Love, P. K., A. Henderson-Sellers and P. Irannejad, 1995:
AMIP diagnostic subproject 12 (PILPS Phase 3): Land surface processes.
Abstracts of the First International AMIP Scientific Conference, Monterey,
California, 29.
Diagnostic subproject 12 is analysing models that use, or have as an
alternative, a landsurface scheme that is participating in the GEWEX Project
for Intercomparison of Landsurface Parameterization Schemes (PILPS). Completed
large scale analysis has identified intermodel consistencies, differences
and trends, and areas of interest for regional investigation. It is found
that no one model is representative of all of the models over all fields
and no one model is an outlier over all fields. Seasonal and zonal behaviours
are similar but two models show significant spin-up over the first two
years. The forcing from the sea surface temperatures is apparent in the
continental climates and two maxima corresponding to the 1982-83 and 1987-88
El Niño-Southern Oscillation events are particularly distinct. One
model has anomalously high SSTs and this propagates to the results over
the land. Cloud cover does not show consistent enough behaviour to indicate
that it is simply related to surface radiation or precipitation. The Bowen
ratio shows intermodel differences that are not simply related to landsurface
scheme complexity. Three models have significant globally averaged surface
energy residuals. Two have globally and annually averaged values of about
5 to 6 Wpm2 and one a value of about 13 Wpm2. The importance of model initialisation
is very clear in some models where ten year trends in soil moisture are
closely related to ten year trends in temperature. Regional analysis using
areas around the PILPS tropical rainforest and tundra points show ranges
of sensible and latent heats similar to those seen in the PILPS Phase 1
off-line experiments. Differences between the sensible/latent heat partitioning
found here and in PILPS are shown to be consistent with differences in
precipitation. Many models show large surface energy residuals at individual
grid points.