Climate models are sophisticated numerical tools used to estimate and explore what Earth’s climate was like in the past, how it behaves now, and how it will change in the future.
Many studies combine results from multiple climate models to calculate average estimates and measure the spread of model predictions of temperature, precipitation, and other characteristics of the Earth system. However, many climate models share features of their underlying computer codes and other properties, so giving equal weight to all models included in a multimodel study may result in some codes being over-represented or under-represented, which may bias the study results.
To help researchers more accurately account for the relationship between climate models, Peter Kuma and colleagues created a genealogy based on computer code of 167 models, 114 of which are part of Coupled Model Intercomparison Project (CMIP) Phases 3, 5, and 6. These models all simulate many components of the Earth’s climate system, such as atmospheric, oceanic, and biological processes. Because atmospheric physics, particularly the description of cloud processes, is believed to contribute to most of the uncertainties associated with climate sensitivity, the researchers focused their analysis on the atmospheric physics components of the 167 models.
The analysis identified 12 main groups, or families, of climate models. Within each family, the model codes share a common heritage and tend to produce similar estimates of important climate properties.
Based on these climate model “family trees,” the researchers propose statistical methods that can be used in future multimodel studies to better account for code relationships among different models and reduce the biases of the study results. They also suggest that as more models are developed, these models can be added to add new genealogy.
Peter Kuma et al, Climate Model Code Genealogy and Its Relationship to Climate Feedbacks and Sensitivity, Journal of Advances in Earth System Modeling (2023). DOI: 10.1029/2022MS003588
Provided by the American Geophysical Union
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Citation: Family trees explain relationships in climate models (2023, July 18) retrieved on 18 July 2023 from https://phys.org/news/2023-07-family-trees-relationships -climate.html
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