The Short Answer
Scientists use satellite information to detect the health of forests during droughts and other severe weather events. Trees are an important part of the carbon cycle, so satellite information can help us understand more about that as well.
When leaves change from deep green to bright red, it’s more than just a beautiful display for us to enjoy. Scientists can learn from these changes and study trees and forests. And since trees are an important part of the carbon cycle, it helps us understand more about that as well.
In much of the western United States, there is a serious drought. It’s taking a toll on trees, and even from space, the forests look noticeably less green than usual. Extreme drought can even kill large parts of forests. Scientists can see this happening from space and give forest managers more information about upcoming fire seasons. This is important because dead trees burn much more easily than living ones.
We can also monitor forests that are in danger because of human development, especially in places like the Amazon Rainforest.
In 2017, a satellite launched that will gave scientists new ways to watch these trees. The satellite is called JPSS-1—short for Joint Polar Satellite System. It was known as NOAA-20 once it reached orbit.
JPSS-1 has an instrument called the Visible Infrared Imaging Radiometer Suite, or VIIRS. With it, scientists can watch forests over time in great detail.
About 75 percent of Earth is covered by ocean water. From a satellite’s perspective, this looks like most of the planet is an unchanging mass of blue. VIIRS helps scientists take a closer look at the 25 percent of Earth that is green.
Full-disk, true color image of the Earth. Credit: CIRA/NOAA
The VIIRS instrument can detect chlorophyll, which is the pigment that makes plants green. Not only will it be able to detect green, but the VIIRS sensor will even be able to tell the difference between shades of green. This can tell scientists which areas are lush with plants, and which areas were hit hard by drought, wildfires, or heavy snow.
True color imagery from the VIIRS instrument aboard the NOAA/NASA Suomi NPP satellite. The northeastern United States and southeastern Canada in early fall, before the leaves have changed (left), and the same region after the leaves have changed (right). The red arrows indicate where lush green forests (left) have changed to autumn colors (right). Credit: Curtis Seaman/CIRA
With all this information, scientists can track forest health, learn more about the carbon cycle, forecast upcoming wildfires, and a lot more. And the pictures that JPSS satellites take give us all a new view of Earth’s beautiful landscape throughout the year.
Keeping an Eye on Crops
Although satellites orbit high above Earth, they allow scientists to monitor lots of things that affect your everyday life. The JPSS-2 satellite helps scientists track changes in forests, the weather outside, and even changes in the crops that grow our food.
VIIRS can help scientists to estimate the health and condition of crops which is especially important during extreme weather conditions such as drought. The instrument can also estimate how these changes will affect the crops’ anticipated yield (the quantity of food the plants will produce).
This information can help farmers, scientists, and policy makers better understand how changes in weather can affect the productivity of crops.