As is well documented, hurricanes are getting stronger. The likelihood that a hurricane will be Category 3 or higher is increasing by about 8% per decade. These storms carry sustained winds of at least 110mph, which can cause billions of dollars of damage.
To brace ourselves for stronger storms, engineers are developing increasingly durable devices for monitoring extreme ocean conditions. In-situ measurements are critical for measuring hurricane formation and evolution: the best sensing systems withstand violent surges, sustain extended periods without power and maintenance, and upload data in real-time. Meteorologists deploy networks of these systems along coasts and in the eyes of storms to enhance individual observation accuracy and predictive capability of hurricane forecasts.
Existing challenges in storm tracking
Hurricanes have always been difficult to predict. Meteorologists have become relatively adept, in recent years, at predicting where a storm is headed. However, predicting the intensity of a storm is more challenging.
“Broadly, generally, we know whether a hurricane is going to intensify or weaken. What we can't really tell is whether it's going to rapidly intensify,” Angela Fritz, a meteorologist with The Washington Post told NPR. “ And that's something that we keep hearing over and over again, especially over the past decade or so, about these rapidly intensifying hurricanes.”
The rise in sea surface temperature is one contributing factor that makes it difficult to predict how intense a storm will become. Warmer seas contribute to more intense storms, but as Fritz explained, “We just don't quite have the knowledge available to us and the equations available to us to predict exactly when and how it's going to intensify.”
In the past, scientists would use satellites or large, moored buoy platforms to observe extreme weather events at sea. These methods often provide invaluable — yet limited — data. Satellites, for instance, cannot report on extreme conditions due to poor reliability in heavy rain.
Another obstacle toward collecting data lies in the approach. Climate simulations show the likelihood of a storm’s intensity, but confirming the results of a simulation has been problematic due to the relatively few hurricanes that take place each year. In the US, storms that pose no threat to populations are measured less than others.
“We’re collectively doing a bad job of measuring tropical cyclones around the world,” Dr. Kerry Emanuel, a hurricane expert at MIT told the New York Times. “We’ve all believed we should see more intense hurricanes. But it’s very very tricky to find it in the data.”
Technology is evolving — and so are storms
Hurricane Dorian was one of the earliest indications that hurricanes are becoming more unpredictable and more intense. Hurricane Dorian defied expectations of both its strength and movement, changing course hour by hour and picking up energy faster than forecasted as it crossed the Caribbean.
In response, organizations all over the world are investing in technology that can improve data collection. NOAA alone collects 20TB of data every day using satellites, ground monitoring stations, specialized sea buoys, weather balloons, and even bees tagged with GPS devices.
Hurricane “hunters” also provide important data directly from the storm itself. Flight teams release an instrument pack called a dropsonde from above the storm. The dropsonde collects data as it falls to the ground, including temperature, wind speed and direction, humidity, atmospheric pressure, and GPS coordinates. Data is relayed back to the National Hurricane Center and other research organizations.
This method provides great data while a storm is happening — but it doesn’t go far enough to help experts get ahead of the storm. Predicting extreme weather is contingent on high-quality data — data that can improve the models we use to build flood maps, provide early weather warnings, and predict local sea level rise.
How weather buoys can help
Hurricane preparedness and coastal resilience worldwide depends on how much ocean data we gather and what we do with it. Distributed networks of low-cost oceanographic buoys maximize data input and optimize derived hurricane models.
Sofar Ocean owns the largest private network of open ocean buoys in the world, each reporting wave height and spectrum, peak period, wind, current, and surface temperature measurements in real time.
Last summer, six cyclones passed over Sofar's dense buoy network in the South Pacific. Several Spotter buoys floated into the eye of Tropical Cyclone Niran, which ultimately grew to be a Category 5 severe tropical cyclone with winds reaching 160 miles per hour. The observations recorded by these Spotters were assimilated into Sofar’s predictive marine weather models to examine the temporal evolution and spatial organization of the cyclone.
Last year, the USGS St. Petersburg Coastal and Marine Science Center used a Smart Mooring to enhance the USGS/NOAA Total Water Level and Coastal Change Forecast with real time wave, tide, and storm surge data. Sofar’s Smart Mooring allows for easy integration of any sensor and immediate data access. Anchored to a Smart Mooring, a Spotter can record and report measurements from anywhere in the ocean, rain or shine. Developed to streamline insight, Smart Mooring fast-tracks discoveries at sea.
Sofar’s systems are being used to calibrate and validate coastal storm forecasts by experts around the world. Scalable sensor networks prove to be a promising strategy for improving future hurricane observations.
To learn more about hurricane tracking, visit the Sofar Ocean blog.