primary feeder of snowfall for the region during winters. The study suggests they constitute about around 65% of the total seasonal snowfall volume and about 53% of the total seasonal precipitation, easily making them the most important source of moisture.
The precipitation intensity of WDs impacting Karakoram has increased by around 10% in last two decades, which only enhances their role in sustaining the regional anomaly.
The analysis for the tracks passing through the Karakoram reveals the role of snowfall as a crucial factor in mass balance estimations.
Calculations by the scientists reveal that contribution of WDs in terms of snowfall volume over the core glacier regions of Karakoram have increased by about 27% in recent decades, while precipitation received from non-WD sources have significantly decreased by around 17%, further strengthening their claims.

Difference between Previous and Current Study

Temperature: Previous studies have highlighted the role of temperature in establishing and sustaining the anomaly over the years.
Precipitation: In the new study, it is for the first time that the impact of precipitation in feeding the anomaly has been highlighted.

Western Disturbances (WDs) & Karakoram–Himalayas (KH)

Western disturbances (WDs) are upper-tropospheric synoptic-scale cyclonic systems embedded in the subtropical westerly jet stream, often associated with extreme rainfall events in northern India during boreal winter.
They are further enhanced over the Karakoram–Himalayas (KH) due to orographic uplift.
WD-associated snowfall is the dominant precipitation over the KH during winter, playing a critical role in establishing and sustaining the regional snowpack and, at the same time, replenishing regional water resources.
The KH region contains the largest glacier mass outside the Arctic and Antarctica. It is often referred to as the “Water Tower of Asia” and is the source of several perennial rivers that flow through the major basins surrounding the “High Asian” region. Even the slightest variation in the annual glacier-melt runoff can have profound impacts on water resources.

Conclusion

The anomaly provides a very bleak but nonetheless a ray of hope towards delaying the inevitable. After recognising the importance of WDs in controlling the anomaly, their future behaviour might very well decide the fate of Himalayan glaciers as well.