Simulations of the North American Monsoon System. Part I: Model Analysis of the 1993 Monsoon Season

Stephen M. Saleeby Colorado State University, Fort Collins, Colorado

Search for other papers by Stephen M. Saleeby in
Current site
Google Scholar
PubMed
Close
and
William R. Cotton Colorado State University, Fort Collins, Colorado

Search for other papers by William R. Cotton in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

The North American monsoon system is known to produce significant summertime precipitation on the west coast of Mexico and the southwestern United States, with some areas receiving greater than 50% of their yearly rainfall between the months of July and September. The onset of the monsoon is attributed to a shift in the large-scale upper-level anticyclonic flow over the central United States, and the associated increases in moisture flux and resulting precipitation are tied to the low-level jets from the Gulf of California and the Gulf of Mexico. Individual monsoon surge events vary in intensity, as does the magnitude of the diurnal cycle of the low-level jets and precipitation. Numerical modeling and forecasting of these interacting large-and mesoscale monsoon features is often difficult in terms of accurately recreating the varying flow regimes aloft and near the surface and over both the flat and steep terrain that are encompassed within the monsoon region of influence.

The Regional Atmospheric Modeling System (RAMS) at Colorado State University has been utilized to investigate seasonal monsoon simulations for the 1988 (United States drought), 1993 (Midwest flood), and 1997 (El Niño year) monsoon seasons. In Part I of this paper the credibility of RAMS, as far as its ability to reproduce observed features of the North American monsoon system, is evaluated. Part II provides interseasonal comparisons of model-simulated monsoon features from the three simulated extreme seasons and results of sensitivity studies to SSTs and soil moisture variability. Part III presents the development of potential vorticity anomalies associated with convection over Mexico and their downstream influence over the central United States.

Corresponding author address: Stephen M. Saleeby, Atmospheric Science Dept., Colorado State University, Fort Collins, CO 80523. Email: smsaleeb@atmos.colostate.edu

Abstract

The North American monsoon system is known to produce significant summertime precipitation on the west coast of Mexico and the southwestern United States, with some areas receiving greater than 50% of their yearly rainfall between the months of July and September. The onset of the monsoon is attributed to a shift in the large-scale upper-level anticyclonic flow over the central United States, and the associated increases in moisture flux and resulting precipitation are tied to the low-level jets from the Gulf of California and the Gulf of Mexico. Individual monsoon surge events vary in intensity, as does the magnitude of the diurnal cycle of the low-level jets and precipitation. Numerical modeling and forecasting of these interacting large-and mesoscale monsoon features is often difficult in terms of accurately recreating the varying flow regimes aloft and near the surface and over both the flat and steep terrain that are encompassed within the monsoon region of influence.

The Regional Atmospheric Modeling System (RAMS) at Colorado State University has been utilized to investigate seasonal monsoon simulations for the 1988 (United States drought), 1993 (Midwest flood), and 1997 (El Niño year) monsoon seasons. In Part I of this paper the credibility of RAMS, as far as its ability to reproduce observed features of the North American monsoon system, is evaluated. Part II provides interseasonal comparisons of model-simulated monsoon features from the three simulated extreme seasons and results of sensitivity studies to SSTs and soil moisture variability. Part III presents the development of potential vorticity anomalies associated with convection over Mexico and their downstream influence over the central United States.

Corresponding author address: Stephen M. Saleeby, Atmospheric Science Dept., Colorado State University, Fort Collins, CO 80523. Email: smsaleeb@atmos.colostate.edu

Save
  • Adang, T. C., and R. L. Gall, 1989: Structure and dynamics of the Arizona monsoon boundary. Mon. Wea. Rev, 117 , 14231438.

  • Badan-Dangon, A., C. E. Dorman, M. A. Merrifield, and C. D. Winant, 1991: The lower atmosphere over the Gulf of California. J. Geophys. Res, 96 , 877896.

    • Search Google Scholar
    • Export Citation
  • Blanchard, B. J., M. J. McFarland, T. J. Schmugge, and E. Rhoades, 1981: Estimation of soil moisture with API algorithms and microwave emission. Water Resour. Bull, 17 , 767774.

    • Search Google Scholar
    • Export Citation
  • Brenner, I. S., 1974: A surge of maritime tropical air—Gulf of California to the southwestern United States. Mon. Wea. Rev, 102 , 375389.

    • Search Google Scholar
    • Export Citation
  • Bryson, R. A., and W. P. Lowry, 1955: The synoptic climatology of the Arizona summer precipitation singularity. Bull. Amer. Meteor. Soc, 36 , 329339.

    • Search Google Scholar
    • Export Citation
  • Bryson, R. A., and F. K. Hare, 1974: The climates of North America. Climates of North America, World Survey of Climatology, Vol. 11, Elsevier, 1–45.

