How a NASA experiment will study ‘air glow’ to understand Space weather, why it matters

Subject : Science and Tech

Section: SPACE SECTOR

Context:

National Aeronautics and Space Administration (NASA) is set to launch the Atmospheric Waves Experiment (AWE) to study one of the important drivers of Space weather – the Earth’s weather.

What is Space weather and why is it important?

The term “space weather” refers to the variable conditions on the sun and in space that can influence the performance of the technology we use on Earth. Space weather can produce electromagnetic fields that induce extreme currents in wires, disrupting power lines, and even causing widespread power outages.
During certain days, when the weather over Earth turns rough or extreme, Space weather, too, can suffer extreme events. These have a direct impact on vital installations on Earth, like satellite-based communication, radio communication, and Space-based aircraft orbits or stations – affecting the smooth operations of the navigation and Global Positioning Systems (GPS) and power grids.
Apart from influences from the Sun-bound emissions, Space weather also comes under the impact of terrestrial weather.

What is a gravity wave?

In the atmosphere, there are a wide variety of waves, travelling both horizontally and vertically.
Atmospheric Gravity Waves (AWS) are one such kind of vertical wave. They are mostly generated when there is an extreme weather event or a sudden disturbance leading to a vertical displacement of stable air.
Natural phenomena like thunderstorms, hurricanes, tornadoes, regional orography and others have the potential to send out a variety of periodic waves, including AGWs, in the lower levels of the atmosphere.
When the atmosphere is stable, the temperature difference between the rising air and the atmosphere produces a force that pushes this air to its original position. The air will continuously rise and sink, thus creating a wave-like pattern.
AGW is a wave that moves through a stable layer of the atmosphere, wherein the upward-moving region is the most favourable for the formation of cloud patterns or streaks.
AGWs continue all the way to Space, where they contribute to the Space weather.

Atmospheric Waves Experiment (AWE):

It is a first-of-its-kindNASA experimental attempt aimed at studying the interactions between terrestrial and Space weather.
It is planned under NASA’s Heliophysics Explorers Program.
It will study the links between how waves in the lower layers of the atmosphere impact the upper atmosphere, and thus, Space weather.
It will be mounted on the exterior of the Earth-orbiting International Space Station (ISS). From the vantage point, it will look down at the Earth and record the colourful light bands, commonly known as airglow.
It will measure the airglow at mesopause (about 85 to 87 km above the Earth’s surface), where the atmospheric temperatures dip to minus 100 degrees Celsius.

What will AWE do?

Advanced Mesospheric Temperature Mapper (ATMT), an instrument onboard AWE will scan or map the mesopause. Using the four identical telescopes comprising an imaging radiometer, scientists hope to obtain the brightness of light at specific wavelengths.
This information can then be converted into a temperature map, which could reveal the airglow movement and give clues on their role in the upper atmosphere and Space weather.