Abstract
Two ∼2-week Ultra-Fast Kelvin Wave (UFKW) events centered on days 158(203) during 2021 are investigated using winds, temperatures, plasma drifts and electron densities (Ne) measured by the Ionospheric CONnections (ICON) mission. Eastward-propagating longitudinal wave-1 (s = −1) structures with periods 2.5–4.0d, thought to mainly reflect Ultra-Fast Kelvin waves (UFKWs), reveal ±45 ms−1 zonal winds (U) at 100 km for both events. Height-latitude structures of the 3.0(3.5)d-period UFKWs are obtained for the first time for both temperature (T, 94–120 km) and U (94–280 km) between 12°S and 39°N latitude. Maximum values of 36(29) ms−1 for U and 12(15)K for T occur at 102(106) km altitude and within ±3° latitude. The U-T peak height displacement remains unexplained. Vertical wavelengths are in the range 36–43 km for both U and T during both events. Concurrent with the E-region dynamo winds, topside (580 km) F-region field-aligned (±20–40 ms−1), meridional (±5–10 ms−1) and vertical (±5–10 ms−1) drift and Ne (±20–40%) 2.5–4.0d s = −1 variations are also measured. These key elements of atmosphere-ionosphere (A-I) coupling, contemporaneously measured for the first time, are relevant to testing the internal consistency of A-I models. The mean wind propagation environment of the UFKWs is also quantified, showing no appreciable effects on the UFKW structures, consistent with modeling and theory.
Original language | English (US) |
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Article number | e2023GL105975 |
Journal | Geophysical Research Letters |
Volume | 51 |
Issue number | 8 |
DOIs | |
State | Published - Apr 28 2024 |
Keywords
- ICON
- UFKW
- coupling
- ionosphere
- thermosphere
ASJC Scopus subject areas
- Geophysics
- General Earth and Planetary Sciences