The extension of the neutral atomic Na layer into thermosphere (up to 170 km) was observed in low and high latitudes.
The extension of the neutral atomic Na layer into thermosphere (up to 170 km) was observed in low and high latitudes.
The Interface Region Imaging Spectrograph (IRIS) is a NASA Small Explorer mission that provides high-resolution spectra and images of the Sun in the 133–141 nm and 278–283 nm wavelength bands.
Observations from lidars and satellites have shown that large temperature increases and decreases occur in the middle and low latitudes of the mesosphere and lower thermosphere (MLT) region during geomagnetic storms.
Periodic oscillations associated with Alfven waves with periods ranging from several tens of minutes to several hours are commonly seen in the solar wind.
The Sun occasionally goes through Maunder-like extended grand minima when its magnetic activity drops considerably from the normal activity level for several decades. Many possible theories have been proposed to explain the origin of these minima.