Hostname: page-component-848d4c4894-2pzkn Total loading time: 0 Render date: 2024-06-07T12:45:15.749Z Has data issue: false hasContentIssue false

The formation of atmospheric fronts downstream in a deformation field

Published online by Cambridge University Press:  29 March 2006

Brian J. Hoskins
Affiliation:
Geophysical Fluid Dynamics Program, Princeton University, Princeton, New Jersey Present address: U.K. Universities Atmospheric Modelling Group, University of Reading

Abstract

An analytical study is made of simple models of steady fronts in the atmosphere in which the temperature field is subjected to deformation as the fluid moves downstream in a large-scale horizontal flow. One fundamental approximation is made and then a Lagrangian method, in which fluid particles are identified by conservation of entropy and potential vorticity, and by Bernoulli's theorem, enables the steady problem to be solved. Solutions for models of surface fronts and upper tropospheric fronts are compared with those obtained from a model in which there is no variation along the front and the frontogenesis proceeds in time. If the thermal wind is comparable with the basic wind, and the potential vorticity is not negligible in some sense, the frontogenesis is increased where the thermal wind opposes the basic flow but, decreased where it reinforces the flow.

Type
Research Article
Copyright
© 1974 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bjerknes J.1919 On the structure of moving cyclones. Geofys. Publikasjoner, 1, 18.Google Scholar
Charney J. G.1947 The dynamics of long waves in a baroclinic westerly current. J. Meteor., 4, 135162.Google Scholar
Danielsen E. F.1968 Stratospheric-tropospheric exchange based on radioactivity.
Eady E. T.1949 Long waves and cyclone waves. Tellus, 1, 3352.Google Scholar
Hoskins B. J.1971 Atmospheric frontogenesis: some solutions. Quart. J. Roy. Met. Soc., 97, 139153.Google Scholar
Hoskins B. J.1972 Non-Boussinesq effects and further development in a model of upper tropospheric frontogenesis. Quart. J. Roy. Met. Soc., 98, 532541.Google Scholar
Hoskins B. J.1973 The surface pressure distribution in a simple frontogenesis model. U.K. Universities Atmos. Modelling Group Rep.Google Scholar
Hoskins, B. J. & Bretherton F. P.1972 Atmospheric frontogenesis models: mathematical formulation and solution. J. Atmos. Sci., 29, 1137.Google Scholar
Pedlosky J.1964 The stability of currents in the atmosphere and ocean: Part I. J. Atmos. Sci., 21, 201219.Google Scholar
Reed, R. J. & Danielsen E. F.1959 Fronts in the vicinity of the tropopause. Arch. Meteor. Geophys. Bioklim. A 11, 117.Google Scholar
Sanders F.1955 Investigation of the structure and dynamics of an intense surface frontal zone. J. Meteor., 12, 542552.Google Scholar
Stone P. H.1966 Frontogenesis by horizontal wind deformation fields. J. Atmos. Sci., 23 455465.Google Scholar
Williams, R. T. & Plotkin J.1968 Quasi-geostrophic frontogenesis. J. Atmos. Sci., 25, 201206.Google Scholar