Comment on “Oceanic Rossby Waves Acting As a ‘Hay Rake ’ for Ecosystem Floating By-Products”

Remote sensing of the sea surface has shown that Rossby waves (RWs), or plane-tary waves, are ubiquitous in the world ocean (1, 2), although the precise mechanisms for their formation and propagation are still un-der debate (3–5). Recently, similar propagat-ing signals have been observed in ocean color (6, 7). Here, too, the mechanisms remain unclear; nutrient pumping into the photic lay-er, followed by uptake by phytoplankton, has been suggested (8), as has lateral advection by the propagating RWs (7). The phase dif-ference between the color and surface-height signals serves as an excellent discriminator between mechanisms (7)