1. Model Uncertainties: IPCC GCMs
Model values of globally averaged Precipitation, Precipitable Water and even Cloud Fraction (above) Agree within 10-20%. These quantities have been measured by a variety of satellite and other data sources for some time.
Factor of ~20
Factor of ~6
However, model agreement for cloud ice, even total cloud ice path (left), is very poor. This quantity is fundamental to establishing a proper representation of the water and energy cycle of the atmosphere and the cloud feedback within the climate system.
This level of disagreement must be reduced. AURA/MLS & now CloudSat Are Helping
D. Waliser/JPL

2. Upper-Tropospheric Cloud Ice: MLS vs Models
January 2005 or Climatological January Values (Li et al. 2005)
MLS VALUES
GEOS-5
Above models did not have the benefit of AURA/MLS - which provides global Upper Tropospheric Cloud Ice Values. GEOS-5 (left) development did have this additional observational constraint and appears to have benefited from the new satellite-derived data.
D. Waliser/JPL

3. ECMWF Integrated Forecasting System
NASA Cloud Ice Values &
ECMWF Integrated Forecasting System
AURA/MLS, and now CloudSat, cloud ice values are being used in collaboration with ECMWF to reduce errors in their global analysis and forecast system (Li et al. 2006; See May 23, 2006 Letter).
MLS
CloudSat
ECMWF_OLD
ECMWF_NEW
The maps above show upper tropospheric cloud ice values from AURA/MLS and CloudSat, as well as from the previous operational version of the ECMWF model and the latest version (Sep 06) whose development benefited from the recent availability of NASA satellite cloud ice data.
D. Waliser/JPL
Data are all from Jul07-Aug13, ~ 14km