Over the past few days, we've seen a significant amount of actually liquid
water on the surface that has both accumulated in small ponds and
probably approaching the size of lakes, especially near the edge of the ice sheet.
Last spring, flying over the southern Greenland Ice Sheet,
NASA’s Operation IceBridge witnessed signs
of the second-earliest onset of surface melt recorded in the 40 years of the satellite record.
An interesting thing is that the melt season actually in Greenland started
pretty much end of April beginning of May, which in the grand scheme
of things is very close to a month earlier than, than average.
My name is Brooke Medley. I'm the Deputy Project
Scientist for Operation IceBridge. Last April
and May, we were actually flying in Greenland out of
Kangerlussuaq on the NASA P-3. This was
somewhat of a unique year where we expected
to be going early enough where we would see the typical
dry snow conditions. But rather we were met with
a much different scenario where we saw all these spectacular
blue ponds of beautiful liquid water just pooling
on top of the surface. The ice sheet is actually
experiencing almost an additional month of melt because it
started so early here, part of it is actually driven by the fact that
it's very warm right now, but also that there was not a lot of
snowfall last winter. And so what that means is,
when the, the snow does melt it very quickly exposes darker
ice, which can then melt even faster.
It went from pretty much frozen over at the surface,
just before the melt started to completely unfrozen
and the rivers have risen and there's just a significant
increase in the total amount of water that we just see in general.
Over the course of 2019,
there was so much melt that it actually ended up being
the second-largest meltwater production year
for the Greenland Ice Sheet since 1980. What does it mean for
2020 is an excellent question. So what happens
when you have a an extreme melt year is that it can often impact
a subsequent season. So it's definitely something we
were looking for coming into the 2020 season is,
are we going to be seeing another 2019 because we've
preconditioned the ice sheet to be more susceptible
to melt and, and interestingly, right now, 2020 is
trending along a more normal trajectory for melt.
That being said, this is still just July and the biggest
pulse of meltwater from 2019 actually occurred
at the end of July beginning of August, so there's still a lot of melt
season left to go. It's actually quite simple
-- the longer your melt season that means you can just have more time to accumulate more melt
and the only place for this water to go is into the ocean,
so it will be driving sea level rise, and Greenland is
currently, outside of the thermal expansion of the ocean, is
the largest contributor to global sea level rise.
EXPLORE EARTH
NASA