• Annamalai, H., and J. M. Slingo, 2001: Active/break cycles: Diagnosis of the intraseasonal variability of the Asian Summer Monsoon. Climate Dyn., 18 , 85102.

    • Search Google Scholar
    • Export Citation
  • Bingham, C., M. D. Godfrey, and J. W. Tukey, 1967: Modern techniques of power spectrum estimation. IEEE Trans. Audio Electroacoust., AU-15 , 5666.

    • Search Google Scholar
    • Export Citation
  • Chao, J. M., 1991: The characteristics of the quasi-two week oscillation of isobaric surface geopotential height over China and its relationships with the summer monsoon strength and the rainfall over the northern China from July to August (in Chinese). Acta Geogr. Sin., 4 , 2330.

    • Search Google Scholar
    • Export Citation
  • Chen, T. C., and M. Murakami, 1988: The 30–50 day variation of convective activity over the western Pacific Ocean with emphasis on the northwestern region. Mon. Wea. Rev., 116 , 892906.

    • Search Google Scholar
    • Export Citation
  • Chen, T. C., and J. R. Chen, 1995: An observational study of the South China Sea monsoon during the 1979 summer: Onset and life cycle. Mon. Wea. Rev., 123 , 22952318.

    • Search Google Scholar
    • Export Citation
  • Chen, T. C., M. C. Yen, and S. P. Weng, 2000: Interaction between the summer monsoons in East Asia and the South China Sea: Intraseasonal monsoon modes. J. Atmos. Sci., 57 , 13731392.

    • Search Google Scholar
    • Export Citation
  • Chen, W. Y., 1982: Fluctuations in Northern Hemisphere 700 mb height field associated with Southern Oscillation. Mon. Wea. Rev., 110 , 808883.

    • Search Google Scholar
    • Export Citation
  • Ding, Q., and B. Wang, 2007: Intraseasonal teleconnection between the Eurasian wave train and Indian monsoon. J. Climate, 20 , 37513767.

    • Search Google Scholar
    • Export Citation
  • Ding, Y. H., 1992: Summer monsoon rainfall in China. J. Meteor. Soc. Japan, 70 , 373396.

  • Fujinami, H., and T. Yasunari, 2004: Submonthly variability of convection and circulation over and around the Tibetan Plateau during the boreal summer. J. Meteor. Soc. Japan, 82 , 15451564.

    • Search Google Scholar
    • Export Citation
  • Gilman, D. L., F. J. Fuglister, and J. M. Mitchell Jr., 1963: On the power spectrum of red noise. J. Atmos. Sci., 20 , 182184.

  • Hsu, H. H., and C. H. Weng, 2001: Northwestward propagation of the intraseasonal oscillation in the western North Pacific during the boreal summer: Structure and mechanism. J. Climate, 14 , 38343850.

    • Search Google Scholar
    • Export Citation
  • Hsu, H. H., C-H. Weng, and C-H. Wu, 2004: Contrasting characteristics between the northward and eastward propagation of the intraseasonal oscillation during the boreal summer. J. Climate, 17 , 727743.

    • Search Google Scholar
    • Export Citation
  • Kajikawa, Y., and T. Yasunari, 2005: Interannual variability of the 10–25- and 30–60-day variation over the South China Sea during boreal summer. Geophys. Res. Lett., 32 , L04710. doi:10.1029/2004GL021836.

    • Search Google Scholar
    • Export Citation
  • Kanamitsu, M., W. Ebisuzaki, J. Woollen, S. K. Yang, J. J. Hnilo, M. Fiorino, and G. L. Potter, 2002: NCEP-DOE AMPI-II Reanalysis (R-2). Bull. Amer. Meteor. Soc., 83 , 16311643.

    • Search Google Scholar
    • Export Citation
  • Kang, I. S., C. H. Ho, Y. K. Lim, and K. M. Lau, 1999: Principal modes of climatological seasonal and intraseasonal variations of the Asian summer monsoon. Mon. Wea. Rev., 127 , 322340.

    • Search Google Scholar
    • Export Citation
  • Kemball-Cook, S., and B. Wang, 2001: Equatorial waves and air–sea interaction in the boreal summer intraseasonal oscillation. J. Climate, 14 , 29232942.

    • Search Google Scholar
    • Export Citation
  • Kikuchi, K., and B. Wang, 2009: Global perspectives of the quasi-biweekly oscillation. J. Climate, 22 , 13401359.

  • Krishnamurti, T. N., and H. N. Bhalme, 1976: Oscillations of a monsoon system. Part I: Observational aspects. J. Atmos. Sci., 33 , 19371954.

    • Search Google Scholar
    • Export Citation
  • Krishnamurti, T. N., and P. Ardanuy, 1980: The 10 to 20 day westward propagating modes and breaks in the monsoons. Tellus, 32 , 1526.

  • Krishnamurti, T. N., and D. Subrahmanyam, 1982: The 30-50 day mode at 850 mb during MONEX. J. Atmos. Sci., 39 , 20882095.

