HD 81809 has one of the highest-quality activity cycles from the sample of stars synoptically observed in the Mount Wilson Observatory HK Project.
HD 81809 has one of the highest-quality activity cycles from the sample of stars synoptically observed in the Mount Wilson Observatory HK Project.
Peterson et al. (2015) developed an algorithm for estimating the electric field vector at any point above an electrified cloud from passive microwave observations.
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.