Show simple item record

contributor authorNigam, Sumant
date accessioned2017-06-09T14:26:01Z
date available2017-06-09T14:26:01Z
date copyright1985/12/01
date issued1985
identifier issn0022-4928
identifier otherams-19173.pdf
identifier urihttp://onlinelibrary.yabesh.ir/handle/yetl/4155260
description abstractThe minimum meridional resolution needed for an adequate numerical simulation of the linear and ?quasi-linear? baroscopic vorticity dynamics in the vicinity of a critical latitude is determined by using a semi-spectral nondivergent barotropic model on a sphere. The high resolution barotropic calculations of Nigam and Held in which the stationary waves are forced by the earth's orography are repeated with several lower meridional resolutions. Comparison of the lower resolution simulations with the higher resolution ones (the ?true solutions?) shows the quality of both the linear and the quasi-linear simulations to deteriorate with decreasing meridional resolution. An unresolved critical latitude results in spurious sensitivity of the steady linear response to the tropical zonal wind structure, whereas a critical latitude resolved using a strong damping coefficient rather than a fine latitudinal grid may result in the attenuation of any genuinely reflected wave at the critical latitude. For a Rayleigh damping coefficient of (13.5 days)?1, a latitudinal resolution of ?? <3° is found to be sufficient for an adequate simulation of planetary waves in the quasi-linear model; the linear model, for a commensurate quality of simulation, needs a ??< 2°. While this choice of the damping coefficient is arbitrary to some extent, the obtained solutions do have structure similar to that seen in the observed wintertime stationary planetary waves.
publisherAmerican Meteorological Society
titleOn the Adequacy of Meridional Resolution of Linear and Quasi-Linear Barotropic Models
typeJournal Paper
journal volume42
journal issue23
journal titleJournal of the Atmospheric Sciences
identifier doi10.1175/1520-0469(1985)042<2493:OTAOMR>2.0.CO;2
journal fristpage2493
journal lastpage2505
treeJournal of the Atmospheric Sciences:;1985:;Volume( 042 ):;issue: 023
contenttypeFulltext


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record