August 27, 2018
Feature

Mission Possible: Estimating Cloud Area from Sky Images

A new method provides a previously unavailable data set that could help improve the representation of shifty shallow cumulus clouds in atmospheric models

clouds

Complex land-atmosphere interactions, such as the exchange of water and energy, often involve clouds and the combination of their size and shape—or cloud equivalent diameters. 

The Science

Complex interactions between Earth's surface and the atmosphere, such as the exchange of water and energy, often involve clouds and the combination of their size and shape—or cloud equivalent diameters. When it comes to shallow cumuli—puffy, cotton ball-like clouds with rapidly evolving cloud equivalent diameters—available ground-based and satellite sensors fall short of capturing these changes at the level of detail required to assess and improve the representation of shallow cumuli in atmospheric models.

Researchers from the U.S. Department of Energy's (DOE) Pacific Northwest National Laboratory, Lewis & Clark College, and the Cooperative Institute for Research in Environmental Sciences at the University of Colorado, Boulder, teamed up to develop a method for obtaining the required information on cloud equivalent diameter with high time resolution. They introduced a simple, computationally inexpensive method using low-cost, ground-based sky images.

The Impact

The new method provides a previously unavailable data set for process studies of the convective boundary layer and for evaluation of shallow cumuli growth, maturation, and dissipation in cloud-resolving models. Because many atmospheric research sites worldwide deploy low-cost, ground-based sky imagers, the research team plans to apply the new method to existing and future studies at different locations.

 

Reference: J.M. Kleiss, E.A. Riley, C.N. Long, L.D. Riihimaki, L.K. Berg, V.R. Morris, E. Kassianov, "Cloud Area Distributions of Shallow Cumuli: A New Method for Ground-Based Images." Atmosphere 9(7), 258 (2018). [https://doi.org/10.3390/atmos9070258]

Key Capabilities

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About PNNL

Pacific Northwest National Laboratory draws on its distinguishing strengths in chemistry, Earth sciences, biology and data science to advance scientific knowledge and address challenges in sustainable energy and national security. Founded in 1965, PNNL is operated by Battelle for the Department of Energy’s Office of Science, which is the single largest supporter of basic research in the physical sciences in the United States. DOE’s Office of Science is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science. For more information on PNNL, visit PNNL's News Center. Follow us on Twitter, Facebook, LinkedIn and Instagram.

Published: August 27, 2018

Research Team

Jessica M. Kleiss and Erin A. Riley, Lewis & Clark College
Charles N. Long, Cooperative Institute for Research in Environmental Sciences
Laura D. Riihimaki, Larry K. Berg, Victor R. Morris, and Evgueni Kassianov, PNNL