Why is it important to watch forests from space?
A forest in Davis, West Virginia. Photo by Darshan Vaishnav (Flickr Creative Commons)
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 new satellite will launch that will give scientists new ways to watch these trees. The satellite is called JPSS-1—short for Joint Polar Satellite System. It will be known as NOAA-20 once it reaches orbit.
JPSS-1 will have 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 as seen from the AHI instrument aboard the Japan Meteorological Agency’s Himawari-8 satellite. Credit: CIRA/NOAA/JMA/JAXA
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.