Two recent letters to the editor in the Grand Forks Gazette have expressed concern regarding the trails left by passing aircraft.
Those trails are con trails or condensation trails.
An aircraft burns fuel to power the engine and discharges exhaust in the form of water vapor with traces of carbon.
The patterns formed by these trails are a result of high altitude wind direction changes.
It takes a while for the condensation to dissipate so the wind pushes the condensation into various patterns.
Aircraft fly at high altitudes in thinner air to save fuel. The temperature at 10,668 metres is about 30 below, at which point water vapor from the aircraft exhaust crystallizes and forms a trail. If the air is especially dry and clear it is more noticeable.
There is no sinister plot to poison those below, just the laws of physics in action.
The most dangerous daily routine is driving a vehicle where the exhaust is produced from the same action as in the aircraft – burning fuel and producing vapor.
If you have witnessed cars driving on a winter morning where the temperature is 20 or 30 below, the same visible “con trail” can be seen behind them.
Fortunately, the oil companies have removed the lead from the gasoline when they recognized the hazard in this exhaust to those driving behind.
If you want to protect your family, reduce your driving and idling and encourage everyone to do the same.
Ann M. Gordon,