Solar cycle dependence and long-term trends in the wind field of the mesosphere lower thermosphere

Ground-based observations of the wind field in the mesosphere/lower thermosphere have been used to investigate long-lasting wind variations at mid-latitudes. Besides small solar activity induced variations (11 yr cycle), non-solar induced long-term trends were clearly detected, which could be a hint of anthropogenically caused variations in the wind field near the mesopause region. Comparisons with other observations qualitatively confirm the derived trends, thus indicating common long-term global changes of the dynamical state of the middle atmosphere. (C) 1997 Elsevier Science Ltd.