  • Lau, K-M., G. J. Yang, and S. H. Shen, 1988: Seasonal and intraseasonal climatology of summer monsoon rain over East Asia. Mon. Wea. Rev., 116 , 1837.

    • Search Google Scholar
    • Export Citation
  • Lawrence, D. M., and P. J. Webster, 2002: The boreal summer intraseasonal oscillation: Relationship between northward and eastward movement of convection. J. Atmos. Sci., 59 , 15931606.

    • Search Google Scholar
    • Export Citation
  • Liebmann, B., and C. A. Smith, 1996: Description of a complete (interpolated) outgoing longwave radiation dataset. Bull. Amer. Meteor. Soc., 77 , 12751277.

    • Search Google Scholar
    • Export Citation
  • LinHo, and B. Wang, 2002: The time-space structure of the Asian-Pacific summer monsoon: A fast annual cycle view. J. Climate, 15 , 20012019.

    • Search Google Scholar
    • Export Citation
  • Liu, H., D-L. Zhang, and B. Wang, 2008: Daily to submonthly weather and climate characteristics of the summer 1998 extreme rainfall over the Yangtze River Basin. J. Geophys. Res., 113 , D22101. doi:10.1029/2008JD010072.

    • Search Google Scholar
    • Export Citation
  • Liu, J., B. Wang, and J. Yang, 2008: Forced and internal modes of variability of the East Asian summer monsoon. Climate Past, 4 , 19.

  • Livezey, R. E., and W-Y. Chen, 1983: Statistical field significance and its determination by Monte Carlo techniques. Mon. Wea. Rev., 111 , 4659.

    • Search Google Scholar
    • Export Citation
  • Mao, J. Y., and J. C. L. Chan, 2005: Intraseasonal variability of the South China Sea summer monsoon. J. Climate, 18 , 23882402.

  • Mao, J. Y., and G. X. Wu, 2006: Intraseasonal variations of the Yangtze rainfall and its related atmospheric circulation features during the 1991 summer. Climate Dyn., 27 , 815830.

    • Search Google Scholar
    • Export Citation
  • Murakami, T., 1980: Empirical orthogonal function analysis of satellite-observed outgoing longwave radiation during summer. Mon. Wea. Rev., 108 , 205222.

    • Search Google Scholar
    • Export Citation
  • Nakazawa, T., 1992: Seasonal phase lock of intraseasonal variation during the Asian summer monsoon. J. Meteor. Soc. Japan, 70 , 597611.

    • Search Google Scholar
    • Export Citation
  • Onogi, K., and Coauthors, 2007: The JRA-25 Reanalysis. J. Meteor. Soc. Japan, 85 , 369432.

  • Simmons, A. J., J. M. Wallace, and G. W. Branstator, 1983: Barotropic wave propagation and instability, and atmospheric teleconnection patterns. J. Atmos. Sci., 40 , 13631392.

    • Search Google Scholar
    • Export Citation
  • Tao, S-Y., and L. S. Chen, 1987: A review of recent research on the East Asian summer monsoon in China. Monsoon Meteorology, C. P. Chang and T. N. Krishnamurti, Eds., Oxford University Press, 60–92.

    • Search Google Scholar
    • Export Citation
  • Tao, S-Y., Q. Zhang, and S. Zhang, 2001: An observational study on the behavior of the subtropical high over the west Pacific in summer. Acta Meteor. Sin., 59 , 748758.

    • Search Google Scholar
    • Export Citation
  • Uppala, S. M., and Coauthors, 2005: The ERA-40 Re-Analysis. Quart. J. Roy. Meteor. Soc., 131 , 29613012.

  • Wang, B., and X. H. Xu, 1997: Northern Hemisphere summer monsoon singularities and climatological intraseasonal oscillation. J. Climate, 10 , 10711085.

    • Search Google Scholar
    • Export Citation
  • Wang, Y., O. L. Sen, and B. Wang, 2003: A highly resolved regional climate model (IPRC RegCM) and its simulation of the 1998 severe precipitation event over China. Part I: Model description and verification of simulation. J. Climate, 16 , 17211738.

    • Search Google Scholar
    • Export Citation
  • Wilks, D. S., 1995: Statistical Methods in the Atmospheric Sciences: An Introduction. Academic Press, 467 pp.

  • Xie, P., A. Yatagai, M. Chen, T. Hayasaka, Y. Fukushima, C. Liu, and S. Yang, 2007: A gauge-based analysis of daily precipitation over East Asia. J. Hydrometeor., 8 , 607627.

    • Search Google Scholar
    • Export Citation
  • Yang, J., 2008: Climatological and transient intraseasonal oscillations in the East-Asia-Western North Pacific summer monsoon. Ph.D. dissertation, Insititute of Atmospheric Physics, Chinese Academy of Sciences, 106 pp.

  • Yang, J., B. Wang, and B. Wang, 2008: Anticorrelated intensity change of the quasi-biweekly and 30–50-day oscillations over the South China Sea. Geophys. Res. Lett., 35 , L16702. doi:10.1029/2008GL034449.

