By Kimberly Miller From Palm beach Post

A University of Miami study found that fresh water plumes dumped into the Caribbean Sea may be helping hurricanes intensify rapidly along a path often taken by tropical cyclones, including October’s Hurricane Matthew.

This brackish sluice over the saltier sea — like oil on water — may be helping hurricanes rapidly intensify by blocking access to power-restraining cooler waters below, according to a University of Miami study published in the Journal of Geophysical Research.

Warm eddys already swirl in the Caribbean, providing bursts of energy for burgeoning storms, but the freshwater overlay — called a barrier layer in the UM paper — could be acting as an amplifier.

“As a hurricane passes, it brings that cooler water up from deeper down, but the unique part about the barrier layer is it reduces the efficiency of bringing that cooler water to the surface,” said Johna Rudzin, a Ph.D. student at UM’s Rosenstiel School of Marine and Atmospheric Science and the lead author on the study. “When the hurricane tries to mix the upper ocean, it would be much more difficult because of the freshwater input.”

Rudzin’s study began two years ago when a research team from UM’s Upper Ocean Dynamics Laboratory dropped 55 sensors in the Caribbean Sea to measure ocean temperature, salinity and currents. The goal was to better understand the characteristics of the Caribbean’s warm-water eddies, which likely originate from the North Brazil Current.

While warm ocean eddies in the Gulf of Mexico are well–identified, Rudzin said she was surprised by a lack of research targeting upper-ocean warm eddies in the Caribbean.

“That’s kind of troublesome, knowing that lots of hurricanes pass through that region,” she said.

Hurricane Matthew grew to a dangerous Category 5 storm with 160 mph winds in this region, gaining 80 mph in 24 hours.

IMAGE: Hurricane Matthew over the Bahamas in October 2016.

For more on this story go to: http://weatherplus.blog.palmbeachpost.com/2017/03/06/how-the-amazon-river-may-make-hurricanes-more-deadly/