In aviation, winds are almost always a losing proposition. Enroute or landing, windy days result in longer flight times and fewer runway choices. So it is somewhat surprising that Global Warming may have some beneficial effects, at least for aviation. In a peer reviewed study to be published in the Journal of Geophysical Research, the studies lead author, Sara Pryor, an atmospheric scientist at Indiana University, says that the data shows that there has been a jump in the number of low or no wind days in the Midwest. The study suggests that average and peak wind speeds have been slowing since 1973.
Unfortunately, this dying wind phenomena which may or may not be associated with Global Warming or Climate Change (depending upon whether you would like to hedge your effects bets or not), is especially ironic for the wind power industry. "It's a very large effect," said study co-author Eugene Takle, a professor of atmospheric science at Iowa State University. In some places in the Midwest, the trend shows a 10 percent drop or more over a decade. That adds up when the average wind speed in the region is about 10 to 12 miles per hour.” "The stations bordering the Great Lakes do seem to have experienced the greatest changes," Pryor said Tuesday. That's probably because there's less ice on the lakes and wind moves faster across ice than it does over water, she said.
In the event of global warming, it can be expected that the Arctic and Antarctic and their associated air masses will warm faster than the rest of the globe. Current temperature records, especially in the Arctic, seem to show this. That means the temperature difference between the poles and the equator decreases and results in a decrease in barometric pressure difference. Those pressure differences are a significant element driving strong winds. If the pressure differential decreases we would expect to see lower wind velocities.
Yes, the current data does not provide the irrefutable proof that science requires to connect reduced wind speeds and global warming. However more data may allow stronger correlations to be determined. Other scientists in the field have not found definitive trends of reduced surface wind speed. Location of data collection instruments, tree and foliage growth, as well as buildings can greatly effect the data and its interpretation.
So what does all this mean to Aviation Fuel Economy? The flight performance engineers at Air2Air ran simulations to determine the effect of reduced average winds on our fuel economy. The results can be summarized as follows, lower average winds mean lower average fuel consumption.
A simple wind effect flying example is a round trip from Carlsbad McClellan-Palomar Airport to Las Vegas Henderson Airport with a 120 mile per hour tailwind going to Las Vegas. In a normal no-wind simulation, the total flight time each way would be one hour and 20 minutes. Two hours and 40 minutes round trip. In the case of the 120 mph tailwind going and a 120 mph headwind returning, the first half of the trip to Las Vegas takes only 50 minutes! However, the trip back takes over three hours and 20 minutes. The total trip, in the simplified for effect ridiculously windy conditions, takes a total of four hours and 10 minutes! Thats a total trip time increase of over an hour and 30 minutes!
Even when the flight winds are 90 degrees to the flight track, winds have a significant effect. Once again, simplifying with big numbers and flying to and from Las Vegas with a 120 mph cross wind, the normal one hour and 20 minute leg each way becomes one hour and 40 minutes each way. Thus making the trip a total of three hours and 20 minutes. An increase of over 40 minutes.
So, in general, unless you can figure out a way to shut down the winds when you need them shut down and put them on your backside when you want them, winds are bad, at least in aviation.
