What happens if a hurricane and oil spill mix?
With hurricane season under way and the beaches on the gulf coast affected by oil, is a perfect storm brewing to hurt the coast even more?
Dennis Feltgen, meteorologist with the National Hurricane Center in Miami, said forecasters do not yet understand the properties of the oil, and do not yet know what the interaction will be with a hurricane.
But there are many hypotheses that NOAA hurricane forecasters and researchers believe the interactions could be, and research and modeling will need to be done to test these assumptions, he said.
“NOAA’s Hurricane Research Division is planning to make observations and run simulations to test these hypotheses so that we can incorporate them into future hurricane forecasts,” Feltgen said. “Some of the hypotheses that need to be tested are first, will the oil slick help or hurt a storm from developing in the Gulf?”
Feltgen said evaporation from the sea surface fuels tropical storms and hurricanes, and over calm water, an oil slick can suppress evaporation if the layer is thick enough by not allowing contact of the water to the air.
“With less evaporation one might assume there would be less moisture available to fuel the hurricane and thus reduce its strength,” Feltgen said. “However, at high wind speeds, such as those found in tropical storms and hurricanes, a thin layer of oil such as is the case with the current slick (except in very limited areas near the well) would likely break into pools on the surface or mix as drops in the upper layers of the ocean, allowing much of the water to remain in touch the overlying air and greatly reduce any effect on evaporation. When that happens, the oil slick is not likely to have a significant impact on the hurricane.”
What would happen if a hurricane went through an oil slick?
“If the slick remains small in comparison to a typical hurricane’s general environment and size, as is the case today, the anticipated impact on the hurricane would be minimal,” Feltgen said. “The oil is not expected to appreciably affect either the intensity or the track of a fully developed tropical storm or hurricane. The oil slick would have little effect on the storm surge or near-shore wave heights.”
In some ways, a hurricane would help disperse the oil, Feltgen said, but it could also help drive it to the coast.
“The high winds and seas will mix and ‘weather’ the oil, which helps accelerate the biodegradation process,” he said. “The high winds may distribute oil over a wide area but it is difficult to model exactly where the oil may be transported. Storms’ surges may carry oil inland mixed with hurricane debris. Movement of oil in a hurricane would depend greatly on the track of the hurricane. A hurricane passing to the west of the oil slick could drive a large volume of oil to the coast.”