Wet-Bulb Temperature from Relative Humidity and Air Temperature

Roland Stull University of British Columbia, Vancouver, British Columbia, Canada

Search for other papers by Roland Stull in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

An equation is presented for wet-bulb temperature as a function of air temperature and relative humidity at standard sea level pressure. It was found as an empirical fit using gene-expression programming. This equation is valid for relative humidities between 5% and 99% and for air temperatures between −20° and 50°C, except for situations having both low humidity and cold temperature. Over the valid range, errors in wet-bulb temperature range from −1° to +0.65°C, with mean absolute error of less than 0.3°C.

Corresponding author address: Roland Stull, Earth and Ocean Sciences Dept., University of British Columbia, 6339 Stores Rd., Vancouver, BC V6T 1Z4, Canada. E-mail: rstull@eos.ubc.ca

Abstract

An equation is presented for wet-bulb temperature as a function of air temperature and relative humidity at standard sea level pressure. It was found as an empirical fit using gene-expression programming. This equation is valid for relative humidities between 5% and 99% and for air temperatures between −20° and 50°C, except for situations having both low humidity and cold temperature. Over the valid range, errors in wet-bulb temperature range from −1° to +0.65°C, with mean absolute error of less than 0.3°C.

Corresponding author address: Roland Stull, Earth and Ocean Sciences Dept., University of British Columbia, 6339 Stores Rd., Vancouver, BC V6T 1Z4, Canada. E-mail: rstull@eos.ubc.ca
Save
  • Bakhshaii, A., and R. Stull, 2009: Deterministic ensemble forecasts using gene-expression programming. Wea. Forecasting, 24, 14311451.

    • Search Google Scholar
    • Export Citation
  • Bohren, C. F., and B. A. Albrecht, 1998: Atmospheric Thermodynamics. Oxford University Press, 402 pp.

  • Ferreira, C., 2006: Gene Expression Programming: Mathematical Modeling by an Artificial Intelligence. 2nd ed. Springer, 478 pp.

  • Roebber, P. J., 2010: Seeking consensus: A new approach. Mon. Wea. Rev., 138, 44024415.

  • Stull, R., 2011: Meteorology for Scientists and Engineers. 3rd ed. Discount Textbooks, 924 pp. [Available online at http://www.eos.ubc.ca/courses/atsc201/MSE3.html.]

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 56399 12998 1272
PDF Downloads 46930 10225 879