We conduct observational and modeling studies of thermospheric composition responses to weak geomagnetic activity (non-geomagnetic storms). We found that the thermospheric O and N 2 column density ratio (∑O/N 2 ) in part of the Northern Hemisphere measured by

The National Aeronautics and Space Administration (NASA) Global‐scale Observations of the Limb and Disk (GOLD) has been imaging the thermosphere and ionosphere since October 2018. It provides continuous measurements over a large area from its geostationary orbit.

Thermospheric gravity waves in the bottomside F region have been proposed to play a key role in the generation of equatorial plasma bubbles (EPB). However, direct observations of such waves have been lacking.

Thermospheric gravity waves in the bottomside F region have been proposed to play a key role in the generation of equatorial plasma bubbles (EPB). However, direct observations of such waves have been lacking.

Over the past two decades mounting evidence demonstrated that terrestrial weather significantly influences the dynamics and mean state of the thermosphere.

Nitric oxide (NO) has long been recognized as one of the most important trace constituents in the middle and upper atmosphere.

Some recent studies have revealed that the post-storm thermospheric mass density sometime drops below its pre-storm value. This phenomenon has been attributed to the over-cooling effect caused by enhanced infrared emissions from nitric oxide.