About ClimGen
ClimGen is a spatial climate scenario generator, designed to allow users
to explore some of the uncertainties in future climate change at regional scales.
ClimGen was originally developed by
Tim Osborn (Climatic Research Unit, CRU)
and
Tim Mitchell (then at the Tyndall Centre for Climate Change Research),
both in the School of Environmental
Science, University of East Anglia, Norwich, UK. ClimGen is being maintained
and developed further by Tim Osborn. Other contributions (data processing, advice,
testing, etc.) have been made by Craig Wallace, Ian Harris, Tom Melvin, Nigel Arnell,
Rachel Warren, Rita Yu, Jeff Price and a number
of others.
ClimGen is based on the so-called "pattern-scaling" approach to generating
spatial climate change information for a given global-mean temperature change.
The pattern-scaling approach relies on the assumption that the pattern of climate
change (encompassing the geographical, seasonal and multi-variable structure)
simulated by coupled atmosphere-ocean general circulation models (AOGCMs) is relatively
constant (for a given AOGCM) under a range of rates and amounts of global warming,
provided that the changes are expressed as change per unit Kelvin of global-mean
temperature change. These normalised patterns of climate change do, however, show
considerable variation between different AOGCMs, and it is this variation that
ClimGen is principally designed to explore. Further scientific details are
provided in the technical paper given below.
ClimGen also provides a convenient interface for generating these scenarios
and for extracting observed climate data in a common format, with options to extract
user-defined regions, seasons and specific time periods.
In some respects, ClimGen is similar to other spatial scenario generators
that use the pattern-scaling approach, some of which are listed in the technical paper
given below. Similar tools have previously been developed at CRU/UEA -- notably SCENGEN.
Information about SCENGEN version 2.x (Wigley et al., 2000; Hulme et al., 2000)
is available here (archived copy). SCENGEN
was subsequently developed further by Tom Wigley at NCAR, Boulder, Colorado, USA, and
information about SCENGEN version 4.x (Wigley, 2003) was available
here (archived copy).
ClimGen does not re-use any of the SCENGEN software code, and only uses the
concepts from SCENGEN that are common to all tools of this type.