Greenland Ecological Monitoring Program's Treasure Trove of Arctic Research Data Publicly Available

By: Catherine Jex, Journalist for ScienceNordic.com

Editor's Note: This article is based on one published online by ScienceNordic on 15 November 2017, "Treasure trove" of Arctic research data now publicly available, also written by Catherine Jex.

The Greenland Ecosystem Monitoring program (GEM) was established in 1994 by research institutions throughout Denmark and Greenland to conduct long-term inter-disciplinary data collection. As part of the program, scientists have been collecting data on snow cover, wind, rain, temperatures, fjord water chemistry, glaciers, and populations of musk oxen, spiders, insects, birds, and more from around Greenland for decades. By visiting the same locations to sample the same characteristics with the same methods year after year, they have steadily built a valuable database.

"It is laborious and repetitive work but the result is a treasure trove of data that is helping scientists from across the world to better understand changes in the Arctic," says program leader Torben Røjle Christensen from Aarhus University, Denmark. "We now have a twenty-year record of operational data that cannot be found anywhere else in the circumpolar north. As a coordinated program, it's unique."

Take a tour of an Arctic monitoring site.

Free Data for Researchers, Students, or Interested Citizens

All of the data are now freely available on the GEM data website and a summary of the most significant discoveries from the past year is available in the recently launched Annual Report Cards.

GEM has 180 registered users from around the world—mainly researchers who are aware of the program. Now, the goal is to reach the education sector, says Christensen, who hopes that university students and school teachers will use the data. "Anyone can go in and download the data. There's a boatload available," says Christensen, "more than 1,500 parameters to be exact."

Below are four recent discoveries from the GEM program.

1) Glacial Melt from Greenland is Making the Sea Fresher

A recent study presented the first long data series documenting the impact of melting ice on the water chemistry of a fjord in north east Greenland.

One question posed by climate change is "will melting land ice and sea ice in the Arctic slow down or even shut down a vital part of the ocean circulation in the North Atlantic?" The consequences of that outcome could be severe and possibly even cut off the supply of mild, wet weather to north and west Europe. Whether or not this is already under way is a contentious topic, but one clear indication would be a long-term reduction of temperature and salinity in the seas around Greenland.

"This is just what we saw," says lead-author Mikael Sejr from Aarhus University, Denmark. "We looked at two of the most basic parameters, it's as simple as it gets: the temperature and salinity of water in a Greenland fjord. But it's a game changer," says Sejr.

Sejr and colleagues studied GEM data collected over 13 years and saw a four-fold increase in the fresh water contributions to the Young Sound in Northeast Greenland that were associated with melting glacier ice further north.

"It isn't surprising, but it's the first long data series to show it," says Sejr. The next step is to see how far this freshening extends in the seas around Greenland, he says.

Read More: Is a vital pattern of ocean circulation about to shut down?

2) Greenland's Glaciers are Melting Faster than the Ice Sheet

Independent of the Greenland ice sheet, there are approximately 19,000 individual glaciers on Greenland. Scientists are monitoring five of these, three of which are part of the GEM network.

These 19,000 glaciers cover a relatively small area—just 5% of all ice-covered land in Greenland—but studies over the past decade, using monitoring data from GEM among others, indicate that they contribute up to 14% of all ice loss from Greenland.

Some of these glaciers terminate in fjords, where a recent study demonstrated their importance for maintaining some of Greenland's most productive fisheries.

"We see that the most productive halibut fisheries are located close to marine-terminating glaciers," says lead-author Lorenz Meire from the Greenland Climate Research Centre (GCRC) at the Greenland Institute of Natural Resources in Nuuk, Greenland. "Today, productivity in these fjords is stimulated by these types of glaciers, but this will all change in the future as they retreat on land," he says. The results contradict the more positive picture often painted of the economic benefits expected for fisheries. For example, as fish migrate north into warmer waters and new Arctic shipping routes and fisheries open up as sea ice continues to retreat.

3) Frozen Soils "Push" Methane Out of the Tundra

Shortly after the Zackenberg Research Station was established in Northeast Greenland, scientists observed a phenomenon that had never been seen before: frozen tundra releasing more greenhouse gas than thawing tundra.

We often hear that thawing permafrost is a ticking time bomb that could release large quantities of greenhouse gases into the atmosphere, further exacerbating global warming. But the ability of frozen soils to emit large quantities of methane gas was entirely new.

"Nobody knew this before. We first had a chance to measure it in 2007 and 2008, and since then it's received a lot of scientific attention," says GEM program leader Christensen, who has subsequently observed similar events in Alaska and Svalbard.

Their measurements at Zackenberg showed that more methane was released during a single event than during all of the previous summer. It was caused by frozen soils sitting above permafrost, which created enough pressure to "push" the methane out of the tundra. Subsequent monitoring showed the effect to be much smaller and variable in the following years.

"It doesn't happen every year, so we need to have these long time series to see these events. Otherwise, we don't have a complete picture," says Christensen.

Read more: One quarter of the Arctic is a hotbed for overlooked greenhouse gas.

4) The Arctic is More Dynamic than Previously Thought

Scientists have captured other extreme events as part of the GEM network.

On 11 April 2016, a series of avalanches occurred across Kobberfjord, just outside Nuuk in Southwest Greenland. The events were triggered by a period of intense rainfall and a rapid rise in temperatures, which rose by 27˚C in a little over two days. This initiated a flow of slushy snow, churned up with mud, rocks, and vegetation, in what the scientists called a slush flow.

The event caused the water level of a nearby lake to rise rapidly to its second highest level on record and took out some of the monitoring equipment installed at the Nuuk site.

"We coincidentally observed this rare event during one of our regular monitoring tours and are now benefiting from the wealth of ground-based GEM data available during this period," says Jakob Abermann from Asiaq Greenland Survey, and the lead scientist of ClimateBasis—the climate monitoring sub-program of GEM.

Abermann and colleagues are now assessing the spatial scale of this event using high-resolution satellite images, and have since identified several hundred other similar slush flow from the same event.

Further information about GEM and other GEM projects is available on the GEM website.