Evaluation of historical precipitation interannual variability in CMIP6 over the United States

Interannual precipitation variability profoundly influences society via its effects on agriculture, water resources, infrastructure, and disaster risks. In this study, we use daily in situ precipitation observations from the global historical climatology network-daily (GHCN-D) to assess the ability...

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Main Authors: Ryan D Harp, Thierry N Taguela, Akintomide A Akinsanola, Daniel E Horton
Format: Article
Language:English
Published: IOP Publishing 2025-01-01
Series:Environmental Research: Climate
Subjects:
Online Access:https://doi.org/10.1088/2752-5295/ada17c
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author Ryan D Harp
Thierry N Taguela
Akintomide A Akinsanola
Daniel E Horton
author_facet Ryan D Harp
Thierry N Taguela
Akintomide A Akinsanola
Daniel E Horton
author_sort Ryan D Harp
collection DOAJ
description Interannual precipitation variability profoundly influences society via its effects on agriculture, water resources, infrastructure, and disaster risks. In this study, we use daily in situ precipitation observations from the global historical climatology network-daily (GHCN-D) to assess the ability of 21 Coupled Model Intercomparison Project Phase 6 (CMIP6) models, including the 50-member fifth-generation Canadian Earth System Model single model initial-condition large ensemble (CanESM5_SMILE), to realistically simulate historical interannual precipitation variability trends within 17 regions of the contiguous United States (CONUS). We assess how accurately the CMIP6 simulations align with observational data across annual, summer, and winter periods, focusing on four key hydrometeorological metrics, including interannual precipitation variability, relative interannual precipitation variability (coefficient of variation), annual mean precipitation, and annual wet day frequency. Our findings reveal that CMIP6 ensemble members generally reproduce the spatial patterns of observed trends in annual mean precipitation. In most regions, models agree well with the signs of observed changes in annual mean precipitation, though discrepancies in trend magnitude are evident. Further, observed trends in winter mean precipitation broadly exhibit a spatial pattern similar to that of the observed annual mean. However, analysis of the CanESM5_SMILE shows that trends in precipitation variability may primarily be the result of model-simulated internal variability, suggesting caution in interpreting multi-model single-realization ensemble results. Challenges in accurately simulating interannual precipitation variability underscore the need for ongoing model refinement and validation to enhance climate projections, especially in regions vulnerable to extreme precipitation events.
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spelling doaj-art-4f9776b821e64189b6c523a77a372e512025-01-02T16:20:35ZengIOP PublishingEnvironmental Research: Climate2752-52952025-01-013404503210.1088/2752-5295/ada17cEvaluation of historical precipitation interannual variability in CMIP6 over the United StatesRyan D Harp0https://orcid.org/0000-0002-2872-8541Thierry N Taguela1https://orcid.org/0000-0001-8140-125XAkintomide A Akinsanola2https://orcid.org/0000-0002-0192-0082Daniel E Horton3https://orcid.org/0000-0002-2065-4517Department of Earth, Environmental, and Planetary Sciences, Northwestern University , Evanston, IL, United States of AmericaDepartment of Earth and Environmental Sciences, University of Illinois Chicago , Chicago, IL, United States of AmericaDepartment of Earth and Environmental Sciences, University of Illinois Chicago , Chicago, IL, United States of America; Environmental Science Division, Argonne National Laboratory , Lemont, IL, United States of AmericaDepartment of Earth, Environmental, and Planetary Sciences, Northwestern University , Evanston, IL, United States of AmericaInterannual precipitation variability profoundly influences society via its effects on agriculture, water resources, infrastructure, and disaster risks. In this study, we use daily in situ precipitation observations from the global historical climatology network-daily (GHCN-D) to assess the ability of 21 Coupled Model Intercomparison Project Phase 6 (CMIP6) models, including the 50-member fifth-generation Canadian Earth System Model single model initial-condition large ensemble (CanESM5_SMILE), to realistically simulate historical interannual precipitation variability trends within 17 regions of the contiguous United States (CONUS). We assess how accurately the CMIP6 simulations align with observational data across annual, summer, and winter periods, focusing on four key hydrometeorological metrics, including interannual precipitation variability, relative interannual precipitation variability (coefficient of variation), annual mean precipitation, and annual wet day frequency. Our findings reveal that CMIP6 ensemble members generally reproduce the spatial patterns of observed trends in annual mean precipitation. In most regions, models agree well with the signs of observed changes in annual mean precipitation, though discrepancies in trend magnitude are evident. Further, observed trends in winter mean precipitation broadly exhibit a spatial pattern similar to that of the observed annual mean. However, analysis of the CanESM5_SMILE shows that trends in precipitation variability may primarily be the result of model-simulated internal variability, suggesting caution in interpreting multi-model single-realization ensemble results. Challenges in accurately simulating interannual precipitation variability underscore the need for ongoing model refinement and validation to enhance climate projections, especially in regions vulnerable to extreme precipitation events.https://doi.org/10.1088/2752-5295/ada17cUnited Statesprecipitationinterannual variabilityCMIP6 modelsinternal variability
spellingShingle Ryan D Harp
Thierry N Taguela
Akintomide A Akinsanola
Daniel E Horton
Evaluation of historical precipitation interannual variability in CMIP6 over the United States
Environmental Research: Climate
United States
precipitation
interannual variability
CMIP6 models
internal variability
title Evaluation of historical precipitation interannual variability in CMIP6 over the United States
title_full Evaluation of historical precipitation interannual variability in CMIP6 over the United States
title_fullStr Evaluation of historical precipitation interannual variability in CMIP6 over the United States
title_full_unstemmed Evaluation of historical precipitation interannual variability in CMIP6 over the United States
title_short Evaluation of historical precipitation interannual variability in CMIP6 over the United States
title_sort evaluation of historical precipitation interannual variability in cmip6 over the united states
topic United States
precipitation
interannual variability
CMIP6 models
internal variability
url https://doi.org/10.1088/2752-5295/ada17c
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AT akintomideaakinsanola evaluationofhistoricalprecipitationinterannualvariabilityincmip6overtheunitedstates
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