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Of all of the instruments in NASA's
Earth Observing System, MODIS has proven to be one of the most versatile,
producing both groundbreaking science and compelling images.
The Moderate-resolution Imaging Spectroradiometer,
on both the Aqua and Terra satellites, has changed the way we look
at our atmosphere, oceans, and land.
KING: MODIS increased the wavelength range, covered more
physical properties of the environment that it could monitor,
it measured them down to as small as 250 meters, the size of a couple of football fields,
in size. And had many more spectral bands to
study more aspects of ocean biology, of the land,
fires, and it was a very technological
advance. And for a long time
in the EOS community, it was referred to
as the quintessential instrument of the EOS because it did more things for more people,
more disciplines than any other single instrument.
NARRATION: The study of clouds is, not surprisingly, incredibly important for understanding
weather and climate. And until MODIS came along,
it was commonly accepted that at any given time the Earth was about 50 percent covered by clouds.
But data from the instrument showed that cloud cover
was actually closer to 70%.
MODIS can also measure the temperature and height of clouds, and differentiate
between clouds composed of liquid water, a¬nd those made of ice.
MODIS also monitors the world’s oceans, measuring sea surface
temperature, ocean color and clarity, and the basis of the
marine food chain, phytoplankton.
KING: MODIS has done a very good job of getting this biological signature.
Chlorophyll A, which follows phytoplankton, ocean currents.
You can see the seasonal variation
due to El Niño and other things where the biological productivity of the ocean.
This is important because this biological photosynthesis
takes carbon dioxide out, produces oxygen as part of photosynthesis,
and so it is a sink for carbon that we, Man, put in the atmosphere.
NARRATION: MODIS also looks at the land, monitoring fires,
land use change, and various measures of the Earth’s plant life.
KING: So it’s been used for a long time to monitor
the growth of vegetation, the seasonal cycle, and how that
year-to-year, whether it’s due to droughts, associated with El Niño
or the spread of the Sahara, but it’s a very good index to monitor.
NARRATION: The versatility of MODIS,
as it measures land, sea, and air, contributes to the wealth of information
being revealed by the Aqua mission.
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