Airplanes and Frigid Air TemperaturesPosted on January 30, 2019
With the current cold snap sweeping the Twin Cities, airport neighbors may be hearing airplanes in a different way.
Like many things in aviation, there is a scientific explanation for why the aircraft sounds you hear on a bitterly cold day may vary from the same aircraft on a warm day.
“Temperatures and humidity affect the way sound waves travel through the air,” said Derek Anderson, the acoustics and data analysis coordinator at the Metropolitan Airports Commission. “On a day like today, with cold temperatures and low humidity, sound waves travel farther before dissipating. The absence of leaves and grass on the ground and high winds also lead to sound traveling farther distances.”
Cold temperatures also bring some benefits to airport neighbors impacted by aircraft noise. Cold air has higher density which leads to higher performance by jet aircraft. Higher air density improves acceleration, reduces runway lengths needed during take-off, and increases lift and altitude gained as aircraft fly away from the airport.
“Sub-zero temperatures have been known to increase altitudes by 500 feet just two-and-a-half miles away from the airport compared to summer months,” Anderson said.
For folks who prefer warmer temperatures, these below-average temperatures are temporary. By Thursday, the winds are forecast to be out of the south, bringing above-normal temperatures for this time of year.