Flying a plane into a hurricane might not be on everyone’s to-do list this summer, but a UH research associate professor has it at the top of his.
James Lawrence, a research associate professor of geosciences at UH, leads a team in which a specially designed device is flown on a research aircraft into hurricanes. The device measures the amount of salt contained in the correlating rain.
Known internationally as a tropical cyclone, or TC, a hurricane accumulates salt content by sucking up seawater as it rotates around its central vortex, otherwise known as the eye.
Measuring the amount of salt in the rain at different locations inside the TC can help map the distribution of sea spray at the surface of the ocean, Lawrence said.
‘This is important because sea spray is most intense in Category 3, 4 and 5 hurricanes,’ he said.
His hypothesis is that ‘sudden changes in sea spray accompany or may precede increases in hurricane intensity.’
Lawrence noted that 95 percent of all hurricanes are rated as Category 1 or 2. Category 3, 4 and 5 hurricanes are of most interest to meteorologists.
Considering the difficult task meteorologists have in predicting the changes in tropical cyclone intensity, Lawrence said he expects his device to help them in prediction capability, or to gain an understanding of sea spray and TC intensity change.
This device for taking such measurements was created by UH Chemistry Department Director of Instrumentation Hans Hofmeister, and is named the ‘salinity device,’ because salinity refers to the level of salt content in a liquid substance.
The project started in 2003, when Lawrence approached Hofmeister to construct a device capable of electronically measuring the salinity of water.
The original device was constructed with platinum wires, each one alternately separated from the other by positive and negative electronic charges. As rainwater passes through the charged wires, its salt content increases the electrical current.
The team tested the salinity device by mounting the instrument on Lawrence’s pickup truck as it was driving on Interstate 45 in Houston.
After the testing, the National Oceanic and Atmospheric Administration (NOAA), the organization responsible for coordinating TC research, determined that Lawrence’s project was less of a priority than its other various hurricane research efforts.
‘We were always at the bottom of the totem pole,’ Lawrence said.
In 2007, things changed for Lawrence when a NOAA research plane reported severe salt encrustation in its engines – the second of such major malfunctions for the aircraft in the NOAA’s Hurricane Research Division.
This first occurred in 2003, when a research aircraft’s crew lost one of its four salt-encrusted engines as it flew through a hurricane. The crew traveled home safely, but under the power of only three engines.
With engineers realizing the importance of monitoring the levels of salt accumulation on the aircraft, the salinity device immediately soared to the top of the list of instrumentations to be included on NOAA hurricane flights.
The device flew on its first NOAA mission in November 2008 through Hurricane Paloma, considered the fifth major hurricane in 2008. Paloma was affecting areas in the Atlantic Ocean, including Honduras, Florida, Cuba and the Bahamas.
During the Hurricane Paloma mission, the salinity device was flown at 15,000 feet above sea level and was slightly damaged due to high-altitude ice.
Lawrence’s team has since restructured the salinity device to make it sturdier. On the newly constructed prototype, titanium plates, embedded in epoxy, replace the platinum wires. The epoxy is expected to protect the titanium plates from contact with debris.
The newer version of the device will be tested at Texas A&M University’s wind tunnel in mid-July. With one mission under his belt, Lawrence and his team plan to fly the device on all of the NOAA hurricane research missions this season.
Though the flight crew can operate the device without him onboard, Lawrence said he prefers to be there in person.
‘If they have a seat open, we’ll be on it,’ he said.
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