Matthews, Adrian J. ORCID: https://orcid.org/0000-0003-0492-1168 and Lander, Jason (1999) Physical and numerical contributions to the structure of Kelvin wave-CISK modes in a spectral transform model. Journal of the Atmospheric Sciences, 56 (23). pp. 4050-4058. ISSN 0022-4928
Preview |
PDF (matthewslander1999.pdf)
Download (158kB) | Preview |
Abstract
Nonlinear Kelvin wave-CISK modes'' are critically assessed as a possible mechanism for the Madden-Julian Oscillation (MJO) with a global spectral transform model and a one-dimensional analog. Convection is parametrized using a simple ``positive-only CISK'' scheme, where tropospheric diabatic heating is proportional to the low-level convergence, and is set to zero in regions of low-level divergence. Although the modes have many properties that are consistent with the MJO, they also have a serious drawback. The growth rate of unstable modes depends crucially on the width of the heating region, which is resolution dependent. The ``CISK catastrophe'' has not been averted, and the heating region collapses to the smallest localized scale that the model can support. This scale is larger than the model resolution, as measured by both the gridpoint-scale and the inverse wavenumber or half-zonal-wavelength of the highest wavenumber basis function, and is associated with the appearance of negative Gibbs fringes which are then cut off by the positive-only CISK parametrization.
Item Type: | Article |
---|---|
Faculty \ School: | Faculty of Science > School of Mathematics (former - to 2024) Faculty of Science > School of Environmental Sciences |
UEA Research Groups: | Faculty of Science > Research Groups > Centre for Ocean and Atmospheric Sciences Faculty of Science > Research Groups > Volcanoes@UEA (former - to 2018) Faculty of Science > Research Groups > Marine and Atmospheric Sciences (former - to 2017) Faculty of Science > Research Groups > Meteorology, Oceanography and Climate Dynamics (former - to 2017) Faculty of Science > Research Groups > Climate, Ocean and Atmospheric Sciences (former - to 2017) Faculty of Science > Research Groups > Fluids & Structures Faculty of Science > Research Groups > Numerical Simulation, Statistics & Data Science |
Depositing User: | Vishal Gautam |
Date Deposited: | 10 Mar 2011 12:37 |
Last Modified: | 07 Nov 2024 12:35 |
URI: | https://ueaeprints.uea.ac.uk/id/eprint/20947 |
DOI: | 10.1175/1520-0469(1999)056<4050:PANCTT>2.0.CO;2 |
Downloads
Downloads per month over past year
Actions (login required)
View Item |