Phys.org June 7, 2024
The dynamics of upper atmosphere winds differ significantly from those at lower altitudes, with larger magnitudes and increased sensitivity to solar events. An international team of researchers (Germany, Japan) used multi-year observations of cross-track winds (u) from the CHAllenging Minisatellite Payload (CHAMP) and the Gravity Field and Steady State Ocean Circulation Explorer (GOCE) to calculate third-order structure functions in the thermosphere as a function of horizontal separation (s). They presented two main characteristics – they are consistently positive, predicting a preferential cyclonic rotational motion (counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere) and, the functions display the same type of dependence on the horizontal distance as third-order SFs of winds in the lower atmosphere. This suggested that similar underlying large-scale turbulence mechanisms may be at play… read more. Open Access TECHNICAL ARTICLEÂ
Map showing CHAMP and GOCE orbit paths as green and orange dots, respectively. Credit: Geophysical Research Letters, 03 June 2024