The study of cloud microphysics involves the use of observations and numerical modeling over a wide variety of scales: at the smallest scales (on the order of micrometers), droplet interactions are important for understanding precipitation initiation, while at the largest scales (on the orders of kilometers or larger), internal cloud motions may carry hydrometeors to parts of the cloud where their growth may be enhanced or suppressed. The cloud microphysicist must assimilate information across this huge range of scales in order to solve the most difficult problems in the field, many of which have persisted for decades. A lack of visualization tools has impeded progress on these difficult problems. While modeling and observational capabilities have improved greatly over the last several decades, the visualization of these multi-scale data bases has lagged. Unfortunately, many atmospheric scientists are limited to two-dimensional visualization tools (plots, contours) or three-dimensional tools that only allow them to look at portions of their data sets, such as isosurfaces.

Work is currently underway at Purdue University under a collaborative NSF-sponsored effort to improve the visual analysis capabilities for multi-scale atmospheric model output and observations. Such collaboration provides an example of atmospheric science students learning to work and communicate with professionals in another field of study, a valuable skill when entering the workplace. This presentation will focus upon the use of a new visualization system for a specific problem in cloud microphysics: the influence of entrainment and mixing on the cloud droplet population in trade wind cumulus clouds. The visualization tools will be used to display a three-dimensional cloud model simulation of a trade wind cumulus in tandem with microphysical calculations along trajectories produced by a Lagrangian microphysical parcel model. The analysis system allows the user to view the path traversed by each air parcel with the development of the cloud simultaneously in four-dimensions. These tools will be used to elucidate the influence of entrainment and mixing on the cloud droplet population, and to explain if entrainment and mixing can account for the increasing droplet concentration with altitude that was often observed in the trade wind cumuli during a recent field campaign.