Abstract
Connections between the spring Antarctic Oscillation (AAO) and the East Asian summer monsoon (EASM) in two reanalysis datasets—NCEP-1 (NCEP/NCAR Reanalysis 1) and ERA-40 (ECMWF 40-year Reanalysis)—are investigated in this study. Both show significant correlation between AAO and EASM rainfall over the Yangtze River valley, especially after about 1985. Though ERA-40 shows weaker anomalous signals connecting AAO and EASM over southern high latitudes than NCEP-1, both datasets reveal similar connecting patterns between them. A wave-train-like pattern appears in the upper levels, from southern high latitudes through east of Australia and from the Maritime Continent to East Asia. In positive AAO years, the cross equatorial southeasterly flow over the Maritime Continent in the lower levels is strengthened, the specific humidity of the whole atmosphere over East Asia increases, and convective activity is enhanced; thus the summer rainfall over East Asia increases. The spring AAO-EASM connection may be better represented in ERA-40.
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Annamalai, H., J. M. Slingo, K. R. Sperber, and K. Hodges, 1999: The mean evolution and variability of the Asian summer monsoon: Comparison of ECMWF and NCEP-NCAR reanalyses. Mon. Wea. Rev., 127, 1157–1186.
Fan, K., and H. J. Wang, 2004: Antarctic oscillation and the dust weather frequency in North China. Geophys. Res. Lett., 31, L10201.
Fan, K., and H. J. Wang, 2006: Interannual variability of Antarctic Oscillation and its influence on East Asian climate during boreal winter and spring. Science in China(D), 49(5), 554–560.
Gong, D. Y., and S.W. Wang, 1999: Definition of Antarctic Oscillation Index. Geophys. Res. Lett., 26, 459–462.
Huang, R. H., and F. Y. Sun, 1994: The impact of thermal state in the western Pacific warm pool and the convective activity above the warm pool on the East Asian climate anomalies. Chinese J. Atmos. Sci., 18, 141–151. (in Chinese)
Kalnay, E., and Coauthors, 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc., 77, 437–471.
Krishnamurti, T. N., 1979: Tropical meteorology. Compendium of Meteorology, A. Wan-Nielsen, Ed., WMO No. 364, 428pp.
Marshall, G. J., 2003: Trends in the Southern annular mode from observations and reanalyses. J. Climate. 16, 4134–4143.
Nan, S. L., and J. P. Li, 2003: The relationship between the summer precipitation in the Yangtze River valley and the boreal spring Southern Hemisphere annular mode. Geophys. Res. Lett., 30, 2266.
Nitta, T., 1987: Convective activities in the tropical western Pacific and their impact on the northern hemisphere summer circulation. J. Meteor. Soc. Japan, 65, 373–390.
Pawson, S., and M. Fiorino, 1998: A comparison of reanalyses in the tropical stratosphere. Part 2: The quasi-biennial oscillation. Climate Dyn., 14, 645–658.
Sterl, A., 2004: On the (in) homogeneity of reanalysis products. J. Climate, 17, 3866–3873.
Sun, J. Q., H. J. Wang, and W. Yuan, 2008: A possible mechanism for the co-variability of the boreal spring Antarctic Oscillation and the Yangtze River valley summer rainfall. International Journal of Climatology, doi: 10.1002/joc.1773.
Sun, S. Q., and S. J. Ma, 2001: Anomalies of the western Pacific subtropical high and its relation to the flood in Yangtze River Valley in 1998. Acta Meteorologica Sinica, 59, 719–729. (in Chinese)
Tao, S. Y., and L. X. Chen, 1987: the East Asian summer. Review in Monsoon Meteorology., Oxford University Press, 60–92.
Thompson, D. W. J., and J. M. Wallace, 2000: Annular modes in the extratropical circulation. Part I: Month-to-month variability. J. Climate, 13, 1000–1016.
Trenberth, K. E., D. P. Stepaniak, J. W. Hurrell, and M. Fiorino, 2001: Quality of reanalyses in the Tropics. J. Climate, 14, 1499–1510.
Uppala, S., and Coauthors, 2004: ERA-40: ECMWF 45-year reanalysis of the global atmosphere and surface conditions 1957–2002. ECMWF Newsletter Meteorology, 101, 2–21.
Wang, B., 2006: The Asian Monsoon. Springer, in association with Praxis Publishing, 268–279.
Wang, H. J., and K. Fan, 2005: Central-north China precipitation as reconstructed from the Qing dynasty: Signal of the Antarctic Atmospheric Oscillation. Geophys. Res. Lett., 32, L24705.
Wang, H. J., and K. Fan, 2007: Relationship between the Antarctic oscillation and the western North Pacific typhoon frequency. Chinese Science Bulletin, 52(4), 561–565.
Xue, F., H. J. Wang, and J. H. He, 2004: Interannual variability of Mascarene High and Australian High and their influences on East Asian summer monsoon. J. Meteor. Soc. Japan, 82, 1173–1186.
Xue, F., D. B. Jiang, X. M. Lang, and H. J. Wang, 2003: Influence of the Mascarene high and Australian high on the summer monsoon in East Asia: Ensemble simulation. Adv. Atmos. Sci., 20, 799–809.
Zhao, T. B., and C. B. Fu, 2006: Comparison of products from ERA-40, NCEP-2, and CRU with station data for summer precipitation over China. Adv. Atmos. Sci., 23, 593–604, doi: 10.1007/s00376-006-0593-1.
Zhao, T. B., W. D. Guo, and C. B. Fu, 2008: Calibrating and evaluating reanalysis surface temperature error by topographic correction. J. Climate, 21, 1440–1446.
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Zhu, Y. The Antarctic oscillation-East Asian summer monsoon connections in NCEP-1 and ERA-40. Adv. Atmos. Sci. 26, 707–716 (2009). https://doi.org/10.1007/s00376-009-8196-2
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DOI: https://doi.org/10.1007/s00376-009-8196-2