CLOUDGEN

Robin Hogan <[email protected]>
Version 1.1  10 Nov 2003
Version 1.2  25 May 2005
Version 1.3   9 May 2006

This directory contains the "cloudgen" code, for producing stochastic
3D cirrus clouds with realistic horizontal and vertical structure.

It is licensed under the GNU General Public License - see COPYING.

To compile you first need to install version 2 of the FFTW library,
available from www.fftw.org and the netcdf library, available from
https://www.unidata.ucar.edu/software/netcdf/.  Cloudgen will be faster but
sill sufficiently accurate if you use FFTW compiled with single rather
than double precision.

Once these libraries are installed, just type "make".  You may have to
edit the Makefile for your system.  Cloudgen is written in ANSI C and
has been tested on Linux.

To get started, have a look at "cirrus.dat" and README files in the
samples directory.  Running "cloudgen" on cirrus.dat will produce a
netcdf file "iwc.nc" containing an idealised 3D stochastic cirrus
cloud field. More realistic cases derived from observations by the
Chilbolton 94-GHz "Galileo" radar are also present in the samples
directory, as well as an idealised stratocumulus case.

To understand how the algorithm works, I suggest you read Hogan and
Kew (2005) below. If you use the algorithm in a publication then this
paper should be cited. If you also make use of the cases derived from
the Galileo radar (the samples/1999*.dat files) then you should
include an acknowledgement along the lines of "the input parameters to
the stochastic model were calculated by Robin Hogan using observations
from the 94-GHz Galileo cloud radar at Chilbolton, which is operated
by the Rutherford Appleton Laboratory".

References:

Hogan, R. J., and S. F. Kew., 2005: A 3D stochastic cloud
model for investigating the radiative properties of inhomogeneous
cirrus clouds.  Q. J. R. Meteorol. Soc., 131, 2585-2608.
Available from www.met.rdg.ac.uk/clouds/publications.html

Hogan, R. J., and S. F. Kew, 2004: A 3D stochastic cloud model for
investigating the radiative properties of inhomogeneous cirrus clouds.
Proc. 14th Int. Conf. on Clouds and Precipitation, Bologna, Italy,
1669-1672.
Available from www.met.rdg.ac.uk/clouds/conference_papers.html

Kew, Sarah F., 2003: Development of a 3D fractal cirrus model and its
use in investigating the impact of cirrus inhomogeneity on
radiation. MSc Dissertation, Department of Mathematics, University of
Reading.
Available from www.extra.rdg.ac.uk/Maths/Research/Publications/MSc_dissertations.asp