[ Slate ]
Well the latest images are telling us that number one it's
been a really warm winter in the Arctic. It's been warm around the globe, but it's been
really warm in the Arctic - record setting warmth. And we've seen that
in the sea ice, which is at one of its lowest levels at this time of year
in the satellite record going back over 35 years. The ice is also
very thin. [ Slate ]
So the difference between sea ice and land ice is that sea ice grows and melts
within the ocean as the ocean cools. Land ice forms
on land because snow falls on it and gets compressed into ice
over time. One of the big differences in the effects of those is that sea ice
because it grows and melts in the oceans does not raise sea level.
It's the land ice and the land ice that melts that is raising sea level.
Sea ice has a big effect on climate though because it reflects
solar energy because of its whiteness compared to the dark ocean. So
sea ice is very important for the climate as well just not for sea level
[ Slate ] The reason we care is because first of all
changes that are happening there, are happening. They're the first indication
of the warming that we're seeing and the most dramatic so far that we're seeing. But they're an indication
of what's coming to the rest of the globe. But it also has an
affect even now because the changes that happen in the
Arctic with the sea ice, it changes the atmospheric circulation patterns. It changes the
the weather patterns and that effect, that doesn't stay
in the Arctic. What happens in the Arctic doesn't stay in the Arctic.
[ Slate ]
Every year the ice goes
it varies from year to year due to the weather, due to natural cycles
but over the 35 plus years now we've seen a very significant downward
trend where every year tends to be lower than the previous year.
[ Slate ]
NASA is launching two missions to the Arctic - Operation IceBridge and
Oceans Melting Greenland. These two missions are
focused on Greenland and the Arctic sea ice. They're
aircraft missions to better understand what is going on in the
Arctic and why these changes are happening and why they're happening so rapidly.
We have a lot of data that we can see these changes happening, but we've also
been surprised by a lot of these changes and we still need to better understand
the processes that are going on and these NASA missions will help
us get the data to better understand what's going on
and what will happen in the future and the impacts of these dramatic changes
in the Arctic and on the rest of the globe. [ Slate ]
You can learn more
about all of the activities going on in the Arctic Operation IceBridge
Oceans Melting Greenland and all of NASA's data and activities at
nasa.gov/Earth or on Twitter @NASAEarth.