Storm’s eye could hold way to gauge intensity
MIAMI >> Hurricane forecasters might have a new tool in solving the vexing problem of understanding storm intensity: gravity waves.
Gravity waves are produced when air moving around the atmosphere gets pushed from one place to another. In a hurricane those waves can come in quick, short bursts as powerful thunderstorms around the storm’s eye wall swish air up and down like a plunger in a toilet bowl. Scientists have long known they exist, measuring them in the stratosphere about 20 or 30 miles above a storm.
Now, for the first time, University of Miami scientists have ventured into the heart of the storm, measuring the waves where they start.
And early indications suggest wave power relates directly to storm power.
“The waves are generated in the eye wall, where all the energy is released,” said David Nolan, who reported the findings with colleague Jun Zhang in the journal Geophysical Research Letters. “That’s why we think it’s telling us what’s going on with the storm. It’s like noise from the engine.”
If the connection reproduced on computer models proves reliable, it could provide hurricane forecasters with a new tool in monitoring what remains a stumbling block in hurricane predictions: understanding storm intensity. Improved satellites and supercomputers that collect and process more data faster have allowed forecasters to make huge leaps in narrowing the likely track a storm will take. But how they intensify, especially when cyclones do it very quickly, continues to lag.
Using measurements from the waves could also provide a simpler and relatively cheaper way to gather information to fine-tune predictions because data can be collected from buoys in the ocean or weather stations on land.
“Satellites are really expensive. Planes are really expensive. But barometers are pretty cheap,” Nolan said. “This could be a separate, independent way of keeping track of hurricanes and typhoons from a distance.” In addition to being cheaper and easier to retrieve, information provided by surface measurements could also provide a valuable backup system for forecasts that rely heavily on satellites, which can fail, or hurricane planes, which can take a long time to reach a storm.
Satellites are really expensive. Planes are really expensive. But barometers are pretty cheap.” David Nolan University of Miami scientist