Publication Abstracts

Xie et al. 2002

Xie, S., K.-M. Xu, R.T. Cederwall, P. Bechtold, A.D. Del Genio, S.A. Klein, D.G. Cripe, S.J. Ghan, D. Gregory, S.F. Iacobellis, S.K. Krueger, U. Lohmann, J.C. Petch, D.A. Randall, L.D. Rotstayn, R.C.J. Somerville, Y.C. Sud, K. von Salzen, G.K. Walker, A. Wolf, J.J. Yio, G.J. Zhang, and M. Zhang, 2002: Intercomparison and evaluation of cumulus parameterizations under summertime midlatitude continental conditions. Q. J. Roy. Meteorol. Soc., 128, 1095-1136, doi:10.1256/003590002320373229.

This study reports the Single-Column Model (SCM) part of the Atmospheric Radiation Measurement (ARM) / the Global Energy and Water-cycle Experiment (GEWEX) Cloud System Study (GCSS) joint SCM and Cloud-Resolving Model (CRM) Case 3 intercomparison study, with a focus on evaluation of cumulus parameterizations used in SCMs. Fifteen SCMs are evaluated under summertime midlatitude continental conditions using data collected at the ARM Southern Great Plains (SGP) site during Summer 1997 Intensive Operational Period (IOP). Results from ten CRMs are also used to diagnose problems in the SCMs.

It is shown that most SCMs can generally capture well the convective events that were well developed within the SCM domain while most of them have difficulties of simulating the occurrence of those convective events that occurred only within a small part of the domain. All models significantly underestimate the surface stratiform precipitation. A third of them produce large errors in surface precipitation and thermodynamic structures. Deficiencies in convective triggering mechanisms are thought to be one of the major reasons. Using a triggering mechanism that is based on the vertical integral of parcel buoyant energy without additional appropriate constraints results in overactive convection, which in turn leads to large systematic warm/dry biases in the troposphere. It is also shown that a non-penetrative convection scheme can underestimate the depth of instability for midlatitude convection, which leads to large systematic cold/moist biases in the troposphere.

SCMs agree quantitatively well with CRMs in the updraft mass fluxes while most models significantly underestimate the downdraft mass fluxes. Neglect of mesoscale updraft and downdraft mass fluxes in the SCMs contributes to a considerable amount of the discrepancies between the SCMs and the CRMs. In addition, uncertainties in the diagnosed mass fluxes in the CRMs and deficiencies with cumulus parameterizations are not negligible.

Similar results are obtained in the sensitivity tests when different forcing approaches are used. Finally, sensitivity tests from an SCM indicate that its simulations can be greatly improved when its triggering mechanism and closure assumption are improved.

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BibTeX Citation

  author={Xie, S. and Xu, K.-M. and Cederwall, R. T. and Bechtold, P. and Del Genio, A. D. and Klein, S. A. and Cripe, D. G. and Ghan, S. J. and Gregory, D. and Iacobellis, S. F. and Krueger, S. K. and Lohmann, U. and Petch, J. C. and Randall, D. A. and Rotstayn, L. D. and Somerville, R. C. J. and Sud, Y. C. and von Salzen, K. and Walker, G. K. and Wolf, A. and Yio, J. J. and Zhang, G. J. and Zhang, M.},
  title={Intercomparison and evaluation of cumulus parameterizations under summertime midlatitude continental conditions},
  journal={Q. J. Roy. Meteorol. Soc.},

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RIS Citation

ID  - xi01000b
AU  - Xie, S.
AU  - Xu, K.-M.
AU  - Cederwall, R. T.
AU  - Bechtold, P.
AU  - Del Genio, A. D.
AU  - Klein, S. A.
AU  - Cripe, D. G.
AU  - Ghan, S. J.
AU  - Gregory, D.
AU  - Iacobellis, S. F.
AU  - Krueger, S. K.
AU  - Lohmann, U.
AU  - Petch, J. C.
AU  - Randall, D. A.
AU  - Rotstayn, L. D.
AU  - Somerville, R. C. J.
AU  - Sud, Y. C.
AU  - von Salzen, K.
AU  - Walker, G. K.
AU  - Wolf, A.
AU  - Yio, J. J.
AU  - Zhang, G. J.
AU  - Zhang, M.
PY  - 2002
TI  - Intercomparison and evaluation of cumulus parameterizations under summertime midlatitude continental conditions
JA  - Q. J. Roy. Meteorol. Soc.
VL  - 128
SP  - 1095
EP  - 1136
DO  - 10.1256/003590002320373229
ER  -

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