    • Search Google Scholar
    • Export Citation
  • Carbone, R. E., J. D. Tuttle, D. A. Ahijevych, and S. B. Trier, 2002: Inferences of predictability associated with warm season precipitation episodes. J. Atmos. Sci, 59 , 20332056.

    • Search Google Scholar
    • Export Citation
  • Carleton, A. M., 1986: Synoptic–dynamic character of “bursts” and “breaks” in the south-west U.S. summer precipitation singularity. J. Climatol, 6 , 605623.

    • Search Google Scholar
    • Export Citation
  • Carleton, A. M., 1987: Summer circulation of the American southwest, 1945– 1984. Ann. Assoc. Amer. Geogr, 77 , 619634.

  • Carleton, A. M., D. A. Carpenter, and P. J. Weser, 1990: Mechanisms of interannual variability of the southwest United States summer rainfall maximum. J. Climate, 3 , 9991015.

    • Search Google Scholar
    • Export Citation
  • Castro, C. L., W. Y. Y. Cheng, A. B. Beltran, R. A. Pielke Sr., and W. R. Cotton, 2002: The incorporation of the Kain–Fritsch cumulus parameterization scheme in RAMS with a terrain-adjusted trigger function. Fifth RAMS Users and Related Applications Workshop, Santorini, Greece, ATMET, Inc.

    • Search Google Scholar
    • Export Citation
  • Cavazos, T., A. C. Comrie, and D. M. Liverman, 2002: Intraseasonal variability associated with wet monsoons in southeast Arizona. J. Climate, 15 , 24772490.

    • Search Google Scholar
    • Export Citation
  • Cotton, W. R., R. L. George, P. J. Wetzel, and R. L. McAnelly, 1983: A long-lived mesoscale convective complex. Part I: The mountain-generated component. Mon. Wea. Rev, 111 , 18931918.

    • Search Google Scholar
    • Export Citation
  • Cotton, W. R., and Coauthors, 2003: RAMS 2001: Current status and future directions. Meteor. Atmos. Phys, 82 , 529.

  • Douglas, M. W., 1995: The summertime low-level jet over the Gulf of California. Mon. Wea. Rev, 123 , 23342347.

  • Douglas, M. W., and S. Li, 1996: Diurnal variation of the lower-tropospheric flow over the Arizona low desert from SWAMP-1993 observations. Mon. Wea. Rev, 124 , 12111224.

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

  • Fritsch, J. M., R. J. Kain, and C. R. Chelius, 1986: The contribution of mesoscale convective weather systems to the warm-season precipitation in the United States. J. Climate Appl. Meteor, 25 , 13331345.

    • Search Google Scholar
    • Export Citation
  • 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
  • Gochis, D. J., W. J. Shuttleworth, and Z. L. Yang, 2002: Sensitivity of the modeled North American monsoon regional climate to convective parameterization. Mon. Wea. Rev, 130 , 12821298.

    • Search Google Scholar
    • Export Citation
  • Hales Jr., J. E., 1972: Surges of maritime tropical air northward over the Gulf of California. Mon. Wea. Rev, 100 , 298306.

  • Harrington, J. Y., 1997: The effects of radiative and microphysical processes on simulated warm and transition season Arctic stratus. Ph.D. dissertation, Dept. of Atmospheric Science Paper No. 637, Colorado State University, Fort Collins, CO, 289 pp.

    • Search Google Scholar
    • Export Citation
  • Harrington, J. Y., T. Reisin, W. R. Cotton, and S. M. Kreidenweis, 1999: Cloud resolving simulations of Arctic stratus. Part II: Transition-season clouds. Atmos. Res, 55 , 4575.

    • Search Google Scholar
    • Export Citation
  • Higgins, R. W., Y. Yao, and X. Wang, 1997: Influence of the North American monsoon system on the U.S. summer precipitation regime. J. Climate, 10 , 26002622.

    • Search Google Scholar
    • Export Citation
  • Higgins, R. W., K. C. Mo, and Y. Yao, 1998: Interannual variability of the U.S. summer precipitation regime with emphasis on the southwestern monsoon. J. Climate, 11 , 25822606.

    • Search Google Scholar
    • Export Citation
  • Jirak, I. L., W. R. Cotton, and R. L. McAnelly, 2003: Satellite and radar survey of mesoscale convective system development. Mon. Wea. Rev, 131 , 24282449.

    • Search Google Scholar
    • Export Citation
  • Jurwitz, L., 1953: Arizona's two-season rainfall pattern. Weatherwise, . 6 (4) 9699.

  • Kain, J. S., and J. M. Fritsch, 1990: A one-dimensional entraining/ detraining plume model and its application in convective parameterization. J. Atmos. Sci, 47 , 27842802.

