Monday, June 10, 2013

Using Unmanned Aircraft for Severe Thunderstorm Prediction and Warning

After the tornado outbreaks in Moore City and Oklahoma City, Oklahoma, there was a flood of controversy about the role of storm chasers.   With the tragic loss of three experienced storm chaser/scientists, the injury of the several Weather Channel chasers (see picture below of their car), and the veritable traffic jam of chasers in the immediate vicinity of the Oklahoma City tornado (see image), a number of observers have suggested that there must be a better way of observing tornadoes.

Furthermore, when a severe thunderstorm pops up in an unexpected location (and this happens plenty of times), there are often no chasers in the neighborhood to give the National Weather Service ground-truth observations.
Position of storm chasers (with GPS and who reported their position) during the Oklahoma City tornado event.   There were certainly more chasers than this in the area.  The background image is the Doppler velocities, with the yellow/blue couplet indicated the mesocyclone of the storm

We need a way that puts fewer chasers at risk, reduces the potential for chaser-induced traffic jams, and collects more useful information.  An approach that would allow the National Weather Service to get the information they need when storms develop unexpectedly.    And a way to get large amounts of information before severe thunderstorms develop and thus enhance short term (1-12 hr) forecasts.

Could such a breakthrough be possible? 

I believe that answer is emphatically yes.

The approach?  Take advantage of small unmanned aircraft capable of providing both video and weather information while in flight.  And as I will explain below, the planes are ready for action and available from a local company here in the Pacific Northwest.

Imagine you had a small, relatively inexpensive aircraft (costing roughly 50 K$) that had the ability to fly with a high-definition video camera and the same weather instruments in radiosondes (balloon launched weather sensors).  The plane would have a large range (1000s of km) and the ability to stay aloft for extended periods (1-2 days).   A plane that had GPS so an accurate position was known at all times, satellite communication (so it was in constant communication), a sophisticated onboard computer for data collection and flight control, great strength (so severe turbulence would not damage it) and the ability to be easily deployed and recovered.

Such a plane, under the control of National Weather Service staff (or a private firm hired by the NWS) could fly out to potential tornadic storms and fly around funnel clouds or threatening structures (e.g., rotating wall clouds).   Continuous imagery of the developing tornado, with accurate position information, would be available to NWS forecasters, along with insitu observations from the aircraft sensors.   All of this could be done with complete safety and high reliability.     If a new storm developed, such small aircraft could be deployed quickly and, with speeds of 50-100 mph, could get into position quickly and safely (unlike some overly exuberant chasers that drive very fast over rain-slickened roads).    Perhaps you could get an idea of the view of such a small aircraft from the imagery sent back by some TV helicopters during some events (see below).  The imagery could be fed to local TV stations and emergency managers in real time.



 I should stress that it would not be necessary to fly such aircraft into the storm, but just to keep a respectful distance (not unlike the TV helicopters do near some major cities).  The large hail and heavy rime icing in severe convection would not be good for the health of these small aircraft.

Amazingly, an aircraft capable of such unmanned surveillance is now available for purchase from the Aerovel Company of White Salmon, Washington.  Aerovel is a company founded by Dr. Tad McGeer, an extraordinarily talented and innovative aircraft designer, who has created a series of highly successful small Unmanned Aerial Vehicles (UAVs), including many that are now used by our military (e.g., the ScanEagle).   His firm has now developed and successfully tested the Flexrotor, a small aircraft capable of taking off vertically like a helicopter, going into horizontal flight, fly a long mission, and then return to base, landing as a helicopter (see picture).   Go to this web site to see an amazing video of a flight.  A technological triumph.


The current version of this aircraft has amazing capabilities, including a 3,000 km range and an ability to stay aloft for 40 hr, while carrying the instrumentation and video cameras noted above.  It could revolutionize the monitoring of severe storms, and provision of warnings to local residents and businesses.

But the great potential of this aircraft does not end there.   Before storms develop it could fly in the lower portion of the atmosphere (lower few thousand feet) in a way to get voluminous observations of the environment in which convection (thunderstorms) will develop.   Many of us believe that this is an essential ingredient for further progress in severe storm prediction.  In fact, an experiment using manned aircraft (the Mesoscale Predictability Experiment, MPEX) is going on this spring to prove this hypothesis. 

And after severe storms hit, such small aircraft could get extensive imagery of the damaged area to aid first responders and others.

So what stands in the is way of this vision?

First, the National Weather Service needs to consider the potential of such aircraft seriously and funds for the experimental use of the small planes must be found.  Perhaps a local foundation (e.g., Gates, Bezos, Allen) could fund a demonstration project.

Second, the Federal Aviation Administration (FAA) must allow these planes to fly in U.S. airspace.  To put it mildly, the FAA has not  encouraged unmanned aircraft and has severe limitations on this use.  They need to rethink their objections for  UAVs applied for storm forecasting.  Such planes could potentially save many lives.  They will do most of their flying around severe thunderstorms, where few commercial or general aviation flights dare travel.  The planes will be in constant contact with controllers and their positions will be known at all times, so other aviation will be constantly appraised of their position. 


It would be ironic if we could use unmanned aircraft to kill and damage our foreign enemies, but were unable to use them to save many American lives.

Small unmanned aircraft have the potential to revolutionize severe storm prediction and warning, and would give the National Weather Service a powerful tool for protecting American lives and property.  Such UAVs have other potential  meteorological applications, like hurricane reconnaissance.   I believe they are the future, but it will take some effort and vision to make it a reality.


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