Worrying case of the majestic Gangotri glacier

A research shows that the health of the majestic Gangotri glacier that feeds the river Ganges has been affected, as the maximum temperature in the region has shot up by 0.9 degree Celsius and snowfall reduced by 37 cm annually.

A team of climate scientists recorded and analysed snow and meteorological parameters for a period of 13 years from 2000 to 2012 and found a warming trend.

"Maximum and minimum temperature reveal an increase of 0.9 degree Celsius and 0.05 degree Celsius respectively during the decade. Annual snowfall amount reveals a decrease of 37 cm in the decade," says the report from the Snow and Avalanche Study Establishment, Chandigarh.

The report would soon be published in the Current Science journal.

Scientists from the institute, part of the Defence Research and Development Organisation under the defence ministry, were based at 'Bhojbasa' observation station, nearly 5 km south from the Gangotri glacier snout named 'Gaumukh', to record the findings.

"We know that the glaciers, including the Gangotri, have been receding over the last few years. In this report we tried to corroborate it with meteorological data. It shows the effect of climate change," scientist H S Gusain, lead author of the five member team who did the study, told PTI.

Situated in Uttarakhand district, the 30.2 km-long Gangotri glacier is the second largest in India.

One of the primary sources of fresh water supply to the river Ganges, Gangotri has been found to have retreated more than 1,500 metres in the last 70 years.

The Intergovernmental Panel on Climate Change has found that global surface temperatures have risen by almost a degree in the last century.

"These snow–meteorological parameters have a significant bearing on glacier accumulation/ablation pattern, and will influence glacier retreat and advancement," says the report.

The Western Himalayas have already shown a similar trend of increasing temperature and decreasing snowfall.

The maximum temperature in the Gangotri region varies from 9.8 degree to 12 degree C with a mean value of 11.1 while minimum temperature varies from –1.5 degree C to –2.9 degree C with mean value of –2.3, according to the study.

The highest values of maximum and minimum temperatures are observed for monsoon season as incoming solar radiation is observed to be the highest during this season.

High temperatures may cause higher melting rate of the glaciers in the region during the monsoon season, the scientists say.

During winter, snowfall in the region is mainly due to western disturbances.

In the report, year 2002 was observed to be one with the highest snowfall of 416 cm, while 2004 and 2009 were observed with the least snowfall of 156 and 137 cm respectively.

2004 was observed to be the warmest year during the last decade in the report.

Photograph: Arpit Rawat/Wikimedia Commons