An evaluation of the seasonal Caribbean hydroclimate in low and high-resolution CESM and other CMIP6 models
Martinez, C. J., Simpson, I. R., Fasullo, J. T., Prein, A.. (2025). An evaluation of the seasonal Caribbean hydroclimate in low and high-resolution CESM and other CMIP6 models. Climate Dynamics, doi:https://doi.org/10.1007/s00382-024-07516-4
| Title | An evaluation of the seasonal Caribbean hydroclimate in low and high-resolution CESM and other CMIP6 models |
|---|---|
| Genre | Article |
| Author(s) | Carlos J. Martinez, Isla R. Simpson, John T. Fasullo, Andreas Prein |
| Abstract | The Caribbean and Central American hydroclimate is understudied and complex in part due to its data sparsity, varied topographies, and multi-faceted interactions with the tropics and mid-latitudes. Recent work developed a refined and comprehensive understanding of the observed hydroclimate that has yet to be explored in global circulation models. This study investigates the simulation of the Caribbean hydroclimate using a suite of station and gridded observational datasets, the Community Earth System Model version 1 (CESM1) at high (0.25 × 0.25°) and low (0.9 × 1.25°) resolution, CESM2 at low (0.9 × 1.25°) resolution, the Coupled Model Intercomparison Project phase 6 (CMIP6) High-Resolution Model Intercomparison Project (HighResMIP), and the Geophysical Fluid Dynamics Laboratory Seamless System for Prediction and Earth System Research (GFDL-SPEAR). The simulated climatologies (1983–2014) of the annual rainfall cycle and total moisture fluxes, and climatological regressions of sea surface temperatures (SST), sea-level pressure (SLP), and zonal/meridional low-level winds onto indices of seasonal Caribbean rainfall totals are calculated to investigate inter-model differences and their comparison to observations. Generally, fully coupled CESM, GFDL-SPEAR-MED, and CMIP6 simulations underestimate precipitation across the Caribbean, with some improvements using high-resolution (< 0.5°) simulations. The underestimations are largest during the Early-Rainy Season (ERS; mid-April to mid-June). Coupled models also show a moisture divergence bias associated with a stronger/west-displaced North Atlantic Subtropical High (NASH), a weaker / southward displaced Intertropical Convergence Zone (ITCZ), and stronger Caribbean Low-Level Jet (CLLJ). Precipitation and large-scale dynamic biases in experiments with observation-based SSTs are smaller, regardless of their spatial resolution, suggesting SST biases in coupled models may contribute to precipitation and circulation biases. The findings emphasize the importance of both high-resolution and accurate simulation of coupled dynamical interactions in global circulation models to accurately simulate the Caribbean’s hydroclimate, and, therefore, provide reliable future climate projections for the region. |
| Publication Title | Climate Dynamics |
| Publication Date | Jan 1, 2025 |
| Publisher's Version of Record | https://doi.org/10.1007/s00382-024-07516-4 |
| OpenSky Citable URL | https://n2t.net/ark:/85065/d7g73k2z |
| OpenSky Listing | View on OpenSky |
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