NASA Cloud Modeling and Analysis Initiative (CMAI)


CMAI: Participants | Meetings | Draft Workplan | Investigations

Representation of clouds and cloud processes in climate and weather models (particularly in NASA-supported models) is considered one of the central issues driving uncertainty about their fidelity in making forecasts. NASA's research goal is to use satellite observations to extend our understanding of clouds in climate and weather to global scale and to evaluate cloud process, weather and climate model representations of cloud processes. The launch of CALIPSO and CloudSat in May 2006 into a co-orbiting constellation including Aqua, Aura and Parasol and the combination of these satellites with TRMM and the weather satellite constellation has created an unprecedented grouping of satellite sensors, covering UV to microwave wavelengths, for the observation and study of cloud properties and behavior. NASA is funding research to focus on analysis and modeling of integrated datasets from this constellation of satellites. Critical topics that the CMAI seeks to address include:

(1) Cloud formation processes: quantify the mass flow rate of vapor-to-condensate for liquid clouds and for ice clouds (including freezing and supersaturation effects).
(2) Precipitation formation processes: quantify the mass flow rate of cloud condensate to precipitation form (collisional growth process), both rain and snow.
(3) Cloud lifecycle dynamics: quantify the scale dependence of the coupling of atmospheric dynamics with radiation and precipitation by clouds necessary to generalize findings so that they can be accurately and effectively represented in climate (Earth System) and weather models.
(4) Orographic effects: similar to (3) but with a particular focus on quantifying the effects of orography on cloud-precipitation behavior.
(5) In (1)-(3) above, how does the presence of a changing aerosol environment influence cloud and precipitation behavior?

To facilitate the synthesis of field and satellite observations and cloud-resolving and global models outputs, funded proposers will be expected to contribute to the augmentation of an enhanced version of the GEWEX Cloud System Study Data Integration for Model Evaluation (GCSS-DIME) Web site ( in one or more of the following ways:

(1) providing either a hyperlink to a Web site containing an assembled collection of field datasets employed in the investigator's own study or providing the datasets themselves,
(2) providing "cloud object" statistical results (e.g., composites, multi-dimensional histograms) and/or the software tools for producing them from global long-term satellite observations and global model output,
(3) providing statistics from large ensembles of cloud-resolving model runs that can be used to develop and test 3-D radiation schemes and cloud-precipitation parameterizations, and
(4) providing statistics relating the general circulation to cloud property distributions and quantifying how these relations change with changing weather states or with changing climate in GCM ensembles.

This section of the DIME website will present materials developed by NASA-funded investigations into cloud processes, including observational syntheses and model study results that support their findings.

CMAI: Participants | Meetings | Draft Workplan | Investigations