    • Search Google Scholar
    • Export Citation
  • Yatagai, A., P. Xie, and P. Alpert, 2008: Development of a daily gridded precipitation data set for the Middle East. Adv. Geosci., 12 , 165170.

    • Search Google Scholar
    • Export Citation
  • Zhang, Q. Y., S. Y. Tao, and S. L. Zhang, 2003: The persistent heavy rainfall over the Yangtze River valley and its associations with the circulations over East Asia during summer (in Chinese). Chinese J. Atmos. Sci., 27 , 10181030.

    • Search Google Scholar
    • Export Citation
  • Zhang, X. L., P. W. Guo, and J. H. He, 2002: Characteristics of low frequency oscillation of precipitation and wind field in the middle and low reaches of the Yangtze River in summer 1991 (in Chinese). J. Nanjing Inst. Meteor., 25 , 388394.

    • Search Google Scholar
    • Export Citation
  • Zhu, C. W., T. Nakazawa, J. Li, and L. Chen, 2003: The 30–60 day intraseasonal oscillation over the western North Pacific Ocean and its impacts on summer flooding in China during 1998. Geophys. Res. Lett., 30 , 1952. doi:10.1029/2003GL017817.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 23 23 23
PDF Downloads 11 11 11

Biweekly and 21–30-Day Variations of the Subtropical Summer Monsoon Rainfall over the Lower Reach of the Yangtze River Basin

View More View Less
  • 1 State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, and State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
  • | 2 Department of Meteorology, and International Pacific Research Center, University of Hawaii at Manoa, Honolulu, Hawaii, and College of Physical Oceanography and Marine Environment, Ocean University of China, Qingdao, China
  • | 3 State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
Restricted access

Abstract

The lower reach of the Yangtze River basin (LYRB) is located at the central region of the mei-yu and baiu front, which represents the subtropical East Asian (EA) summer monsoon. Based on the newly released daily rainfall data, two dominant intraseasonal variation (ISV) modes are identified over the LYRB during boreal summer (May–August), with spectral peaks occurring on day 15 (the biweekly mode) and day 24 (the 21–30-day mode). These two modes have comparable intensities, and together they account for above about 57% of the total intraseasonal variance. Both ISV modes exhibit baroclinic structures over the LYRB at their extreme phases.

However, the genesis and evolutions associated with the two modes are different. Considering the genesis of their extreme wet phases over the LYRB, the biweekly mode is initiated by a midlatitude jet stream vorticity anomaly moving southeastward, while the 21–30-day mode is primarily associated with a low-level westward propagation of an anticyclonic anomaly from 145° to 120°E, which reflects the westward extension of the western North Pacific subtropical high (WNPSH). The development of the biweekly mode at LYRB is enhanced by the northwestward movement of a low-level anticyclonic anomaly from the Philippine Sea to the south of Taiwan, which is a result of the enhancement of the WNPSH resulting from its merger with a transient midlatitude high. In contrast, the development of the 21–30-day mode is enhanced by an upper-level trough anomaly moving from Lake Baikal to far east Russia. These two ISV periodicities are also found to be embedded in their corresponding source regions.

The new knowledge on the sources and evolutions of the two major LYRB ISV modes provides empirical predictors for the intraseasonal variation in the subtropical EA summer monsoon.

Corresponding author address: Dr. Jing Yang, State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China. Email: yangjing@bnu.edu.cn

Abstract

The lower reach of the Yangtze River basin (LYRB) is located at the central region of the mei-yu and baiu front, which represents the subtropical East Asian (EA) summer monsoon. Based on the newly released daily rainfall data, two dominant intraseasonal variation (ISV) modes are identified over the LYRB during boreal summer (May–August), with spectral peaks occurring on day 15 (the biweekly mode) and day 24 (the 21–30-day mode). These two modes have comparable intensities, and together they account for above about 57% of the total intraseasonal variance. Both ISV modes exhibit baroclinic structures over the LYRB at their extreme phases.

However, the genesis and evolutions associated with the two modes are different. Considering the genesis of their extreme wet phases over the LYRB, the biweekly mode is initiated by a midlatitude jet stream vorticity anomaly moving southeastward, while the 21–30-day mode is primarily associated with a low-level westward propagation of an anticyclonic anomaly from 145° to 120°E, which reflects the westward extension of the western North Pacific subtropical high (WNPSH). The development of the biweekly mode at LYRB is enhanced by the northwestward movement of a low-level anticyclonic anomaly from the Philippine Sea to the south of Taiwan, which is a result of the enhancement of the WNPSH resulting from its merger with a transient midlatitude high. In contrast, the development of the 21–30-day mode is enhanced by an upper-level trough anomaly moving from Lake Baikal to far east Russia. These two ISV periodicities are also found to be embedded in their corresponding source regions.

The new knowledge on the sources and evolutions of the two major LYRB ISV modes provides empirical predictors for the intraseasonal variation in the subtropical EA summer monsoon.

Corresponding author address: Dr. Jing Yang, State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China. Email: yangjing@bnu.edu.cn

Save