Long term solar variability and effects on the mesosphere and thermosphere
| Autor: | Mlynczak, M., Hunt, L. |
|---|---|
| Rok vydání: | 2023 |
| Zdroj: | XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
| DOI: | 10.57757/iugg23-0175 |
| Popis: | We examine variability in the thermal structure and energetics of the mesosphere and thermosphere using the existing Thermosphere Climate Index (TCI) and the new Mesosphere Climate Index (MCI). These indexes are constructed from the F10.7 solar radio flux index and the Ap index based on SABER observations of radiative cooling by thermospheric nitric oxide (TCI) and of the temperature and thickness of the mesosphere (MCI). The indexes date from 1947 to the present. Comparisons between the emerging solar cycle 25 and the past seven solar cycles are considered. The mesosphere is shown to have cooled substantially over this time period, consistent with traditional trend calculations over shorter timescales. The TCI indicates that solar activity in the current cycle is nearly equivalent with the peak activity of solar cycle 24 as of late January 2023. Long and short term periodic features in the data are also shown, in particular, a recurring 6-month periodicity in the TCI during the most recent solar minimum period. The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) |
| Databáze: | OpenAIRE |
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