WCRP GEWEX (GMPP) GCSS PCS InterComp

TWP-ICE case: Convective transport, microphysics and the TTL

The use of TWP-ICE data and idealised tracers to model deep convection over the ocean and land.

• CRM overview web pages (contact Ann Fridlind)
• Leaders: Ann Fridlind; Maria Russo; Laura Davies & Christian Jakob

Case 5: Transition of tropical convection

The use of TOGA COARE data to model the transition from suppressed to deep convection.

• Overview web page
• CRM, SCM and LAMs web page:
• NWP models web page
• Paper accepted by QJ subject to minor revisions: Modelling suppressed and active convection. Comparison between three numerical weather models. M. Willett, P. Bechtold, J. C. Petch, S.F. Milton and D.L. Williamson.
• Paper in preparation: Convective processes during the suppressed phase of the Madden-Julian Oscillation. S. J. Woolnough, P. Bechtold, P. Blossey, J.-P. Chaboureau, T. Hosomi, S. Iacobellis, Y. Luo, J.C. Petch, R. Wong and S. Xie
• Leaders: Steve Woolnough, Martin Willett and Jon Petch

Case 4: Daytime convective development over land

An idealized case based on TRMM-LBA observations. The purpose of this case was to investigate the development of the daytime convective boundary layer over land and the transition from shallow to deep convection.

• Paper:Daytime convective development over land: a model intercomparison based on LBA observations Quarterly Journal of the Royal Meteorological Society.  132, 317-344
• Web page
• Leader: Wojciech W. Grabowski, NCAR (with data provided by Steve Lang, NASA Goddard)

Case 3: Continental deep convection

A continental case based on intensive measurements taken at the ARM (Atmospheric Radiation Measurement program) Southern Great Plains experimental site during June and July 1997. This was done in collaboration with the ARM Single Column Modeling Group.

• Paper:Xu, K.-M., R. T. Cederwall, L. J. Donner, W. W. Grabowski, F. Guichard, D. E. Johnson, M. Khairoutdinov, S. K. Krueger, J. C. Petch, D. A. Randall, C. J. Seman, W.-K. Tao, D. Wang, S. C. Xie, J. J. Yio, and M.-H. Zhang, 2001: An Intercomparison of Cloud-Resolving Models with the ARM Summer 1997 IOP Data. Quarterly Journal of the Royal Meteorological Society.  128, 593-62
• Web Page: http://www.mmm.ucar.edu/gcss-wg4/gcss/case3.html
• Leaders: Steve Krueger and Kuan-Man Xu

Case 2a: Tropical oceanic deep convection

Two- and three-dimensional modeling of the evolution of convection subjected to observed, time-dependent, large-scale forcing on a time scale of a week. Initial conditions for the simulations, the evolving large-scale forcing and the data used in model evaluation are averages over the TOGA COARE Intensive Flux Array (IFA).

• Paper: In progress
• Web page: http://www.met.utah.edu/skrueger/gcss/case2.html
• Leader: Steve Krueger

Case 2b: radiation code offline intercomparison

The purpose of this exercise is to examine and compare the surface heat fluxes, radiative heating rates and fluxes, and microphysical fields from the CRM and SCM models at one instant of time during the Case 2 period.

• Paper: In progress
• Web page: http://rsd.gsfc.nasa.gov/users/djohnson/gcsswg4/
• Leaders:Wei-Kuo Tao and Dan Johnson

Case 1: Tropical oceanic squall line

Two- and three-dimensional modeling of a squall line on a time scale of a few hours. The initial conditions and evaluation data sets were obtained as part of an intensive observation period in TOGA COARE.

• Paper: Redelsperger, J. L., P.R.A. Brown, F. Guichard, C. Hoff, M. Kawasima, S. Lang, Th. Montmerle, K. Nakamura, K. Saito, C. Seman, W.K. Tao, and L.J. Donner., 2000: A GCSS model intercomparison for a tropical squall line observed during TOGA-COARE. I: Cloud-resolving models. Quart. J. Roy. Meteor.Soc.,126, 823-864.
• Leader: Jean-Luc Redelsperger

EUROCS (EUROpean Cloud Systems):

EUROCS aim was to improve the treatment of cloud systems in global and regional climate models. EUROCS concentrated its efforts on four major and well identified deficiencies of climate models: i) stratocumulus over ocean, ii) diurnal cycle of cumulus, iii) diurnal cycle of precipitating deep convection over continents, and iv) sensitivity of deep convection development to the moisture profile. The last two areas (diurnal cycle of deep convection, led by Francoise Guichard and Jon Petch, and sensitivity of deep convection to the moisture profile, led by Stephen Derbyshire) were part of WG4 activities.

See the EUROCS web page for case descriptions and results.