JACKSONVILLE, Fla. – The sunrise never quite made its grand entrance over the First Coast Thursday morning. Instead, a thick blanket of clouds kept the sky in shades of gray.
But while we couldn’t see the sun from the ground, satellites peering down from space captured something remarkable—dark streaks stretching across the sky. These weren’t ordinary shadows. They were cast by contrail clouds—thin ice crystal trails left behind by high-altitude jets.
Between 7 and 8 a.m., the sun sat low on the horizon, its light slicing across the sky at just the right angle. As a result, these contrails—formed miles above us—projected shadows onto the lower, flatter stratus clouds.
From space, the effect was striking: delicate lines marking the paths of planes crisscrossing the upper atmosphere. North and south dark lines track the routes of planes crossing latitude while the westerly upper-level winds blew the contrails longitudinally toward the east.
Contrails form when hot jet exhaust meets the frigid air of the upper troposphere. Water vapor condenses, freezes, and turns into a trail of ice crystals, creating those thin, wispy clouds we see from the ground. Some disappear in seconds, while others linger, stretching and spreading based on the moisture in the air.
Another satellite view farther to the east where the sun was higher in the sky shows a different view of the contrails. Here you can’t see any shadows due to the acute sun angle but the white pencil thin consendation trails are visible.