The Effects of Computational Resolution on Limited-Area Solutions of the Barotropic Vorticity Equation.
Abstract
Numerical experiments with the barotropic vorticity equation are carried out to examine the effects of the computational resolution on the forecast accuracy within a limited region. The experiments assume that wind is measured and predicted at prescribed times on a set of uniformly distributed grid points with a grid distance of abut 750 km. The required initial and boundary conditions for a given computational resolution are estimated through interpolation. The finite-difference analogue of the vorticity equation is obtained using the Shuman algorithm and the leap-frog scheme. The time integration is extended for 12 hours. The observed winds are given by the values of the Rossby-Haurwitz waves and the forecast errors are defined by the differences between the predicted and observed values. Three levels of computational resolution, namely, the single-, double-, and quadruple resolutions are considered, in which the single resolution network coincides with the observational network. Two spatial interpolation procedures, the bilinear and the 16-point least-squares biquadratic interpolations and the linear time interpolation, are used to obtain estimates of requisite initial and boundary values.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 19, 1981
- Accession Number
- ADA100254
Entities
People
- Chien-hsiung Yang
Organizations
- Air Force Research Laboratory