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Kurtz: So we’re looking at data that’s just
north of Greenland and Ellesmere Island. So there’s a very
narrow passage called the Nares Strait, and an ice arch forms there most
years, and it broke up very early this year.
So what we’re seeing in the data is ice that’s very smooth and flat.
This is new ice that had grown as the ocean had been exposed, and then
we’re seeing a lot of the thick, older, ridged ice. That’s these photon
clouds that look a bit rougher. And so what we’re doing with ICESat-2
is really looking for thickness changes in the ice.
So the Arctic icepack has been thinning quite a bit. It’s lost about half its thickness
since the 1980s when we measured it with submarines.
And so what we’re looking at is measuring changes in the thickness of the ice.
And then that change in the sea ice, that has an impact on the
overall climate of the Earth. The polar regions act as an air conditioner
for the planet. Because when there’s sea ice there—especially snow-covered sea
ice—it reflects a lot of the Sun’s energy and so that helps keep the planet cool.
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