Case updates

Input ncdf file, 19 April 2011

The NetCDf file containing the initial profiles has been updated. It now contains the initial pressure profile at all LES levels ('pf').

Pressure, 10 March 2011

Although most of the participants have included the pressure as a function of time and height, it was missing in the list of output variables and has now been added.

Sponge layer horizontal wind velocities, 14 February 2011

The time varying wind velocities in the free atmosphere are added to the netcdf file ('ufa' and 'vfa' in These velocities can be used to nudge the velocities in the sponge layer (used in LES models).

Specification of the solar radiative forcing, 20 January 2011

The value for the solar constant S0 = 1367 Wm-2. Please use as date 13 June 1992, latitude=340N, and longitude 250W

Input ncdf file, 02 December 2010

Added the factor 1e-6 to the divergence (div) which was missing in the ncdf file. Thanks Adrian for pointing this out.

Case revision, 10 November 2010

  • The input profiles are given in the NCDF file
  • According to a suggestion by Andy Ackerman, the cloud droplet effective radius reff should be computed from the mean volume radius rvol multiplied by a factor 1.03: reff=1.03 rvol
  • Small changes in the prescribed large-scale divergence and geostrophic winds.
  • Zenith dependent sea surface albedo.
  • SST, surface albedo and radiative flux profiles added to output.
  • Radiative fluxes calculated for the initial state are asked.
  • Specification of the virtual potential temperature, 16 August 2010

    To compute the buoyancy flux, please use the following definition, θv= θ (1 + εI qvap - qliq), with θI = Rv/Rd-1 = 0.608, and Rd=287.04 J kg-1 K-1, Rv = 461.5 J kg-1 K-1, the gas constants for dry air and water vapor, respectively. The entrainment rate was missing in the requested output data and has been added.

    Input ncdf file, 1 July 2010

    Renaming levels to lev (to be consistent with Irina's composite case), and addition of the large-scale divergence as a function of time.

    SCM output, 1 July 2010

    Specification of the requested SCM output

    LES domain size, 30 June 2010

    For consistency with the composite case of Irina Sandu the horizontal grid resolution has been refined to 35 m such that with 128 grid points the horizontal domain size is 4.48x4.48 km2.

    Large-scale subsidence, 29 June 2010

    The prescribed constant large-scale divergence rate has been replaced by a time-varying one according to ERA-40 data analysed by Chris Bretherton.