A Caltech Library Service

Assessing Biases and Climate Implications of the Diurnal Precipitation Cycle in Climate Models

Christopoulos, Costa and Schneider, Tapio (2021) Assessing Biases and Climate Implications of the Diurnal Precipitation Cycle in Climate Models. Geophysical Research Letters, 48 (13). Art. No. e2021GL093017. ISSN 0094-8276. doi:10.1029/2021gl093017.

[img] PDF - Published Version
See Usage Policy.

[img] PDF - Supplemental Material
See Usage Policy.


Use this Persistent URL to link to this item:


The diurnal cycle is a common benchmark for evaluating the performance of weather and climate models on short timescales. For decades, capturing the timing of peak precipitation during the day has remained a challenge for climate models. In this study, the phase and amplitude of the diurnal precipitation cycle in Coupled Model Intercomparison Project (CMIP) models are compared to satellite data. While some improvements align CMIP6 models closer to satellite observations, significant biases in the timing of peak precipitation remain, especially over land. Notably, precipitation over land in CMIP6 models still occurs ∼5.4 h too early; the diurnal cycle amplitude is ∼0.81 mm day⁻¹ too small over the oceans. Further, the diurnal phase of oceanic precipitation correlates weakly with the equilibrium climate sensitivity in CMIP6 models: models with a later precipitation peak over oceans tend to exhibit a higher climate sensitivity. However, it is unclear whether this relationship is robust.

Item Type:Article
Related URLs:
URLURL TypeDescription ItemCMIP5 model output ItemCMIP6 model output ItemIMERG data ItemGLDAS land mask
Christopoulos, Costa0000-0002-8552-465X
Schneider, Tapio0000-0001-5687-2287
Additional Information:© 2021 American Geophysical Union. Issue Online: 05 July 2021; Version of Record online: 05 July 2021; Accepted manuscript online: 26 June 2021; Manuscript accepted: 16 June 2021; Manuscript revised: 30 April 2021; Manuscript received: 17 February 2021. This work was supported by the generosity of Eric and Wendy Schmidt by recommendation of the Schmidt Futures program. The authors also acknowledge the World Climate Research Programme, which coordinated and promoted CMIP through its Working Group on Coupled Modeling. We thank the climate modeling groups for producing and making available their model output, the Earth System Grid Federation (ESGF) for archiving the data and providing access, and the multiple funding agencies who support CMIP and ESGF. Data Availability Statement: The CMIP5 and CMIP6 model output used for this study was made available by the Earth System Grid Federation (ESGF). The CMIP5 model output is available at CMIP6 at IMERG data for this study was downloaded from NASA's GES DISC FTP server ( The GLDAS land mask is available at
Funding AgencyGrant Number
Schmidt Futures ProgramUNSPECIFIED
Issue or Number:13
Record Number:CaltechAUTHORS:20210630-202305416
Persistent URL:
Official Citation:Christopoulos, C., & Schneider, T. (2021). Assessing biases and climate implications of the diurnal precipitation cycle in climate models. Geophysical Research Letters, 48, e2021GL093017.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:109681
Deposited By: Tony Diaz
Deposited On:30 Jun 2021 22:48
Last Modified:02 Feb 2022 18:41

Repository Staff Only: item control page