Preliminary Investigation of the Effects of Major Geomagnetic Storms on Mesosphere and Lower Thermosphere (MLT) Region Temperatures over Arecibo

Geomagnetic storms are known for their wide range of impacts on the Earth’s magnetosphere, satellites, power grid, and astronauts. A majority of these storms are caused by coronal mass ejections (CMEs) which are massive solar explosions containing high-energy particles embedded with magnetic fields. When directed toward Earth, CMEs can significantly disrupt Earth’s magnetic field and initiate particle precipitation and heating at high latitudes. This induces significant temperature changes in the upper atmosphere at high to mid-latitudes (e.g., Krassovsky 1968, Richmond & Lu 2000, Yuan et al. 2015, Liu et al. 2018). The mesosphere-lower thermosphere (MLT) region plays an important role in the transfer of energy and momentum between the lower-middle atmosphere and the upper atmosphere. Therefore, it is important to determine how much geomagnetic storms influence this dynamic region. On the contrary to the upper atmosphere, there are only a few studies on the effects of severe geomagnetic storms in the MLT region. Most of them have been carried out from the high or mid-latitudes while such studies are sparse in the low-latitude region. In this study, temperature perturbation in the MLT region in the Earth’s atmosphere over Arecibo (18° N latitude) during major geomagnetic storms is investigated. Rotational temperature data obtained with the Arecibo Observatory (AO) Ebert-Fastie spectrometer is utilized in this work. The results obtained from our analysis will be discussed in the presentation. To our knowledge, such a study has not been carried out previously by using Arecibo Observatory MLT temperature data.