Characteristics of equatorial morning overshoot observed by the Swarm constellation
Abstract
In this paper we investigate the altitudinal and longitudinal variations of electron temperature at equatorial latitudes and compare our results with other observations. The rapid increase of electron temperature in the early morning period at the low-latitude and equatorial region is well known ionospheric phenomenon called the morning overshoot. Electron temperature and density data used in this study were obtained from the Langmuir probe on board the Swarm constellation which is in near polar orbit at two different altitudes of 470 km and 520 km with three identical satellites. Based on the data set between 2013 and 2019, we studied the electron temperature and density in terms of local time, season, latitude, longitude, and magnetic activity. To see the altitudinal difference of electron temperature and density, we also use the data from Floating Potential Measurement Unit (FPMU) on board International Space Station which is in low-earth orbit at an altitude of 400 km. We confirm the morning overshoot, where electron temperature has a maximum at the dip latitude and decreases gradually with increasing latitude in all seasons. But the amplitude of morning overshoot electron temperature is not uniform over season and longitude. Lastly, the response of ionospheric electron temperature to geomagnetic activity shows anticorrelation.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSA51B3139Y
- Keywords:
-
- 2415 Equatorial ionosphere;
- IONOSPHERE;
- 2431 Ionosphere/magnetosphere interactions;
- IONOSPHERE;
- 6969 Remote sensing;
- RADIO SCIENCE;
- 7944 Ionospheric effects on radio waves;
- SPACE WEATHER