The Department of Energy has awarded Iowa State University $2 million to assess different methods of climate simulation that are important for evaluating climate change projections.
"The immediate goal is to understand how well they credibly replicate observations of the climate system," said William Gutowski, professor of geological and atmospheric sciences and associate dean of the College of Liberal Arts and Sciences. "We want to compare these different approaches side by side. We want to see where they each have their strengths and where they each have their challenges."
The assessment will aim to improve various climate models, simulations that produce climate projections for regions such as the corn belt or major river basins. Current models don’t always give the same projections and sometimes project opposite changes in a region.
The goal of understanding the reliability of the models begins with understanding how well the models replicate reality and what level of error occurs within a model. This helps clarify what changes projected by a model are meaningful.
"If we have changes that are smaller than the errors, then we have much less confidence that it’s truly a change of any kind of significance," Gutowski said. "If the changes exceed that, then that’s the starting point for saying these are the things we really need to pay attention to."
The assessment will also develop new metrics to focus on physical behaviors and properties, which would help the researchers understand if the right numbers are being produced for the right reasons and if the data makes sense.
These assessments will also look into “what if” scenarios such as changes that can be expected based on changes in how land is used over time.
Both regional and global models will be assessed for their accuracy with simple measures of credibility such as temperature values and for their accuracy with these more complex physical assessments and scenarios. Data used will primarily come from the continental United States. The goal is not to pick a single best model, but rather to understand and improve upon the strengths and challenges of each.
The funding is part of a larger grant awarded to multiple institutions including the Department of Energy Pacific Northwest National Lab, the National Center for Atmosphere Research in Boulder, Colorado, Cornell University, University of California Los Angeles, and Texas A&M.
"We’re all really partners working together," Gutowski said. "Part of what I find really attractive and exciting about this project is that the people I get to work with are people I have long enjoyed working with."