Atmospher Sci & Global Chg
Research Highlights

May 2011

A Shared Approach for Climate Insight

Presenting the aerosol research community a common modeling testbed

The Aerosol Modeling Testbed (AMT) provides the global modeling community with a way to systematically and objectively evaluate aerosol process modules to quantify uncertainties and improve global climate models. Enlarge Image

Results: Tiny bits of atmospheric dust and particles called aerosols may play a big role in global climate change, but just how big a role is not well understood. To systematically and objectively evaluate aerosol research data, scientists at Pacific Northwest National Laboratory have developed a new modeling tool, the Aerosol Modeling Testbed (AMT). Presented in the March 2011 edition of the journal Bulletin of the American Meteorological Society, AMT is offered at no charge to the research community. The tool is designed to improve our fundamental understanding of aerosols and their impact on climate change.

Why it matters: Atmospheric aerosols represent the greatest unknown in global climate change research. Consequently, the research community is using different models, different data sets, and different configurations that, when projected in global climate models, become impossible to handle computationally.

"If we pursue the same path we are on today, we will eventually arrive at a better understanding of the science, but it will be too late," said Dr. Jerome Fast, a scientist with PNNL's Aerosol Climate Initiative. "Aerosol modeling today is very haphazard; there is not a lot of systematic testing and evaluation of new aerosol process modules. We have to produce climate change models much more quickly than we are doing now. We can research ad infinitum, but our job is to understand the science and advise policy makers on corrective measures."

The Aerosol Modeling Testbed is a new tool that streamlines the process of testing and evaluating aerosol and clouds process modules based on common benchmarks and testbed cases.

Methods: PNNL scientists evaluated best practices and developed the Aerosol Modeling Testbed to be objective, systematic, and easy to use. AMT consists of a fully coupled meteorological-chemical-aerosol model and a suite of tools. As a package, it evaluates the performance of aerosol process modules across a wide range of field measurements. With objective and systematic evaluation, the performance of new approaches can be quantified and compared to existing approaches before they are incorporated into regional and global climate models.

"As more of our colleagues use this modeling testbed, there will be greater benchmark consistency in studies across different regions, across different time periods and different seasons," said Fast.

What's next: PNNL scientists are using the AMT as part of their Department of Energy Atmospheric System Research and Earth System Modeling research, and they are collaborating with university scientists to apply the AMT in regional studies. Multiple field campaign datasets are being incorporated, part of the research team's goal of broadening the AMT's use throughout the aerosol research community. Ultimately, according to Fast, as more scientists integrate regional climate models using AMT, their data and studies will become more meaningful on a global level.

Acknowledgments: This work was supported by PNNL's Laboratory Directed Research and Development program through the Aerosol Climate Initiative.

Reference: Fast, JD, WI Gustafson Jr., EG Chapman, RC Easter, JP Rishel, RA Zaveri, GA Grell, and MC Barth. 2011. "The Aerosol Modeling Testbed: A Community Tool to Objectively Evaluate Aerosol Process Modules," Bulletin of the American Meteorological Society, 92, 343-360. DOI: 10.1175/2010BAMS2868.1