In the Eye of the Storm

Hurricanes can be deadly, and those who have experienced the damage caused by these super-storms know just how important it is to have accurate information. Scientists who study hurricanes use a variety of methods to determine wind speed, direction, and severity of the storms, but most of those methods require costly equipment with limited accuracy. But with the help of GPS tracking, scientists may soon be able to acquire more accurate storm data with less expense.

Tracking Super-Storms

The most widely-used method of tracking hurricanes to date is to send storm-hunting aircraft (known as Hurricane Hunters) into the storm, dropping a series of scientific instruments sealed inside tubes at precisely determined points. The tubes, or dropsondes, gather data such as wind speed, pressure, humidity, and temperature as they fall. Because each dropsonde costs approximately $750, scientists usually use no more than 20 to 25 per storm. The packages are dropped in a pattern with the goal of gathering a complete set of data. However, the time and distance between the dropsondes means that there will be gaps in the data set which must be filled in by guesswork.

Now that GPS technology has entered the storm-tracking scene, that guesswork will be reduced to an absolute minimum. Typical GPS receivers pick up signals sent from satellites and use those signals to determine a precise geographical location. However, when the signals are transmitted over water, they reflect off the surface of waves, causing the signal to distort and scatter in multiple directions. In a hurricane situation, the receivers carried by the Hurricane Hunter aircraft can pick up the signals and record the distortions. Scientists can use that data to determine the size of the waves and roughness of the water, which in turn provide information about the strength and direction of the wind.

GPS Tracking on the Job

Hurricane Hunters already carry GPS receivers, and the satellite signals transmit continuously. That means the infrastructure and data transmission is already in place. Scientists must simply collect the data and use it to deduce information about the storms. Scientists hope to eventually use other strong satellite signals to supplement storm data as well. Satellites such as those used for DirecTV and Sirius XM Radio cost millions or billions of dollars, and the signals they broadcast are extremely powerful. By using the equipment already in place, scientists can create an effective storm tracking system that doesn’t require huge expense.

Two Methods, One Goal

One of the greatest benefits of using GPS tracking to monitor storm activity is that it can be analyzed almost continuously, filling in the gaps in the dropsonde data. However, the GPS tracking method is not without its drawbacks. Each method has strengths and weaknesses, making each an excellent complement to the other:

	Pros	Cons
Dropsonde Method	More precise wind speed measurements Can be used over land	Very expensive Widespread drop patterns create gaps in data
GPS Tracking Method	Cost effective Gathers data continuously Uses technology already in place	Cannot be used over land Less accurate wind speed measurements May not provide good data in areas where the water is choppy but there is little wind (like the eye of a storm)

Even though the two methods each have pros and cons, they complement each other and work together to accomplish the goal of providing the most accurate storm tracking data available. Although the data sometimes overlaps, experts say that dropsondes and GPS tracking usually measure different things. That means that both are needed to present a complete and highly accurate picture of what a storm looks like and where it’s heading.

Using the Data

While storm-chasing can be both fun and dangerous, the ultimate goal is to give people the information they need to make informed decisions. Knowing how strong a storm is, how fast it’s moving, and which direction it’s headed can save lives by giving people enough advance warning to evacuate when necessary. If there’s anything we as a nation have learned from national tragedies like Hurricane Katrina, it’s that preparation is key to surviving a hurricane. Although people may not always be able to save houses and possessions, accurate storm data can give communities enough advance warning to protect their families and loved ones.

As technology advances, GPS tracking provides the next step toward gaining better knowledge about weather patterns and how they will affect various parts of the country. It’s a step forward that could help scientists understand storms better and in so doing, save lives.

In the Eye of the Storm