    • Search Google Scholar
    • Export Citation
  • Kain, J. S., and J. M. Fritsch, 1992: The role of the convective “triggering function” in numerical forecasts of mesoscale convective systems. Meteor. Atmos. Phys, 49 , 93106.

    • Search Google Scholar
    • Export Citation
  • Kain, J. S., and J. M. Fritsch, 1993: Convective parameterization for mesoscale models: The Kain–Fritsch scheme. The Representation of Cumulus Convection in Numerical Models, Meteor. Monogr., No. 46, Amer. Meteor. Soc., 165–170.

    • Search Google Scholar
    • Export Citation
  • Klemp, J. B., and R. B. Wilhelmson, 1978: The simulation of three-dimensional convective storm dynamics. J. Atmos. Sci, 35 , 10701096.

    • Search Google Scholar
    • Export Citation
  • Kuo, H. L., 1965: On formation and intensification of tropical cyclones through latent heat release by cumulus convection. J. Atmos. Sci, 22 , 4063.

    • Search Google Scholar
    • Export Citation
  • Kuo, H. L., 1974: Further studies of the parameterization of the influence of cumulus convection on large-scale flow. J. Atmos. Sci, 31 , 12321240.

    • Search Google Scholar
    • Export Citation
  • Maddox, R. A., 1980: Mesoscale convective complexes. Bull. Amer. Meteor. Soc, 61 , 13741387.

  • Mellor, G. L., and T. Yamada, 1974: A hierarchy of turbulence closure models for planetary boundary layers. J. Atmos. Sci, 31 , 17911806.

    • Search Google Scholar
    • Export Citation
  • Mo, K. C., J. N. Paegle, and R. W. Higgins, 1997: Atmospheric processes associated with summer floods and droughts in the central United States. J. Climate, 10 , 30283046.

    • Search Google Scholar
    • Export Citation
  • Nachamkin, J. E., and W. R. Cotton, 1998: Interacting solenoidal circulations and their role in convective orogenesis. Preprints, Eighth Conf. on Mountain Meteorology, Flagstaff, AZ, Amer. Meteor. Soc., 11.4.

    • Search Google Scholar
    • Export Citation
  • Reyes, S., and D. L. Cadet, 1988: The southwest branch of the North American monsoon during summer 1979. Mon. Wea. Rev, 116 , 11751187.

    • Search Google Scholar
    • Export Citation
  • Reynolds, R. W., and T. M. Smith, 1994: Improved global sea surface temperature analyses using optimum interpolation. J. Climate, . 7 , 929948.

    • Search Google Scholar
    • Export Citation
  • Sadler, J. C., M. A. Lander, A. M. Hori, and L. K. Oda, 1987: Pacific Ocean. Vol. 2. Tropical Marine Climatic Atlas, Dept. of Meteorology Atlas UHMET 87-02, University of Hawaii, 27 pp.

    • Search Google Scholar
    • Export Citation
  • Schmitz, J. T., and S. Mullen, 1996: Water vapor transport associated with the summertime North American monsoon as depicted by ECMWF analyses. J. Climate, 9 , 16211634.

    • Search Google Scholar
    • Export Citation
  • Smagorinsky, J., 1963: General circulation experiments with the primitive equations. Mon. Wea. Rev, 91 , 99164.

  • Stensrud, D. J., R. L. Gall, S. L. Mullen, and K. W. Howard, 1995: Model climatology of the Mexican monsoon. J. Climate, 8 , 17751794.

    • 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 monson. Mon. Wea. Rev, 125 , 417437.

    • Search Google Scholar
    • Export Citation
  • Tang, M., and E. R. Reiter, 1984: Plateau monsoons of the Northern Hemisphere: A comparison between North America and Tibet. Mon. Wea. Rev, 112 , 617637.

    • Search Google Scholar
    • Export Citation
  • Tripoli, G. J., and W. R. Cotton, 1989: Numerical study of an observed orogenic mesoscale convective system. Part I: Simulated genesis and comparison with observations. Mon. Wea. Rev, 117 , 273304.

    • Search Google Scholar
    • Export Citation
  • Uccellini, L. W., and D. R. Johnson, 1979: The coupling of upper and lower tropospheric jet streaks and implications for the development of severe convective storms. Mon. Wea. Rev, 107 , 682703.

    • Search Google Scholar
    • Export Citation
  • Walko, R. L., W. R. Cotton, J. L. Harrington, and M. P. Meyers, 1995: New RAMS cloud microphysics parameterization. Part I: The single-moment scheme. Atmos. Res, 38 , 2962.

    • Search Google Scholar
    • Export Citation
  • Wallace, J. M., 1975: Diurnal variations in precipitation and thunderstorm frequency over the conterminous United States. Mon. Wea. Rev, 103 , 406419.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 223 31 5
PDF Downloads 97 36 10