Advances in Atmospheric Sciences

, 26:1209

Enhancement of the summer North Atlantic Oscillation influence on Northern Hemisphere air temperature

Authors

    • China Meteorological Administration Training Centre
  • Jianqi Sun孙建奇
    • Institute of Atmospheric PhysicsChinese Academy of Sciences
Article

DOI: 10.1007/s00376-009-8148-x

Cite this article as:
Yuan, W. & Sun, J. Adv. Atmos. Sci. (2009) 26: 1209. doi:10.1007/s00376-009-8148-x

Abstract

This study investigates the relationship between the summer North Atlantic Oscillation (SNAO) and the simultaneous Northern Hemisphere (NH) land surface air temperature (SAT) by using the Climate Research Unit (CRU) data. The results show that the SNAO is related to NH land SAT, but this linkage has varied on decadal timescales over the last 52 years, with a strong connection appearing after the late 1970s, but a weak connection before. The mechanism governing the relationship between the SNAO and NH land SAT is discussed based on the NCEP/NCAR reanalysis data. The results indicate that such a variable relationship may result from changes of the SNAO mode around the late 1970s. The SNAO pattern was centered mainly over the North Atlantic before the late 1970s, and thus had a weak influence on the NH land SAT. But after the late 1970s, the SNAO pattern shifted eastward and its southern center was enhanced in magnitude and extent, which transported the SNAO signal to the North Atlantic surrounding continents and even to central East Asia via an upper level wave train along the Asian jet.

Key words

Summer North Atlantic Oscillationsurface air temperaturewave train

Copyright information

© Chinese National Committee for International Association of Meteorology and Atmospheric Sciences, Institute of Atmospheric Physics, Science Press and Springer Berlin Heidelberg 2009