This Mysterious Weather Phenomenon Can Kill Skydivers On A Clear, Calm Day
The reason for the parachute's sudden failure may have been a strange weather phenomenon known as a dust devil, according to the owner of the skydiving facility.
United States Parachute Association National Director Rich Winstock agreed that a so-called dust devil, comprised of wind and dust churned into a funnel, killed Rikers Island correction officer Gary Messina.
"The instructor was rendered helpless to counter the mini-tornado," Winstock said in a statement to Newsday. "In fact, he did his very best to avoid or outrun the weather abnormality, trying to reach a safe and open landing area."
A dust devil is defined as a "well-developed dust whirl; a small but vigorous whirlwind, usually of short duration, rendered visible by dust, sand, and debris picked up from the ground," according to the American Meteorological Society. They have diameters ranging from 3 meters to upwards of 30 meters and can cause minor damage equivalent to F1 on the Fujita scale that is used to rate tornadoes.
Dust devils are similar to mini tornadoes, with wind speeds up to 75 miles per hour capable of extending from the surface up to several thousand feet, according to the United States Parachute Association (USPA).
They typically form where there is uneven heating of the Earth's surface, such as at a location where pavement meets dirt. As the sun heats the surface the hot air, less dense and lighter than the cooler air above it, rises and and begins to rotate, according to an explanation by USPA Director of Safety and Training Jim Crouch. As the rotation increases, the air compresses and creates a tight, spinning funnel.
They can be particularly hazardous to skydivers because they form in clear skies when there is little to no wind - perfect skydiving conditions - and because uneven ground heating can occur at drop zones where grass meets asphalt.
Dust devils can also form nearly anywhere and can be practically invisible when they occur over surfaces where there is no debris to kick up into the funnel, making it hard for descending skydivers to spot them.
Before last week's incident, dust devils had already killed and injured several skydivers in the past decade. A similar incident occurred in 2012, when 51-year-old Richard Frazer was caught in a dust devil as he drifted toward the ground after a skydiving jump in Nevada, reported the Las Vegas Review-Journal. The whirlwind caused Frazer's parachute to either lose lift or fold, and he fell to his death.