ngozumpa

If you visit the Himalayas make sure to stop by here. Gokyo with its lakes is worth it. We squeezed in this sunrise hike to the Gokyo Ri (5380m) and had views over four eight-thousander peaks Mt. Everest, Lhotse, Makalu and Cho Oyu. This image shows the Ngozumpa glacier and the six-thousander Cholatse - not less impressive. Can you spot the village of Gokyo?
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Can you believe that THIS is what a glacier looks like? True story - it’s called a supraglacial lake, and it literally sits atop the glacier. There are several types of supraglacial lakes, classified largely by their location within the glacier. “Base-level” lakes are at the hydrological base of the glacier, while “perched” lakes are literally HIGHER than base-level lakes. It is theorized that perched lakes drain into base-level lakes through ice tunnels that run through the glacier.

The biggest supraglacial lake on the Ngozumpa glacier is Spillway Lake, and it is classified as a “moraine-dammed” base-level lake. This means that it rests behind the terminal moraine - the buildup of debris and ice at the glacier’s snout. These types of lakes can be dangerous, because, if the natural debris dam breaks, a massive flood could ensue. These events are called Glacial Lake Outburst Floods, or GLOFs, and have been recorded in Nepal and Bhutan for decades. It’s difficult to predict when a GLOF might occur, and this makes moraine-dammed lakes particularly fearsome.

Dark Snow: From The Arctic To The Himalayas, The Phenomenon That Is Accelerating Glacier Melting:

When American geologist Ulyana Horodyskyj set up a mini weather station at 5,800m on Mount Himlung, on the Nepal-Tibet border, she looked east towards Everest and was shocked. The world’s highest glacier, Khumbu, was turning visibly darker as particles of fine dust, blown by fierce winds, settled on the bright, fresh snow. “One-week-old snow was turning black and brown before my eyes,” she said.

The problem was even worse on the nearby Ngozumpa glacier, which snakes down from Cho Oyu – the world’s sixth highest mountain. There, Horodyskyj found that so much dust had been blown on to the surface that ability of the ice to reflect sunlight, a process known as albedo, dropped 20% in a single month. The dust that was darkening the brilliant whiteness of the snow was heating up in the strong sun and melting the snow and ice, she said.

The phenomenon of “dark snow” is being recorded from the Himalayas to the Arctic as increasing amounts of dust from bare soil, soot from fires and ultra-fine particles of “black carbon” from industry and diesel engines are being whipped up and deposited sometimes thousands of miles away. The result, say scientists, is a significant dimming of the brightness of the world’s snow and icefields, leading to a longer melt season, which in turn creates feedback where more solar heat is absorbed and the melting accelerates.

In a paper in the journal Nature Geoscience, a team of French government meteorologists has reported that the Arctic ice cap, which is thought to have lost an average of 12.9bn tonnes of ice a year between 1992 and 2010 due to general warming, may be losing an extra 27bn tonnes a year just because of dust, potentially adding several centimetres of sea level rise by 2100. Satellite measurements, say the authors, show that in the last 10 years the surface of Greenland’s ice sheet has considerably darkened during the melt season, which in some areas is now between six and 11 days longer per decade than it was 40 years ago. As glaciers retreat and the snow cover disappears earlier in the year, so larger areas of bare soil are uncovered, which increases the dust erosion, scientists suggest.

Research indicates that the Arctic’s albedo may be declining much faster than was estimated only a few years ago. Earlier this year a paper in Proceedings of the National Academy of Sciences reported that declining Arctic albedo between 1979 and 2011 constituted 25% of the heating effect from carbon dioxide over the same time.

According to Danish glaciologist Jason Box, who heads the Dark Snow project to measure the effect of dust and other darkening agents on Greenland’s ice sheet, Arctic ice sheet reflectivity has been at a near record low for much of 2014. Even a minor decrease in the brightness of the ice sheet can double the average yearly rate of ice loss, seen from 1992 to 2010.

“Low reflectivity heats the snow more than normal. A dark snow cover will thus melt earlier and more intensely. A positive feedback exists for snow in which, once melting begins, the surface gets yet darker due to increased water content,” says Box on his blog. Both human-created and natural air pollutants are darkening the ice, say other scientists.

Nearly invisible particles of “black carbon” resulting from incomplete combustion of fossil fuels from diesel engines are being swept thousands of miles from industrial centres in the US, Europe and south-east Asia, as is dust from Africa and the Middle East, where dust storms are becoming bigger as the land dries out, with increasingly long and deep droughts. Earlier this year dust from the Sahara was swept north for several thousands miles, smothered Britain and reached Norway.

According to Kaitlin Keegan, a researcher at Dartmouth College in the US state of New Hampshire, the record melting in 2012 of Greenland’s northeastern ice-sheet was largely a result of forest fires in Siberia and the US.

Any reduction in albedo is a disaster, says Peter Wadhams, head of the Polar Oceans Physics Group at Cambridge University.

He said: “Replacing an ice-covered surface, where the albedo may be 70% in summer, by an open-water surface with albedo less than 10%, causes more radiation to be absorbed by the Earth, causing an acceleration of warming. "I have calculated that the albedo change from the disappearance of the last of the summer ice in 2012 was the equivalent to the effect of all the extra carbon dioxide that we have added to the atmosphere in the last 25 years,” he says.

UlyanaHorodyskyj, who is planning to return to the Himalayas to continue monitoring dust pollution at altitude, said she had been surprised by how bad it was.

“This is mostly manmade pollution,” she said. “Governments must act, and people must become more aware of what is happening. It needs to be looked at properly.”

Gokyo, Nepal at Night

Jeff: “The night at Gokyo is the most relax moment during my Everest Base Camp journey. Here is the view just 2 minutes from the hotel. The winter Milky Way with bright Sirius, Orion and Aldebaran shine above the moonlight mountainscape of Phari Lapche. I also enjoy the calm view of Lake Dudh Pokhari with the reflections of the stars and snow peak.”

Gokyo Ri, aka Gokyo Peak (5,357 m, 17,575 ft above sea level), is a peak in the Khumbu region of the Nepal Himalayas. It is located on the west side of the Ngozumpa glacier, which is the largest glacier in Nepal and reputed to be the largest in the whole Himalayas. Gokyo (4,750 m, 15,583 ft above sea level), at the base of Gokyo Ri, is a small hamlet of a few stone houses and one of the highest settlements in the world. From Gokyo Ri it is possible to see four 8,000-meter peaks. (Source: Wikipedia)

Credit: Jeff Dai

Location: Gokyo, Nepal

Date: December 7, 2015

#Space #Astronomy #Science #Stars #MilkyWay #Galaxy #Stars #Sirius #Orion #Aldebaran #Himalayas #Mountains #Gokyo #Nepal #नेपाल #Astrophotography #Art #Science #SolarSystem #Cosmos #Universe

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