Tropospheric temperature anomalies in the Northern Hemisphere 1977–1986

• Published in: International Journal of Climatology
• Main Author: Weber, Gerd‐Rainer
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1990
• Subjects: Arctic; Pacific
• Online Access: http://dx.doi.org/10.1002/joc.3370100103; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjoc.3370100103; https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/joc.3370100103

Abstract Tropospheric temperatures for the Northern Hemisphere (NH) during the period 1977–1986 are analysed on the basis of 300/1000 mbar thickness data between latitudes 10 °N and 80 °N. The departures from the mean 1951–1960 are determined on a 10 ° by 10° grid. Averages and trends are calculated for latitude circles for the entire NH, separately for oceanic and continental areas, as well as for specific geographic regions. An attempt is made to find relationships between the anomaly patterns by means of teleconnections. It is found that in the 10–year period the tropical and subtropical troposphere was considerably warmer than during the reference period and that this positive anomaly was particularly prominent over the tropical and subtropical Pacific. The northern Pacific, the northern Atlantic, and the European‐Canadian sector of the Arctic showed coincident negative anomalies. The resulting increase in subtropical to mid‐latitude tropospheric temperature gradient over both oceans was calculated to be more than 1 K, indicating an intensified circulation during the period. Using teleconnections for various latitude and longitude sectors it can be shown that the NH anomaly pattern 1977–1986 is strongly influenced by variations in the thickness pattern over the subtropical Pacific along latitude circle 20°N. The strongest relations emerge between the subtropical Pacific and western North America, the East Atlantic, and central Asia, where over 60 per cent of the variances in thickness can be explained by thickness variations over the subtropical Pacific.