NASA's operation to track Greenland's melting ice ++UPDATED SCRIPT++

(21 Aug 2019) LEAD IN

A World War Two plane stacked with science equipment is helping NASA to launch probes hundreds of metres under Greenland on a mission to track melting ice.

Greenland's ice sheet is melting six times faster than it was 20 years ago and this summer has experienced two of the biggest melts on record since 2012.



STORY-LINE:

It's take off on the latest leg of NASA's Mission OMG - which stands for Oceans Melting Greenland.  

The Arctic island is melting faster than ever before. According to NASA, this month, it lost 11 billion tons of surface ice in one day - enough to fill more than four million Olympic-sized swimming pools.

It's down to global warming but NASA scientists are trying to get to the bottom of exactly what's causing it.

It's year 4 of a 5 year mission and lead scientist on the project, Josh Willis and his team have commissioned an old DC-3 war plane for this week's mission.  

"This airplane is really exiting to work on because it's an old DC-3 that's been rebuilt just this last couple of years. It was originally built in 1942 for WW2 and  since that time they've put new wings, new engines on it and it's been repurposed for science. It does a really fantastic job for us. Landing on all these tiny airports and we can carry a huge amount of cargo. (Pointing to boxes). So each of these giant blue boxes is filled with probes, which we are dropping into the ocean and using to measure just how much the oceans are warming and how that affects glaciers. (Turns) These two racks are equipment racks. This one's filled with radios and recorders and also a decoder which takes the radio signal from the probe and turns it to temperature and conductivity data," says Willis.

In a typical glacier, a layer of warm, salty water sits below a colder, fresher layer on the surface.  It's this warmer, saltier water that reaches into the fjords, melting the edges of the glaciers.

Warmer air above the surface is also eating away at the glaciers.

Together the warm air above and the warm water below are causing Greenland to lose billions of tons of ice daily in the summer.  

Part of the OMG mission is to drop probes into the ice to help figure out which is the bigger cause  - warm air or warm water.

"We have 3 different kinds of these probes. Each one transmits on a slightly different frequency. That allows us to listen to up to 3 probes at a time," says Willis.

Each year the OMG team drop around 250 probes deep into the ice melt.

The probes measure temperature and salinity before radioing back data to the team. This helps the scientists track how much warm water from the Atlantic is eating away at the glaciers from below as well as how the warm air is attacking them from above.

"It has gone all the way down to 700 metres and it'll probably go to 8, it might even go to a thousand. A few of these fjords are that deep. But when it terminates. you'll see a jump in the conductivity. That's because the little probe has hit some (inaudible). Mud has gotten into it. It will get way less conductive and that's one of the ways we know we've hit the bottom."

As part of OMG, annual surveys have also been measuring the height, thinning and retreat of the glaciers. If at the end of the 5 year mission, the collated results show that water is playing a bigger role than the scientists currently think, it could mean that seas will rise faster than predicted.

And that would spell bad news not just for Arctic, but for populations all around the world.  



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