A Study of Constant Absolute Vorticity Trajectories on Isentropic Surfaces
Carlstead, Edward M.
MetadataShow full item record
It is shown that constant absolute vorticity (CAV) trajectories are more useful on isentropic surfaces than on constant pressure surfaces. A form of the vorticity equation is derived by use of Lagrangian methods. This form is similar to the Rossby form, and ordinary methods of computing CAV trajectories can be used with isentropic charts. A series of isentropic streamline charts were prepared and CAV trajectories were constructed at certain points on these charts. CAV trajectories were also constructed on 500-mb charts for the same time. 24- and 48-hr forecasts of wind direction and speed were made from CAV trajectories on both sets of charts, and verified. The results of these forecasts are treated statistically, and forecasts from CAV trajectories on isentropic charts are shown to be significantly better than similar forecasts from 500-mb charts. The effects of the divergence term of the vorticity equation are discussed qualitatively.
The article of record as published may be found at http://dx.doi.org/10.1175/1520-0469
RightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
Showing items related by title, author, creator and subject.
Alberty, Ronnie L.; Van Sickle, Kenneth Lee (Monterey, California. Naval Postgraduate School, 1969); NPS-51A19081AOne and one-half hour isentropic trajectories obtained from an objective computer technique for the 308K, 312K, 320K and 332K isentropic surfaces are investigated for the May 28, 1967, severe local storm case in the National ...
Arnason, G.; Haltiner, G.J.; Frawley, M.J. (1962-05);Two iterative methods are described for obtaining horizontal winds from the pressure-height field by means of higher-order geostrophic approximations for the purpose of improving upon the geostrophic wind. The convergence ...
Boerlage, Andrew P. (Monterey, California. Naval Postgraduate School, 1989);Isentropic potential vorticity (IPV) fields calculated from the Na\7 Operational Regional Atmospheric Prediction System are analyzed to determine their usefulness as an aid to tropical cyclone recurvature forecasts. The ...