Autumn Leaves in Winter’s Rime Time

February 06, 2017

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Photographer: Ray Boren
Summary Author: Ray Boren

Rime crystals fringe pale autumn leaves clinging to branches of a field or hedge maple (Acer campestre) in this photograph taken on a nippy New Year’s Eve day 2016 in Utah’s large Salt Lake City Cemetery. With a foot (30 cm) of snow on the ground from recent storms, the midmorning temperature was 21 F (-6 C), and fog enveloped much of the city. In fact, crystalline specks were floating all around, like the tiniest of snowflakes in the frigid air.

Rime, also called hoarfrost, develops when supercooled water droplets, suspended in the air, as in these foggy conditions, freeze onto available surfaces, including trees and plants. At times accumulating hoarfrost can become so layered and heavy that large trees will bend from the added weight.

Nearby deciduous trees in the cemetery had lost all of their leaves by this date. According to Jason Baker, curator of plant records at the University of Utah’s Red Butte Garden, the hedge maple’s still-bountiful crop could be hanging on for various reasons, even though the tree is fully dormant for the winter. Other trees may have offered just enough shelter to protect it. Or, since the species is not native to North America, but to Europe, southwest Asia and north Africa, the tree’s genetic timetable may not yet be keyed precisely to Utah’s seasons.

Photo Details: Camera Model: NIKON D3200; Lens: AF-S VR Zoom-Nikkor 70-300mm f/4.5-5.6G IF-ED; Focal Length: 140mm (35mm equivalent: 210mm); Aperture: ƒ/5.6; Exposure Time: 0.0020 s (1/500); ISO equiv: 360.