\n<\/p>\n
On May 21, ground controllers powered down NASA\u2019s AWE (Atmospheric Waves Experiment) instrument, bringing the data collection phase of the mission to a successful and scheduled end, surpassing its planned two-year mission.<\/p>\n
Installed on the exterior of the International Space Station since November 2023, AWE studied atmospheric gravity waves, which are giant ripples in the atmosphere caused by strong winds flowing over tall mountains or by violent weather events, such as tornadoes, thunderstorms, and hurricanes. The AWE instrument looked for these waves in colorful bands of light in Earth\u2019s atmosphere, called airglow. Funded by NASA\u2019s Heliophysics Division, AWE investigated how atmospheric gravity waves propagate upward to space and contribute to space weather \u2014 conditions in space that can disrupt satellites, as well as navigation and communications signals.<\/p>\n
\u201cThe AWE mission has proven that our atmosphere is not a ceiling, but a living, breathing ocean in the sky,\u201d said Joe Westlake, director of NASA\u2019s Heliophysics Division at NASA Headquarters in Washington. \u201cFor the first time, we can see how a thunderstorm in the Midwest, a hurricane over Florida, or a wind gust over the Andes sends invisible ripples \u2014 atmospheric gravity waves \u2014 crashing into the edge of space like waves hitting a shoreline. By mapping these ripples from the International Space Station, we\u2019ve discovered that Earth\u2019s weather doesn\u2019t just end at the clouds, instead it reaches out beyond our planet, shaping the space weather that impacts our orbital economy.\u201d<\/p>\n
During AWE\u2019s 30-month residency on the station, the instrument captured four infrared images every second, tallying more than 80 million nighttime images, which is when airglow can be seen. It observed atmospheric gravity waves from numerous extreme weather events, including a tornado outbreak across the central U.S. in May 2024 and Hurricane Helene impacting the gulf coast of Florida in September 2024.<\/p>\n
\u201cWe\u2019ve seen atmospheric wave signatures associated with major terrestrial events, which provided a clear example of how intense weather systems can generate measurable upper-atmospheric responses,\u201d said AWE\u2019s principal investigator, Ludger Scherliess of Utah State University in Logan.<\/p>\n
These events revealed variations in the types of atmospheric gravity waves created by different kinds of storms. For example, when AWE viewed atmospheric gravity waves generated by a thunderstorm in north Texas on May 26, 2024, it saw they were smaller and more irregular, with a notable asymmetry from north to south, compared to waves created by storms in the same part of the country earlier that month.<\/p>\n
It is important to understand variations in the density of plasma, which is electrically charged gas, in Earth\u2019s upper atmosphere instigated by atmospheric gravity waves, because these variations can disrupt radio signals traveling between satellites and the ground, and from satellite to satellite, degrading the accuracy and reliability of systems used for navigation, timing, and communications.<\/p>\n
In a recent study, AWE measurements also revealed the gravity waves with the greatest influence on the upper atmosphere have small horizontal wavelengths, ranging from 30 to 300 kilometers, which AWE was specifically designed to measure.<\/p>\n
With its data-collection phase complete, the AWE instrument was turned off to make way for another science experiment that will take its place on the outside of the space station. Called CLARREO Pathfinder (Calibration\u00a0Absolute Radiance and Refractivity Observatory Pathfinder), the new instrument will take measurements of sunlight reflected by Earth and the Moon that are five to 10 times more accurate than those from existing sensors. The exchange of instruments is a key part of the space station\u2019s mission and versatility as an orbiting laboratory for various types of research.<\/p>\n
In the coming days, a robotic arm on the space station, called Canadarm2, will remove the AWE instrument from its location. Soon afterward, the AWE instrument will be loaded into part of a SpaceX Dragon cargo spacecraft that will deorbit and burn up as it re-enters the atmosphere. However, all of AWE\u2019s observations will ultimately become available to the public and the scientific community for ongoing research and discovery.<\/p>\n
\u201cData from AWE will continue to be made public for both professional researchers and citizen scientists,\u201d Scherliess said.<\/p>\n
Some of this data already is available, including interactive, online visualizations on Utah State University\u2019s website, where AWE\u2019s observations are \u201cpainted\u201d in swaths onto a globe or on a map as the space station orbits the planet. Users can rotate the visualizations to view atmospheric gravity waves from different angles.<\/p>\n
Launched on Nov. 9, 2023, AWE is managed by the Explorers Program Office at NASA\u2019s Goddard Space Flight Center in Greenbelt, Maryland. Utah State University\u2019s Space Dynamics Laboratory built the AWE instrument and provided the mission operations center.<\/p>\n
Hear more about AWE by listening to episode 334 of NASA\u2019s Houston We Have a Podcast, recorded on Jan. 26, 2024.<\/p>\n