A. Bartzokas et Da. Metaxas, COVARIABILITY AND CLIMATIC CHANGES OF THE LOWER-TROPOSPHERE TEMPERATURES OVER THE NORTHERN-HEMISPHERE, Nuovo cimento della Societa italiana di fisica. C, Geophysics and space physics, 16(4), 1993, pp. 359-373
The covariability and the long-term fluctuation of the lower-troposphe
re temperatures is studied, applying factor analysis on grid point (10
00 divided by 500) hPa thickness data for the Northern Hemisphere. Abo
ut 30 factors were retained and rotated for each season and year, but
only about half of them were found to be significant. The grouping of
the grid points according to the factor loadings has been mainly influ
enced by the land and sea distribution. Three teleconnections were fou
nd only, one in winter and two in summer. The winter one is a see-saw
phenomenon between West Asia and North-West Scandinavia. In summer, th
e British Isles were found to covary with East Canada and the same is
the case for almost all the subtropical deserts. The study of the fact
or scores revealed that the recent warming of the Earth's surface in t
he lower troposphere appears over the continents only.