New global satellites look deep in the eye of the storm

With the ten year anniversary of Hurricane Katrina just around the corner, innovations in storm surge predictions have come a long way. To learn more about recent developments in hurricane technology, "TechKnow" spoke with Dr. Christopher Ruf, a professor of atmospheric science and electrical engineering at the University of Michigan. Dr. Ruf is the principal investigator on the Cyclone Global Navigation Satellite System (CYGNSS), a NASA satellite project set to launch in 2016 with the goal of dramatically increasing the accuracy of hurricane forecasting.

Dr. Ruf discusses with "TechKnow" why Hurricane Katrina caused so much damage, and how CYGNSS will help prevent future hurricanes from causing so much devastation. 

The following was adapted from an interview with “TechKnow.” It has been edited for length and clarity.

TechKnow: Can you explain what CYGNSS is, and why it’s an improvement on our current methods of forecasting hurricanes?

Dr. Christopher Ruf: CYGNSS is a constellation of 8 small satellites that are going to be orbiting over the tropics. The instruments on each one of the satellites are able to measure the speed of the wind in the middle of a hurricane. It’s the first time ever that we’re going to be able to make these kinds of measurements, so that’s pretty exciting.

TK: How does this factor into being able to improve early storm detection?

CR: So it’s not really early storm detection, but detection of how the storms are going to change into the future. The way that hurricanes are measured now, you can’t measure what’s happening in the middle of a hurricane from a satellite. The only way you can measure the center of a hurricane is by flying an airplane into it…When hurricanes start getting close to the shoreline, the National Weather Service starts to fly these special Hurricane Hunter airplanes out and make measurements inside the hurricane of how strong the winds are. The CYGNSS satellites will be able to take similar measurements, only from a satellite.

TK: Do you believe CYGNSS will make a tremendous impact on what we know about hurricanes?

CR: I think so. You can see it by comparing some of the past experience of forecasting using these airplanes, the Hurricane Hunter airplanes, which make measurements very similar to what we’ll be making. A good example is Hurricane Sandy…as it was moving up the east coast, there were many airplane flights over it. And in large part because of that our ability to forecast the strength of the hurricane, the extent, the storm surge, where it made landfall, what the height of the water would be when it made landfall, all of those things were very accurately forecast. And that quality of forecast I think is indicative of what we’ll be able to do routinely with CYGNSS because it will be making measurements roughly similar in quality and quantity to what was done with Sandy.

TK: Why was Hurricane Sandy tracked and measured so well?

CR: The reason Sandy was sampled so well is two-fold. Because it was heading towards New York, a huge metropolitan area, there was a lot of attention paid and a lot of expense getting the airplanes out there to make the measurements. And since it was fairly close to land, it was relatively easy to get the airplanes out there. They could fly from an airport and come back and land again. So those two things together allowed it to be sampled much better than the average hurricane. Whereas with CYGNSS, the satellites will be everywhere in the tropics all the time, so no matter where the hurricane is, we will able to measure them more or less as often as Sandy was measured.

TK: What aren’t we good at right now when it comes to predicting a hurricane?

CR: Probably two primary things. One is the intensity of the hurricane, or the CAT number, which is a measure of the maximum winds in the hurricane. The other thing is the storm surge, and the storm surge is, by far, what causes the most property damage and loss of life. But our ability to predict the storm surge is very poor right now, and it’s because we don’t make enough samples of the structure of the wind. CYGNSS is expected to have the largest impact on our ability to forecast the storm surge. And the problems with storm surge are very well illustrated by what went wrong with Katrina. The storm surge forecast was way off.

TK: Let’s say we had your satellites up when Katrina hit. How would they help the people of New Orleans?

CR: By and large the biggest impact is on loss of life. If you know where the floods are going to flood, and when and how much, you have a much better ability to warn people to evacuate and just get away from the coastline. The amount of flooding, especially in Mississippi and down in to New Orleans was much bigger than expected because of the blown storm surge forecast…Being able to forecast better does two important things. One, it just gives you better information right now, for any given storm. But second, I think there’s an important psychological aspect with improved reliability and forecast.  When forecasts are wrong, people tend not to trust the next forecast as much. If they know that forecasts are reliable and they tend to be correct, they’re much more likely to listen when there’s a forecast for an emergency. That’s a huge potential benefit to having something like CYGNSS up and running.

To learn more about Dr. Ruf’s hurricane tracking satellites, look out for TechKnow’s Hurricane Katrina special, set to premiere August 24th.