Atmospheric response to Tropical Instability Waves in high-resolution coupled NextGEMS simulations

<p>Oceanic Tropical Instability Waves (TIW) are characterized by westward propagating cusp-shaped sea surface temperature (SST) patterns with sharp fronts and strong lateral SST gradients. TIWs impact local winds and ocean atmosphere heat fluxes and these changes consequently feed back onto the ocean.<br />Previous studies have used stand-alone atmosphere or regional coupled ocean-atmosphere models at moderate to high resolution. &#160;The new global simulations, which are run at km-scale resolution in both ocean and atmosphere in the framework of the H2020 NextGEMS project, offer new opportunities to study local, regional, and remote effects of TIW-related ocean-atmosphere interactions.<br />Using the coupled ICON-a/ICON-o &#8220;Sapphire&#8221; simulations (Hohenegger et al., 2023), we compare the ocean-atmosphere coupling in the Pacific and Atlantic basin and investigate the interaction of TIWs with the Intertropical Convergence Zone.&#160;<br />In the western tropical Atlantic, north of the Equator, TIW induced SST patterns also interact with North Brazil Current eddies and we investigate the effects of pronounced fronts on ocean-atmosphere heat fluxes.</p> <p><br />Hohenegger, C. at al., 2023: ICON-Sapphire: simulating the components of the Earth System and their interactions at kilometer and subkilometer scales, Geoscientific Model Development, https://doi.org/10.5194/gmd-2022-171.</p>