Statistical Analysis of Joule Heating and Thermosphere Response During Geomagnetic Storms of Different Magnitudes

Abstract

During a geomagnetic storm, the energy deposition from magnetosphere to thermosphere through Joule heating leads to variations in the total mass density of thermosphere. In this study, measurements obtained from the Challenging Minisatellite Payload and Gravity Recovery and Climate Experiment satellites between 2002 and 2008 are used to study the response of thermospheric density during geomagnetic storms of different magnitudes inferred from the Dst index. Based on the height‐integrated Joule heating with data derived from the Defense Meteorological Satellite Program spacecraft, we statistically analyze 265 geomagnetic storm cases to study the characteristics of Joule heating distribution and its influence on thermospheric density. The results show that between thermospheric density and Joule heating during weak and moderate geomagnetic storms, the time lag is only about 0–2 hr, while the same for intense storms is 3–5 hr. This indicates that the time lag is positively correlated with the intensity of geomagnetic storms. Besides, it is found that the peak duration of Joule heating increases for more intense geomagnetic storms.

The Relationship Between Large Scale Thermospheric Density Enhancements and the Spatial Distribution of Poynting Flux

“…For example, the cusp peak of Δρ is approximately the same when B z is both positive and negative (with zero B y ), but the Poynting flux is larger by around a factor of two when the IMF is southward compared to northward. This might be because a short term (10s of minutes) injection of downward Poynting flux near the cusp would result in the neutral density in the same region to become enhanced for several hours (e.g., Sutton et al, 2009;Wang et al, 2020). The discrepancy between how short a time the Poynting flux is enhanced and how long the neutral mass density is enhanced would cause the patterns of Δρ to be biased towards strong geomagnetic events, whilst S ‖ would be biased towards quiet geomagnetic times which are more frequent than large events such as those seen by Crowley et al (2010) and Knipp et al (2011).…”

Latitudinal Impacts of Joule Heating on the High‐Latitude Thermospheric Density Enhancement During Geomagnetic Storms

“…When the orbits from the three satellites have overlapped with each other, the averaged density is used for the grid with 0.25° × 0.25°. Such interpolation method has been used to study in the previous work (Wang, Miao, Aa, et al., 2020). We acquire the Joule heating from the methods introduced in Section 2, and calculate the 3‐h average for Joule heating distribution corresponding to per 3 h thermospheric density.…”

“…The Joule heating is calculated as discussed in Wang, Miao, Aa, et al. (2020). We use height‐integrated Pederson conductance () and the electric field ( E ) to examine the distribution of height‐integrated Joule heating () and follow the outlined approach: The Pederson conductance is mainly controlled by the solar radiation and particle precipitation.…”

Using Temporal Relationship of Thermospheric Density With Geomagnetic Activity Indices and Joule Heating as Calibration for NRLMSISE‐00 During Geomagnetic Storms

“…The thermospheric response can be variable with different magnitudes of geomagnetic storms (Wang, Miao, Aa, et al., 2020; Zesta & Oliveira, 2019). In this study, 265 geomagnetic storms are statistically analyzed from 2002 to 2008, and storm levels are classified by the minimum Dst values during storms (Gonzalez et al., 1999; Srivastava & Venkatakrishnan, 2004).…”

“…Due to the variance of altitudinal energy deposition, Wang, Miao, Aa, et al. (2020) discovered that thermospheric density delays Joule heating for a longer time as geomagnetic storms intensify. Therefore, the response times of neutral mass densities to Dst indices, AE indices, and Joule heating is of paramount significance to study thermospheric density enhancements during geomagnetic storms.…”