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Hi, I'm JD and this week on NASA Now we'll explore NASA's use
of satellites to monitor Climate Change.
But before we get to that,
let's find out what else is happening at NASA NOW!
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NASA's EPOXI mission successfully flew
by comet Hartley 2 recently sending back never before seen
images of the comet nucleus.
This is the second comet that the spacecraft has encountered.
On the original Deep Impact mission back in July 2005,
the spacecraft encountered the comet Tempel 1.
Scientists recently returned to the Southern Hemisphere
where NASA's Operation IceBridge mission has begun its second
year of airborne surveys over Antarctica.
The mission monitors changes in sea ice,
ice sheets and glaciers.
NOW, let's take a look back at the past!
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October 1975, GOES-A, the first satellite
in NOAA's geosynchronous weather satellite system is launched.
Renamed GOES 1 upon reaching orbit,
the satellite continuously monitored weather
until it is deactivated by NASA in 1985.
They say the satellites in NASA's A-Train are helping us
to better understand the Earth system.
Here to fill us in is Dr. Lin Chambers,
Director of the CERES S'COOL Project.
My name is Lin Chambers, I work on a number of projects
that have to do with earth science, atmospheric science
and science education.
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The concept of the Earth as a system is the idea
that when you look at the Earth everything is really connected
to everything else and you can't really look at one part
of the Earth in isolation of everything else.
And so, Earth System Science is just understanding
that you can't just, for example, look at, ok,
we're going to cut down the whole forest in this area
and expect that won't to have an impact on some other things.
It may change the rainfall patterns.
It may change how snow stays or doesn't stay on that surface.
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All aboard!
The A-Train satellite constellation is a group
of satellites that are in very close proximity to each other
in orbit so that they see basically the same part
of the Earth at the same time
or within 15 minutes, or so, of each other.
And that lets us really get at a lot of the earth system process.
Looking at things in the atmosphere, looking at things
on the surface, looking at vegetation,
all within a very short time period
so that we're seeing the same occurrences.
Each of the satellite does have its own focus.
Aqua is looking mostly at the things in the water cycle,
Aura is looking at atmospheric chemistry and pollution,
CloudSat and CALIPSO are looking at clouds and aerosols.
But then they also all work together so by taking the data
from those different areas you can learn, for example,
about the effect of pollution on clouds.
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Aerosols are a pretty important, and not as well understood,
component of the Earth's system and the atmosphere.
And the CALIPSO spacecraft in particular has been looking
at aerosols, and there are some new spacecraft entering the
A-Train that will be helping with that.
Aerosols have a number of different aspects to them.
One, they can reflect sunlight
so they can have a cooling effect on the Earth.
They can also absorb sunlight depending
on what the aerosols are made of
and that can have some interesting effects.
And then, they also have some very complicated affects
on clouds.
So, aerosols serve as cloud condensation nuclei,
that's what the little cloud droplets form around.
So if you have a lot of aerosols you tend
to get smaller cloud droplets and that tends to mean no rain.
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Understanding the Earth
as a system is understanding what we call the energy budget
or the radiation budget of the Earth.
Basically, in order for the Earth to have a stable system
over time where the climate is not changing,
you have to have a balance between the energy coming
in from the sun and the energy that leaves the Earth.
And so, one of the things that we're looking
at is understanding how different parts
of the Earth System control that balance.
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In the S'COOL Project we're asking them
"what clouds are in the sky?"
but we're also asking them "what's on the surface?"
We're asking them "is there snow on the surface?"
Which clearly would change the reflections.
We're asking them "is it raining?"
and then we're asking them about the vegetation on the surface.
Is it currently growing?
In which case, when the satellites looks
down it sees a nice green area, and then we also ask
for information about air temperature,
relative humidity, and pressure.
So, really it is not a complete Earth Systems picture
but it's a pretty good cross disciplinary look at the Earth.
And the reason we do it is
because all those factors affect what the satellite will see
from space.
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Did you know that the Aqua spacecraft carries six state
of the art instruments to observe the Earth's oceans,
atmosphere, land, ice and snow covers, and vegetation?
Aqua is a joint project involving the United States,
Japan, and Brazil.
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Today we learned that by combining the observations
from each of satellite in the A-Train convoy,
scientists are able to gain a better understanding
of connections within the Earth System.
Now it's your turn!
Check out these resources and activities
on the NASA Explorer Schools' Virtual Campus!
This week you and your teammates can visit the Cool Science web
page to learn more about Aqua's mission
and how it helps us better understand the hydrosphere
and it's relationship to other parts of the Earth system.
To access these resources and activities,
visit the NASA Explorer Schools' Virtual Campus
Well that's it for NASA NOW, Join us again next week
when we learn about NASA's Operation "IceBridge,"
We'll see you next time on NASA NOW!
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NASA NOW is brought to you from the Virtual Campus
at NASA Explorer schools.