A numerical model has been developed and tested, which is intended to become part of an ice warning system for airports, giving forecasts over 1 to 3 hours. The model, which is one-dimensional, extends from 100 cm below the runway surface to 15 M above it. In its present form the model predicts surface temperature and freezing or melting on the surface. The temperature field below the surface is advanced in time by numerical solution of the diffusion equation with variable thermal diffusivity. For the runway surface the energy balance equation is employed. The turbulent flux terms are obtained from flux-gradient relations. To initiate the model the temperature profile in the ground must be specified rather accurately. A method for this is presented. The boundary conditions required to run the model are: temperature, wind speed and water vapour pressure at 15 M, net incoming short wave radiation and incoming long wave radiation and furthermore the state of the runway surface, whether wet, dry or frozen. A detailed micrometeorological measurement program has been carried out at two airports in Sweden. Data from this program have been used to provide initiation and boundary values and to test predictions with the model. Calculations have been carried out with the model in a variety of conditions, the length of the forecasting period being about 2 hours. In all these tests, where the boundary conditions have been given from measurements, predicted and observed temperature profiles agree remarkably well. (TRRL)

  • Corporate Authors:

    Uppsala University, Sweden

    Box 256
    S-75105 Uppsala,   Sweden 
  • Authors:
    • Smedman-hoegstroem, A-S
  • Publication Date: 1979-9

Media Info

  • Features: Figures; References;
  • Pagination: 24 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00322172
  • Record Type: Publication
  • Source Agency: Swedish National Road and Transport Research Institute (VTI)
  • Report/Paper Numbers: Monograph
  • Files: ITRD, TRIS
  • Created Date: May 21 1981 12:00AM