The Effect of the MJO on the North American Monsoon

David J. Lorenz Department of Atmospheric Science, University of Washington, Seattle, Washington

Search for other papers by David J. Lorenz in
Current site
Google Scholar
PubMed
Close
and
Dennis L. Hartmann Department of Atmospheric Science, University of Washington, Seattle, Washington

Search for other papers by Dennis L. Hartmann in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

The effect of the Madden–Julian oscillation (MJO) in the eastern Pacific on the North American monsoon is documented using NCEP–NCAR reanalysis and daily mean precipitation data from 1958 to 2003. It is found that positive zonal wind anomalies in the eastern tropical Pacific lead to above-normal precipitation in northwest Mexico and Arizona from several days to over a week later. This connection between the tropical Pacific and monsoon precipitation appears to be limited to regions influenced by moisture surges from the Gulf of California as a similar connection does not exist for New Mexico precipitation. The evidence suggests that the MJO might affect monsoon precipitation by modulating the strength of low-level easterly waves off the coast of Mexico, which in turn triggers the development of a gulf surge.

* National Oceanic and Atmospheric Administration Contribution Number 1114

Corresponding author address: David J. Lorenz, Center for Climatic Research, Institute for Environmental Studies, University of Wisconsin—Madison, 1225 West Dayton St., Madison, WI 53706-1695. Email: dlorenz@wisc.edu

Abstract

The effect of the Madden–Julian oscillation (MJO) in the eastern Pacific on the North American monsoon is documented using NCEP–NCAR reanalysis and daily mean precipitation data from 1958 to 2003. It is found that positive zonal wind anomalies in the eastern tropical Pacific lead to above-normal precipitation in northwest Mexico and Arizona from several days to over a week later. This connection between the tropical Pacific and monsoon precipitation appears to be limited to regions influenced by moisture surges from the Gulf of California as a similar connection does not exist for New Mexico precipitation. The evidence suggests that the MJO might affect monsoon precipitation by modulating the strength of low-level easterly waves off the coast of Mexico, which in turn triggers the development of a gulf surge.

* National Oceanic and Atmospheric Administration Contribution Number 1114

Corresponding author address: David J. Lorenz, Center for Climatic Research, Institute for Environmental Studies, University of Wisconsin—Madison, 1225 West Dayton St., Madison, WI 53706-1695. Email: dlorenz@wisc.edu

Save
  • Adams, D. K., and A. C. Comrie, 1997: The North American monsoon. Bull. Amer. Meteor. Soc., 78 , 21972213.

  • Charba, J. P., A. W. Harrell III, and A. C. Lackner III, 1992: A monthly precipitation amount climatology derived from published atlas maps: Development of a digital database. TDL Office Note 92-7, National Weather Service, NOAA, U.S. Department of Commerce, 20 pp.

  • Cressman, G. P., 1959: An operational objective analysis system. Mon. Wea. Rev., 87 , 367374.

  • Douglas, M. W., and J. C. Leal, 2003: Summertime surges over the Gulf of California: Aspects of their climatology, mean structure, and evolution from radiosonde, NCEP reanalysis, and rainfall data. Wea. Forecasting, 18 , 5574.

    • Search Google Scholar
    • Export Citation
  • Douglas, M. W., R. A. Maddox, K. Howard, and S. Reyes, 1993: The Mexican monsoon. J. Climate, 6 , 16651677.

  • Fuller, R. D., and D. J. Stensrud, 2000: The relationship between tropical easterly waves and surges over the Gulf of California during the North American monsoon. Mon. Wea. Rev., 128 , 29832989.

    • Search Google Scholar
    • Export Citation
  • Glahn, H. R., T. L. Chambers, W. S. Richardson, and H. P. Perrotti, 1985: Objective map analysis for the Local AFOS MOS program. NOAA Tech. Memo. NWS TDL 75, National Weather Service, NOAA, U.S. Department of Commerce, 34 pp.

  • Hartmann, D. L., and E. D. Maloney, 2001: The Madden–Julian oscillation, barotropic dynamics, and North Pacific tropical cyclone formation. Part II: Stochastic barotropic modeling. J. Atmos. Sci., 58 , 25592570.

    • Search Google Scholar
    • Export Citation
  • Higgins, R. W., and W. Shi, 2001: Intercomparison of the principal modes of interannual and intraseasonal variability of the North American monsoon system. J. Climate, 14 , 403417.

    • Search Google Scholar
    • Export Citation
  • Higgins, R. W., W. Shi, E. Yarosh, and R. Joyce, 2000: Improved United States Precipitation Quality Control System and Analysis. NCEP/Climate Prediction Center Atlas No. 7, 40 pp.

  • Higgins, R. W., W. Shi, and C. Hain, 2004: Relationships between Gulf of California moisture surges and precipitation in the southwestern United States. J. Climate, 17 , 29832997.

    • Search Google Scholar
    • Export Citation
  • Kalnay, E. M., and Coauthors, 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc., 77 , 437471.

  • Madden, R. A., and P. R. Julian, 1971: Detection of a 40–50 day oscillation in the zonal wind in the tropical Pacific. J. Atmos. Sci., 28 , 702708.

    • Search Google Scholar
    • Export Citation
  • Madden, R. A., and P. R. Julian, 1994: Observations of the 40–50 day tropical oscillation—A review. Mon. Wea. Rev., 122 , 814837.

  • Maloney, E. D., and D. L. Hartmann, 1998: Frictional moisture convergence in a composite life cycle of the Madden–Julian oscillation. J. Climate, 11 , 23872403.

    • Search Google Scholar
    • Export Citation
  • Maloney, E. D., and D. L. Hartmann, 2000: Modulation of eastern North Pacific hurricanes by the Madden–Julian oscillation. J. Climate, 13 , 14511460.

    • Search Google Scholar
    • Export Citation
  • Maloney, E. D., and D. L. Hartmann, 2001: The Madden–Julian oscillation, barotropic dynamics, and North Pacific tropical cyclone formation. Part I: Observations. J. Atmos. Sci., 58 , 25452558.

    • Search Google Scholar
    • Export Citation
  • Stensrud, D. J., R. L. Gall, and M. K. Nordquist, 1997: Surges over the Gulf of California during the Mexican monsoon. Mon. Wea. Rev., 125 , 417437.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 750 166 19
PDF Downloads 572 126 17