Everest glaciers lose mass in winter too, says study
- Everest glaciers retreat even in winters
- Snow loss much less than Alps
- The study plugs holes in Himalayan glacier studies
The study, conducted for five years since 2007 on Mera and Pokalde glaciers, is one with the longest field observations of annual glacial mass balance in the region and was published in November in The Cryosphere journal.
The study found evidence of ablation – removal of snow and ice – at all levels in the Everest region in winter, due to wind erosion, and snow and ice turning into water vapour.
However, the rate of snow loss is three to four times lower than that in the European Alps, it says.
Himalayan glaciers have evoked global interest after the furore over an inaccurate statement in the fourth assessment of the Inter-Governmental Panel on Climate Change (IPCC) in 2007 that they would disappear in a few decades, at the current levels of global warming.
“Annual glacial mass balance measurements allow us to tie changes in glacial mass to important climate signals; through it we came up with the finding that ablation happens in the winter time here as well,” Joseph Michael Shea, co-author of the study and glacial hydrologist at the Integrated Centre for International Mountain Development (ICIMOD), Kathmandu, told SciDev.Net.
Rijan Bhakta Kayastha, coordinator at the Himalayan Cryosphere, Climate and Disaster Research Center (HiCCDRC), says that although snow loss has been observed during winter, more measurements of various climate-related factors linked to snow loss are needed to reach a concrete conclusion, a limitation that the study too acknowledges.
Patrick Wagnon, lead author of the study and visiting scientist at ICIMOD, plans to maintain Mera glacier as a monitoring site for long-term glacial mass balance studies, and include it in the GLACIOCLIM network - a worldwide monitoring network that aims to study the relationship between glaciers and climate. The Mera glacier initiative aims to end a long-standing problem of inconsistency in glacier studies in the Himalayan region, which has made it difficult for scientists to build models to quantify snow transportation.
“It is a huge problem because we really do not know how much snow falls in high elevations, where it snows more or less and what the distribution is, so it is hard to say much about accumulation zones,” adds Shea.
The future direction of glacial studies in the Himalayas would be to build long-term climate records from chosen sites such as Mera and study relationship between the onset of monsoon and the annual glacial mass balance data, according to authors.
Link to paper published in the Cryosphere.net