The Influence of Ocean Coupling on Simulated and Projected Tropical
Cyclone Precipitation in the HighResMIP-PRIMAVERA Simulations
Abstract
This study aims to quantify the impacts of ocean coupling on simulated
and projected tropical cyclone (TC) precipitationin the Northern
Hemisphere. We used global climate model (GCM) simulations over
1950-2050 from the High Resolution Model Intercomparison Project
(HighResMIP) and compared its fully coupled atmosphere-ocean GCMs
(AOGCMs) with atmosphere-only GCMs (AGCMs). We find that ocean coupling
generally leads to decreased TC precipitation over ocean and land.
Large-scale sea surface temperature (SST) biases are critical drivers of
the precipitation difference, with secondary contributions from local
TC-ocean feedbacks via SST cold wakes. The two driving factors,
attributed to ocean coupling in the AOGCMs, influence TC precipitation
in association with decreased TC intensity and specific humidity. The
AOGCMs and AGCMs consistently project TC precipitation increases in
2015-2050 relative to 1950-2014 over ocean for all basins, and for
landfalling TCs in the North Atlantic and western North Pacific.