Publication Abstracts

Lynn and Tao 2001

Lynn, B.H., and W.-K. Tao, 2001: A parameterization for the triggering of landscape-generated moist convection. Part II: Zero-order and first-order closure. J. Atmos. Sci., 58, 593-607, doi:10.1175/1520-0469(2001)058<0593:APFTTO>2.0.CO;2.

To improve the triggering of clouds over landscape heterogeneity, it is suggested that the forcing by mesoscale circulations generated by landscape patches be included. For this purpose, it is suggested that a relatively simple zero-order closure be used to obtain a triggering parcel's mesoscale perturbation vertical velocity, potential temperature, and specific humidity. In combination with a turbulent fluctuation averaged over a parcel area, one can obtain a parcel's (total) velocity, temperature, and moisture. The authors used similarity theory to parameterize the mesoscale perturbations, using a dataset generated by a three-dimensional, high-resolution cumulus ensemble model with west-to-east land surface patches.

Alternatively, the authors used one-dimensional budget equations that contain mesoscale and turbulent fluctuations (and source terms) to obtain the vertical profile of potential temperature and specific humidity within a triggering parcel. Here, it is suggested that first-order closure be used; these equations with first-order closure should provide more realistic profiles of temperature and moisture within a triggering parcel than with the zero-order scheme above. This is especially the case when moist (cloud) processes occur. An analysis of the model-produced dataset indicated that parameterizations for two terms needed to be developed to close the budget equations: the vertical flux of the mesoscale temperature and moisture. Similarity theory is used to parameterize these fluxes.

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BibTeX Citation

@article{ly02000x,
  author={Lynn, B. H. and Tao, W.-K.},
  title={A parameterization for the triggering of landscape-generated moist convection. Part II: Zero-order and first-order closure},
  year={2001},
  journal={Journal of the Atmospheric Sciences},
  volume={58},
  pages={593--607},
  doi={10.1175/1520-0469(2001)058%3C0593%3AAPFTTO%3E2.0.CO;2},
}

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RIS Citation

TY  - JOUR
ID  - ly02000x
AU  - Lynn, B. H.
AU  - Tao, W.-K.
PY  - 2001
TI  - A parameterization for the triggering of landscape-generated moist convection. Part II: Zero-order and first-order closure
JA  - J. Atmos. Sci.
JO  - Journal of the Atmospheric Sciences
VL  - 58
SP  - 593
EP  - 607
DO  - 10.1175/1520-0469(2001)058%3C0593%3AAPFTTO%3E2.0.CO;2
ER  -

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