Real World: Earth Systems


[music playing] – Hi, I’m Mishay for
“NASA eClips,” and today I’m at
the Virginia Living Museum in Newport News, Virginia. Today I’ll be talking with some
NASA scientists to learn more about how
scientists gather information about Earth systems. [music playing] I’m here with Jessica Taylor from NASA Langley Research
Center. Jessica is an atmospheric
scientist. – Hi, Mishay.
It’s nice to meet you. – It’s nice to meet you too. – I understand that you want to
learn more about how NASA scientists gather information
about our earth. – That’s right. For my science class, I learned
that Earth is a part of one big system,
but it also is a part of some smaller subsystems. But I’m not quite sure how all
that works together. – Well, why don’t we go inside
and go to cypress swamp and I can show you a little more
about how these Earth systems interact. As you can see, the Earth
really is a complex system. Changes in one part
of the subsystem can impact the whole planet. Scientists study
the Earth system by looking at multiple spheres. The water here is an example
of the hydrosphere. The air that we breathe is an
example of the atmosphere. The land that you see here, that’s an example of
the lithosphere. And all of these animals– the turtles, the fish,
and the ducks, they’re all part of
the biosphere, living things. And then there’s the cryosphere,
ice. We can’t see that here because
we’re in Virginia, and it just doesn’t get cold
enough here. Scientists keep an eye
on these systems to make sure they’re functioning
as we expect. While scientists look at changes right here at our Earth’s
surface, NASA also uses satellites, with instruments looking back
down at Earth from space. And we use these satellites
to collect data for long-term global
perspective. – So what kind of tools do you
use to look at those changes? – Well, let’s find out more by
talking with a friend of mine, Dr. Steven Pawson. He’s at NASA’s Goddard
Space Flight Center. So let’s come right over here, and we can call Dr. Pawson
directly. [keypad beeping] – Hi, Dr. Pawson. Jessica and I have already
talked about Earth systems, but I don’t understand how these
systems affect climate or how NASA can track that. – Yes, I’m very happy to talk
about that. First, what we know about
climate is that it includes not only
the temperature of Earth but also lots of other things, such as the cycles of carbon
and water. Now, what does NASA do? Because NASA built satellites
that can orbit Earth, it means we can see all places
from space. This gives us a much bigger view
that we can see from the surface alone. So the instruments on NASA’s
satellites help us see the complete Earth
and also measure different parts of the climate system. – So, Steven, can you explain to
Mishay a little more about the tools
that are used to gather this kind of data? And then once NASA has the data, how is that data analyzed
and visualized? – So I think what’s very
interesting is that usually when we’re
measuring from space, we’re actually measuring
the light that’s coming into
the satellite, whether that’s light in the
visible spectrum that we can or whether it’s infrared
or ultraviolet light that we can’t see,
but it’s still part of the electromagnetic
spectrum. And to make real use
of these data, we have to be able to deduce
the quantities that we’re interested in. So we know that if we’re looking
for ice, then if there’s a lot of ice, more light will be reflected; and if there’s not much ice, it won’t be reflected. So in a way that’s a relatively
straightforward measurement. We can detect if there is ice
there or not. But typically, if we’re trying
to deduce the temperature of the Earth from space, then we’re looking at a
different part of the spectrum and we have to be able to
separate impacts of temperature from water vapor and from other
gases in the atmosphere and do what we call a retrieval
of that information. And a retrieval is really using
a lot of complex physical models to try to understand what it is
that we’re observing and what’s causing the change in
the light that we’re measuring. Typically, the physical models
are mathematical equations, but what we actually do is code
them to run on a computer. Instead of reading just one
column of the atmosphere, we’re looking at a grid over
the entire Earth of points, and that includes
the atmosphere, the land, and the ocean. And when we know what the state
is at any one time, we can run those models forward
in time, using very, very powerful
computers. And from those we can deduce
what is going to happen in one day or two days. For instance, we can make
weather forecasts or we can run climate
projections, which are running up to about
100 years ahead. Using this technique,
we’re able to deduce a lot of information about
the surface of Earth and the atmosphere, and even the surface layer
of land and oceans from space. – Thank you so much
to Dr. Steven Pawson and Jessica Taylor. Want to find out more about
Earth systems and the work being done by
NASA and other scientists? Go to this website. That’s all for now. I’m Mishay, and I’ll see you
next time on “NASA eClips.”

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