Articles | Volume 8
https://doi.org/10.5194/ars-8-231-2010
https://doi.org/10.5194/ars-8-231-2010
01 Oct 2010
 | 01 Oct 2010

Structural changes in lower ionosphere wind trends at midlatitudes

C. Jacobi, E. G. Merzlyakov, R. Q. Liu, T. V. Solovjova, and Y. I. Portnyagin

Abstract. Long-term variability of the mesosphere/lower thermosphere (lower E region ionosphere) since 1970 has been analyzed using wind data series obtained at Collm (52° N, 15° E) using the LF drift method and at Obninsk (55° N, 37° E) applying VHF meteor radar. Applying piecewise linear trend analysis with a priori unknown number and positions of breakpoints shows that trend models with breakpoints are generally to be preferred against straight lines. There is a strong indication for a change of trends in wind parameters around 1975–1980. Similar changes are also found in the lower atmosphere, e.g., in tropospheric temperatures. This indicates a coupling between atmospheric layers at time scales of decades.