  The results of an analysis of temperature variations in the mesopause region
based on long-term measurements of hydroxyl airglow at the Zvenigorod
Scientific Station of the A.M. Obukhov Institute of Atmospheric Physics RAS
(ZSS IAP RAS) in 1960-2024 in comparison with variations of surface temperature
characterizing global-scale climate changes are presented. Along with
temperature variations in the mesopause region, two versions of temperature
variations in the mesopause region, normalized to the same level of solar
activity, were analyzed. Quantitative estimates of a strong decrease in
temperature in the mesopause region over the past decades in winter against the
background of a global increase in surface temperature have been obtained. It
was noted that significant coherence of long-term variations for temperature in
the mesopause region with the surface temperature in the Northern Hemisphere
with the use of cross-wavelet analysis, what was not previously evident in data
for a shorter time interval. The possibility of such coherence was predicted in
(Mokhov et al., 2017) under the continuation of global warming based on the
results of model simulations for the 20-21 centuries, taking into account
anthropogenic forcing. It was not previously manifested from observational data
for a shorter time interval. Along with long-term trends, features of a sharp
decrease in temperature in the mesopause region in the 1970s with its
synchronicity with the known shift in surface climate regimes associated with
El Ni\~no events were analyzed. The results of cross-wavelet analysis using
data obtained at the ZSS IAP RAS for the time interval 1960-2024 indicate a
more significant connection between temperature variations in the mesopause
region and El Nino indices in recent decades.
