The Western United States has been entrenched in an Extreme and Exceptional drought that has extended from the summer and into the fall of 2020. NASA's ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) imaged the drought on Oct. 16, 2020, and compared the same area to an image from ECOSTRESS taken a year earlier on Oct. 16, 2019. The bottom image shows the percentage change in plant water stress from 2019 to 2020.
The images at left zoom into the Arizona and New Mexico border and Navajo Nation Territory area, featuring the ECOSTRESS Evaporative Stress Index (ESI), which shows plant water stress. The inset images on the right zoom further into the region, showing circular agricultural fields that have been irrigated. Blue colors represent low stress and high water use, whereas red colors represent high stress and low water use. Irrigation is able to alleviate plant water stress in many of the fields while the surrounding landscape suffers from the drought, though numerous agricultural fields are shut down in the drought image.
The primary mission of ECOSTRESS, which launched to the International Space Station in June 2018, is to provide insight into plants' health, especially in a drought, by taking their temperature. Plants regulate their temperature by releasing water through tiny pores on their leaves. With sufficient water, they can maintain their temperature. When they lack water, their temperatures rise; ECOSTRESS can measure this change.
Managed by Caltech in Pasadena, California, NASA's Jet Propulsion Laboratory built and manages the ECOSTRESS mission for the Earth Science Division in the Science Mission Directorate at NASA Headquarters in Washington. ECOSTRESS is an Earth Venture Instrument mission; the program is managed by NASA's Earth System Science Pathfinder program at NASA's Langley Research Center in Hampton, Virginia. Future studies could use ECOSTRESS data products in a similar fashion as ESI was used to assess the drought pictured above.
More information about ECOSTRESS is available here: https://ecostress.jpl.nasa.gov/.
For information on Earth science activities aboard the International Space Station, visit: http://www.nasa.gov/issearthscience.