Atmospheric Sciences & Global Change
Uncovering Global Effects of Clouds on Climate
Multi-scale model provides global view of Asian pollution impacts on Pacific storm track
The Pacific storm track affects weather and climate around the world. The simulation image is courtesy of NOAA’s Geophysical Fluid Dynamics Laboratory. Enlarge Image.
Results: Scientists from Texas A&M University and Pacific Northwest National Laboratory provided a first-time global perspective of the impacts of Asian pollution on the Pacific storm track and subsequent weather. They found that a unique modeling technique allowed them to understand the global scale effect of tiny pollution particles to strengthen storm clouds and rain. Developed at PNNL, the technique is essential to revealing the small-scale effects of clouds in a large-scale model. The study, published in the Proceedings of the National Academy of Sciences (PNAS), was reported in the online Early Edition April 14.
"The higher resolution improved the cloud simulations," said Dr. Minghuai Wang, PNNL climate scientist. "Conventional global scale models usually show a decrease in precipitation in response to man-made aerosols, but we see the increase that we know happens in real life."
Why It Matters: Man-made pollution particles, also called aerosols, can affect the climate by altering cloud formations. Until now, their effects on storm cloud systems were either missing or crudely represented in global models used to understand climate trends or possible future climate scenarios. This research allows a way to include the aerosol effects on storm cloud systems—the small-scale details—in global models that are at large-scale resolutions.
Methods: In this study, the researchers used a multi-scale global aerosol-climate model that embeds a two-dimensional cloud-resolving model, explicitly simulating aerosol effects on deep clouds to examine aerosol effects on the Pacific storm track. They compared results from the multi-scale aerosol-climate model to a conventional aerosol-climate model and showed that increased activity in the Pacific storm track is due to man-made aerosol particles. Unlike conventional climate model results without the cloud-resolving detail, their findings are consistent with observations.
For more, see PNNL news release, "Researchers reconstruct Pacific storm track in climate model"
What's Next? The researchers will expand the unique capability of the multi-scale aerosol-climate model to examine aerosol effects on hydrological cycles, such as the Asia monsoon.
Sponsors: The research was supported by a NASA Graduate Student Fellowship in Earth System Science; the Ministry of Science and Technology of China; the NASA Research Opportunities in Space and Earth Sciences, Enhancing the Capabilities of Computational Earth System Models and NASA Data for Operation and Assessment program at the Jet Propulsion Laboratory, California Institute of Technology; and the U.S. Department of Energy (DOE) Office of Science Biological & Environmental Research's Earth System Modeling and Regional & Global Climate Modeling programs for the Decadal and Regional Climate Prediction using Earth System Models (EaSM) project. This research used computing resources at the Oak Ridge Leadership Computing Facility, supported by DOE's Office of Science.
Research Team: Minghuai Wang and Steve Ghan, PNNL; Yuan Wang, Renyi Zhang, Yun Lin, Jiaxi Hu, Bowen Pan and Misti Levy, Texas A&M University; Jonathan H. Jiang, Jet Propulsion Laboratory, California Institute of Technology; and Mario J. Molina, University of California San Diego.
Research Area: Climate & Earth Systems Science
Reference: Wang Y, M Wang, R Zhang, S Ghan, Y Lin, J Hu, B Pan, M Levy, J Jiang, M Molina. 2014. "Assessing the impact of anthropogenic aerosols on Pacific storm track using a multi-scale global climate model." Proceedings of the National Academy of Sciences, early online. DOI: 10.1073/pnas.1403364111