Intercomparison of the temperature contrast between the arctic and equator in the pre- and post periods of the 1976/1977 regime shift
- 199 Downloads
Based on the National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) reanalysis temperature dataset in the period of 1948–2014, the temperature contrast between the Arctic and equator in the pre- and post periods of the 1976/1977 regime shift is compared. An index measuring the temperature contrast is defined as the difference between the Arctic zone (70° N–90° N) and the equatorial region (10° S–10° N). The variations of the temperature contrast can be mainly explained by the local sea ice variations through sea ice–albedo–temperature feedback before 1976/1977 and the energy transportation to the Arctic together with the local sea ice after 1976/1977. The impacts of the Arctic minus equator (AmE) temperature contrast on the high-level westerly jet, and the polar easterlies show a significant difference during the two periods. A strong temperature anomaly associated with the temperature contrast in the two periods is found in the high latitude, but different patterns are observed at the high and low levels. The correlated water vapor appeared in the Indian Ocean and Maritime Continent before 1976/1977 and moved to northeastern Canada and eastern North America after 1976/1977.
KeywordsRegime Shift Temperature Contrast Arctic Zone Arctic Warming Ferrel Cell
The authors would like to thank the agencies for providing the data sets including the NOAA/CDC website and the Hadley Centre website. Constructive comments from anonymous reviewers and Dr. Hartmut Graßl helped to improve this manuscript. The first author is partially supported by the National Natural Science Foundation (41105056, 41330425) and supported under the State Scholarship Fund (201308320043).
- IPCC (2007) In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL(eds) Climate change 2007: the physical science basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, CambridgeGoogle Scholar
- Nitta T, Yamada S (1989) Recent warming of tropical sea surface temperature and is relationship to the northern hemisphere circulation. J Meteorol Soc Japan 67:375–383Google Scholar