Determination of eddy-diffusivity in the lowermost stratosphere

Hegglin, M. I. ORCID: https://orcid.org/0000-0003-2820-9044, Brunner, D., Peter, T., Staehelin, J., Wirth, V., Hoor, P. and Fischer, H. (2005) Determination of eddy-diffusivity in the lowermost stratosphere. Geophysical Research Letters, 32 (13). L13812. ISSN 0094-8276 doi: 10.1029/2005GL022495

Abstract/Summary

We present a 2D-advection-diffusion model that simulates the main transport pathways influencing tracer distributions in the lowermost stratosphere (LMS). The model describes slow diabatic descent of aged stratospheric air, vertical (cross-isentropic) and horizontal (along isentropes) diffusion within the LMS and across the tropopause using equivalent latitude and potential temperature coordinates. Eddy diffusion coefficients parameterize the integral effect of dynamical processes leading to small scale turbulence and mixing. They were specified by matching model simulations to observed CO distributions. Interestingly, the model suggests mixing across isentropes to be more important than horizontal mixing across surfaces of constant equivalent latitude, shining new light on the interplay between various transport mechanisms in the LMS. The model achieves a good description of the small scale tracer features at the tropopause with squared correlation coefficients R2 = 0.72…0.94.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/33354
Identification Number/DOI	10.1029/2005GL022495
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	American Geophysical Union
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