According to a new study, without sea spray, hurricane-force winds wouldn’t exist. The spray kicked up by large waves and falling raindrops lubricates the air above the ocean, which decreases the amount of turbulence. This lack of turbulence allows the winds to increase in force until they become a hurricane. Researchers estimate that wind speeds would peak around 25mph if there were turbulence to sap the budding hurricane’s energy.
The equations, when applied to a cloud of water droplets sandwiched between flowing air and water, indicate that large water droplets thrown up by cresting waves in rough seas inhibit the turbulence in the air over the ocean. Without this turbulence to drain energy from the swirling winds, winds can build to tremendous speeds. Without turbulence, friction between the air and water would be reduced by a factor of 1,000, Chorin said, sometimes allowing winds to rise to speeds eight times greater than would be the case with turbulence.
The turbulent vortices in the air are suppressed by the droplets when they rain back into the sea, somewhat like “combing unruly hair,” Chorin said. These droplets are about 20 microns across (8 ten-thousandths of an inch) or larger.
The smaller the droplets, the less ability they have to suppress the turbulence, he said, which suggests one way to calm hurricanes.
Not as crazy as it might sound at first, Chorin points to ancient times when sailors used to carry oil to pour on the ocean to help calm the waves, which isn’t superstition as it turns out. (I would question its effectiveness, though. How much oil would you need to calm a storm on the Mediterranean or Aegean, even in just a small area?)
Whereas [Sir M. James] Lighthill thought that evaporation of the droplets cooled the atmosphere and led to accelerated winds, Chorin, Barenblatt and Prostokishin have showed that more important is the reduction of turbulence by falling droplets. Nevertheless, they note that evaporative cooling also serves to reduce turbulence and thus allow winds to build.
Somehow I think it’s only a matter of time before someone trademarks “Hurricane” brand sex jelly.
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