Validation of parametrisations for the meridional energy and moisture transport used in simple climate models

Schmittner, A.; Appenzeller, C.; Stocker, T. F. (2000). Validation of parametrisations for the meridional energy and moisture transport used in simple climate models. Climate dynamics, 16(1), pp. 63-77. Springer-Verlag 10.1007/PL00007922

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Parametrisations of meridional energy and moisture transport used in zonally averaged climate models are validated using reanalysis data and results from a doubling CO2-experiment from a general circulation model. Global meridional fluxes of moisture and sensible heat are calculated by integrating surface and top-of-the-atmosphere vertical fluxes from one pole to the other. The parametrisations include an eddy-diffusion term, representing down-gradient transport of specific humidity and temperature due to the transient atmospheric eddies at mid- and high latitudes, and simple representations of the mean meridional circulation. Qualitative and quantitative agreement between the increased hydrological cycle in the 2×CO2-run from the GCM and the parametrisation is found. The performance for the sensible heat flux shows larger differences to the GCM results, particularly at low latitudes. Seasonal variations of the moisture and sensible heat transport are well captured by parametrisations including the influence of the mean meridional circulation. Interannual variability cannot be simulated. An examination of the parametrisations on different spatial scales suggests that they should not be used for small scales. Furthermore, two closures for the zonal distribution of precipitation were examined. They are used in zonally averaged atmosphere models coupled to an ocean model with different ocean basins at one latitudinal belt. An assessment of both the reanalysis data and the GCM results shows that both closures exhibit very similar behaviour and are valid in the long-term mean and seasonal cycle. Interannual variability is not captured well. They become invalid for spatial scales smaller than 10⁰.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Climate and Environmental Physics

UniBE Contributor:

Stocker, Thomas

Subjects:

500 Science > 530 Physics

ISSN:

0930-7575

Publisher:

Springer-Verlag

Language:

English

Submitter:

BORIS Import 2

Date Deposited:

31 Aug 2021 15:16

Last Modified:

05 Dec 2022 15:52

Publisher DOI:

10.1007/PL00007922

BORIS DOI:

10.48350/158495

URI:

https://boris.unibe.ch/id/eprint/158495

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