Advertisement

Boundary-Layer Meteorology

, Volume 83, Issue 3, pp 463–477 | Cite as

A DYNAMICAL MODEL FOR URBAN HEAT ISLANDS

  • JONG-JIN BAIK
  • HYE-YEONG CHUN
Article

Abstract

Effects of nonlinearity on theairflow past an urban heat island and precipitationchange downwind, are investigated analytically in thecontext of the weakly nonlinear response of a stablystratified uniform flow to specified heating. Theheating structure is assumed to be bell-shaped in thehorizontal and exponentially decreasing with height.The forcing to the first-order equation exhibitscooling in the concentrated low-level heating region.The linear solution component shows upward motiondownstream as suggested by many previous studies. Theweakly nonlinear solution component shows downward orupward motion downstream depending on the heatingdepth. It is proposed that when the heating depth islarge, but still within a valid range of theperturbation expansion, the linear and weaklynonlinear effects constructively work together toproduce enhanced upward motion on the downstream side,not far from the heating centre. This explains toa greater extent the precipitation enhancement downstream ofthe heat island than is possible from the linear effect alone. Itis also proposed that when the heating depth is small,the linear and weakly nonlinear effects destructivelywork together to reduce upward motion on thedownstream side, not far from the heating centre. Thisexplains to a greater extent the lack of precipitation enhancementdownstream than is possible from the linear effect alone.

Urban heat island Stably stratified flow Diabatic forcing Weakly nonlinear response Internal gravity wave 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Baik, J.-J.: 1992, 'Response of a Stably Stratified Atmosphere to Low-LevelHeating-An Application to the Heat Island Problem', J. Appl. Meteorol. 31, 291–303.Google Scholar
  2. Baik, J.-J. and Chun, H.-Y.: 1996, 'Effects of Nonlinearity on the Atmospheric Flow Response to Low-Level Heating in a Uniform Flow', J. Atmos. Sci. 53, 1856–1869.Google Scholar
  3. Booker, J. R. and Bretherton, F. P.: 1967, 'The Critical Layer for Internal Gravity Waves in a Shear Flow', J. Fluid Mech. 27, 513–539.Google Scholar
  4. Changnon, S. A., Shealy, B. T., and Scott, R. W.: 1991, 'Precipitation Changes in Fall,Winter, and Spring Caused by St. Louis', J. Appl. Meteorol. 30, 126–134.Google Scholar
  5. Chun, H.-Y. and Baik, J.-J.: 1994, 'Weakly Nonlinear Response of a Stably Stratified Atmosphere to Diabatic Forcing in a Uniform Flow', J. Atmos. Sci. 51, 3109–3121.Google Scholar
  6. Lin, Y.-L. and Chun, H.-Y.: 1991, 'Effects of Diabatic Cooling in a Shear Flow with a Critical Level', J. Atmos. Sci. 48, 2476–2491.Google Scholar
  7. Lin, Y.-L. and Smith, R. B.: 1986, 'Transient Dynamics of Airflow near a Local Heat Source', J. Atmos. Sci. 43, 40–49.Google Scholar
  8. Oke, T. R.: 1973, 'City Size and the Urban Heat Island', Atmos. Environ. 7, 769–779.Google Scholar
  9. Olfe, D. B. and Lee, R. L.: 1971, 'Linearized Calculations of Urban Heat Island Convection Effects', J. Atmos. Sci. 28, 1374–1388.Google Scholar
  10. Pielke, R. A.: 1984, Mesoscale Meteorological Modeling, Academic Press, 612 pp.Google Scholar
  11. Smith, R. B. and Lin, Y.-L.: 1982, 'The Addition of Heat to a Stratified Airstream with Application to the Dynamics of Orographic Rain', Quart. J. Roy. Meteorol. Soc. 108, 353–378.Google Scholar

Copyright information

© Kluwer Academic Publishers 1997

Authors and Affiliations

  • JONG-JIN BAIK
    • 1
  • HYE-YEONG CHUN
    • 2
  1. 1.Department of Environmental Science and EngineeringKwangju Institute of Science and TechnologyKwangjuKorea
  2. 2.Department of Astronomy and Atmospheric SciencesYonsei UniversitySeoulKorea

Personalised recommendations