NASA’s ECOSTRESS instrument on June 19 recorded scorching roads and sidewalks across Phoenix

Data for this visualization of the Phoenix area — the fifth most populous city in the United States — was collected at 1:02 p.m. local time on June 19, 2024, by a NASA instrument aboard the International Space Station. Called ECOSTRESS (short for the Ecosystem Spaceborne Thermal Radiometer Experiment on Space Station), the instrument measures thermal infrared emissions from Earth’s surface.

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“We create these maps to be intuitive to users and help make data more accessible to the public and citizens scientists,” said Glynn Hulley, a JPL climate researcher. “We see them as a vital tool for planning effective heat interventions, such as tree planting, that can cool down the hottest roads and sidewalks.”

Homing in on Heat
At the lower right of the image is Phoenix’s Sky Harbor International Airport, where ECOSTRESS recorded some of the hottest land surface temperatures within the city —around 140 F (60 C). 

The air temperature on June 19 at the airport reached 106 F (43 C).

Air temperature, which is measured out of direct sunlight, can differ significantly from the temperature at the land surface. 

• Streets are often the hottest surfaces of the built environment due to dark asphalt paving that absorbs more sunlight than lighter-colored surfaces; asphalt absorbs up to 95% of solar radiation. 
• These types of surfaces can easily be 40 to 60 degrees F (22 to 33 degrees C) hotter than the air temperature on a very hot day.

Launched to the International Space Station in 2018, ECOSTRESS has as its primary mission the identification of plants’ thresholds for water use and water stress, giving insight into their ability to adapt to a warming climate. But the instrument is also useful for documenting other heat-related phenomena, like patterns of heat absorption and retention.

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News Flash: ECOSTRESS has received approval for operations through FY2026 with potential continued operations until FY2029, subject to a successful 2026 Senior Review!

News Flash: ECOSTRESS has now acquired over 450,000 scenes (after In Orbit Checkout)

Announcement, Save the Date: "2024 IEEE International Geoscience and Remote Sensing Symposium" - IGARSS 2024 in Athens, Greece on July 7 - 12

ECOSTRESS is addressing  three overarching science questions:

• How is the terrestrial biosphere responding to changes in water availability?
• How do changes in diurnal vegetation water stress impact the global carbon cycle?
• Can agricultural vulnerability be reduced through advanced monitoring of agricultural water consumptive use and improved drought estimation?

The ECOSTRESS mission is answering these questions by accurately measuring the temperature of plants.  Plants regulate their temperature by releasing water through tiny pores on their leaves called stomata.  If they have sufficient water they can maintain their temperature, but if there is insufficient water, their temperatures rise and this temperature rise can be measured with ECOSTRESS.  

• The images acquired by ECOSTRESS are the most detailed temperature images of the surface ever acquired from space and can be used to measure the temperature of an individual farmers field.

One of the core products that will be produced by ECOSTRESS team is the Evaporative Stress Index (ESI). 

• ESI is a leading drought indicator - it can indicate that plants are stressed and that a drought is likely to occur providing the option for decision makers to take action.

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To produce the image of Phoenix, scientists used a machine learning algorithm that incorporates data from additional satellites: NASA/USGS Landsat and Sentinel-2. 

The combined measurements were used to “sharpen” the surface temperatures to a resolution of 100 feet (30 meters) by 100 feet (30 meters).

More About the Mission
JPL 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.

More information about ECOSTRESS is available here: https://ecostress.jpl.nasa.gov/.