Dynamics and oceanic response of the Madeira tip‐jets

Title: Dynamics and oceanic response of the Madeira tip‐jets

Authors: José M.R. Alves, Rui M.A. Caldeira, Pedro M.A. Miranda

Journal: Quarterly Journal of the Royal Meteorological Society

URL: https://doi.org/10.1002/qj.3825

Northeasterly trade winds impinging on Madeira island in summer are strongly diverted around the island flanks, along its west and east tips, and accelerate to sustain two moderate jet flows peaking around 200m above the ocean surface. Both jets experience strong intra-seasonal variability at the multi-week time scale, leading to oscillations in the wind direction and speed of each jet. The jets dominate the atmosphere forcing over the upper ocean, leading to enhanced mixing with potential impact on the transport of organisms, pollutant dispersion, and on the trajectories of suspended matter. We have known for some time that tip jets may be triggered by traveling storms near the edges of Greenland, driving ocean convection. Under weaker but sustained winds, such as those found in the subtropical trade wind system, tip jets are here found to also play an important role, intensifying atmosphere-ocean fluxes, and extending the influence of an isolated island to a broader region.