The Kain-Fritsch convection scheme and ECMWF prognostic cloud scheme: Their Jacobians and linearization properties
Luc Fillion
Meteorological Service of Canada
Abstract:
In order to efficiently assimilate satellite information over cloudy regions (e.g. rain, liquid/ice water, cloud distribution),
it is especially useful to examine the sensitivities of forecast model representations of these quantities. Moist-convective
parameterization schemes and prognostic cloud schemes thus need to be carefully examined in terms of their sensitivities (Jacobians).
This is particularly important in the context of variational data assimilation. We present results of such studies with the
Kain-Fritsch (KF) moist convective parameterization (planned to be operational at the Canadian Meteorological Center (CMC) in the coming year).
The degree of validity of the tangent-linear approximation of the KF scheme will be presented. Jacobians of the prognostic cloud scheme
currently in operations at the European Centre for Medium Range Weather Forecasts (ECMWF) will also be discussed in details.