Researchers have discovered the existence of hot atomic hydrogen atoms in an upper layer of earth’s atmosphere known as thermosphere.
The discovery changes current understanding of the distribution of hot atomic hydrogen and its interaction with other atmospheric constituents.
This discovery was enabled by development of new numerical techniques and their application to years worth of remote sensing measurements acquired by Nasa’s TIMED satellite. TIMED is Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite.
Atomic hydrogen scatters UV radiation emitted by the sun. The amount of scattered light depends on the amount of hydrogen atoms in the atmosphere
As an outcome, remote observations of the scattered H emission can be used to probe the abundance and spatial distribution of H.
To get information about upper atmosphere from such measurements, one needs to calculate exactly how the solar photons are scattered.
Researchers developed a model of the radiative transfer of the scattered emission.
This was performed along with a new analysis technique that incorporated a transition region between the lower and upper extents of the H distribution.
Temperature of the H atoms in the thermosphere was found to increase significantly with declining solar activity.
The finding is in contrast to the ambient atmospheric temperature, which decreases with declining solar activity.
Hot H atoms- Theorised to exist at very high attitudes.
- Now found as low as 250 km.
- Ongoing atmospheric escape of hydrogen caused Mars to lose water.
- H atoms play an important role in physics governing earth’s upper atmosphere.
- It serves as a shield for satellites in low earth orbit agains the harsh space environment.
