Precipitation Response to Mesoscale SST Variability: Insights From Observations and Multi-Resolution Models

Mesoscale sea surface temperature (SST) variability influences the marine atmosphere boundary layer (MABL), affecting near-surface winds and turbulent heat fluxes. This study examines precipitation response to mesoscale SST forcing using satellite observations, ERA5 reanalysis, and high- and low-resolution climate models. The results show that high-resolution models produce a precipitation response to mesoscale SST consistent with satellite observations and ERA5. However, partitioning ERA5 and model precipitation into resolved and parameterized convective components reveals that even in high-resolution models, the simulated mesoscale SST-precipitation relationship is shaped by the characteristics of convective parameterization. Further, the precipitation response to SST is strongly dependent on the background SST and SST variability in coupled models. Further analysis of ERA5 and high-resolution simulations shows a vertical velocity response extending to 500 hPa. However, the reliance on convective parameterizations introduces uncertainties about whether high-resolution models accurately capture these effects.