Posts tagged ‘hoar frost’

Hoar Frost Morning—Glacial Ridge National Wildlife Refuge-March 9-10

There were 20 cases of books waiting for me in Pembina, North Dakota. My printer is in Altona, Manitoba and they kindly brought a pallet of books just across the U.S. border so I wouldn’t have to pay duty. And since I was going all the way there, why not do some photography on the way?!

I left Wrenshall at 3:20 am so I could be in far western Minnesota by sunrise. And I made it! Since the radio in the van doesn’t work, podcasts keep me entertained. As I turned off US2 into Glacial Ridge National Wildlife Refuge, I knew it was going to be a spectacular morning. Thick coats of hoarfrost coated everything! Every twig, branch, blade of grass, strand of barbed wire held a coating of thick feathery frost.

Glacial Ridge National Wildlife Refuge was established in 2004 and is Minnesota’s newest addition to the NWR system. It is a vast area, that will eventually encompass 37,000 acres (57 square miles)

It is described by the US Fish and Wildlife Service as “the largest tallgrass prairie and wetland restoration project in U.S. history.” [from wikipedia.com]

 

Conditions were PERFECT for hoarfrost formation….Temperatures at sunrise were near ZERO degrees F and dead calm, and the day before had been above freezing so I imagine moisture from the melting snow provided the “raw material” for spectacular hoarfrost formation.

Here is some info from http://www.wikipedia.org:

“Hoar frost (also hoarfrost, radiation frost, or pruina) refers to white ice crystals deposited on the ground or loosely attached to exposed objects, such as wires or leaves.[4] They form on cold, clear nights when conditions are such that heat radiates out to the open air faster than it can be replaced from nearby sources, such as wind or warm objects. Under suitable circumstances, objects cool to below the frost point[5] of the surrounding air, well below the freezing point of water. Such freezing may be promoted by effects such as flood frost or frost pocket.[6] These occur when ground-level radiation loses cool air until it flows downhill and accumulates in pockets of very cold air in valleys and hollows. Hoar frost may freeze in such low-lying cold air even when the air temperature a few feet above ground is well above freezing.

The word hoar comes from an Old English adjective that means “showing signs of old age”. In this context, it refers to the frost that makes trees and bushes look like white hair.

Hoar frost may have different names depending on where it forms:

  • Air hoar is a deposit of hoar frost on objects above the surface, such as tree branches, plant stems, and wires.”

[Sony A6500 with Sigma 50-500mm f4.5-6.2 OS HSM lens]

Sharp-tailed Grouse in frosty meadow. I ended up seeing 48 Sharp-tails in Glacial Ridge on Saturday.

[Sony A6500 with Sigma 50-500mm f4.5-6.2 OS HSM lens]

 

Hoarfrost on barbed wire fence.

[Sony A6500 with Sigma 50-500mm f4.5-6.2 OS HSM lens]

 

Cottonwoods on the edge of the prairie.

[Sony A6500 with Rokinon 10mm manual lens]

 

Coyote in frosty meadow. I tried squeaking and pishing to bring her closer, and it worked…kind of. She came back towards me, but only within about 200 yards.

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Northern Owls in a Hoar Frost Wonderland

When I left my house this morning (Dec 11th) I was a bit bummed as the skies were gray and the light flat. But when we started gaining elevation out of Duluth, a hoar frost wonderland began to appear. Every single bud, branch, needle and twig on every single tree was coated in a feathery frost. Spectacular! Now if we could only find some subjects! I was traveling with Dave Shaffer from Spooner, Wisconsin (one of the best Black Bear photographers in the country…see his images (all taken in the wild) at http://www.bearwitnessimages.com) and we were after one thing…Owls!

Most birders and photographers who love boreal birds have heard of northern Minnesota’s Sax-Zim Bog. It is a Mecca for those searching out lifers or photos of northern birds such as Boreal Chickadee, Black-backed Woodpecker, Sharp-tailed Grouse, Ruffed Grouse, Pine Grosbeak, White-winged Crossbill, Evening Grosbeak, Common Redpoll, Hoary Redpoll and, of course, owls. Great Gray Owl and Northern Hawk Owl are regular nesters and can be found easily most winters. Boreal Owls, Snowy Owls and Northern Saw-whet Owl are much more rare.

Great Gray Owl hoar-frost Admiral Road Sax-Zim Bog MN IMG_1794[Canon 7D with Canon 400mm f5.6 lens; f5.6 at 1/400, ISO 400, aperture priority]
Great Gray Owl atop a tiny Tamarack cloaked in hoar-frost, Sax-Zim Bog MN
After a couple hours of unfruitful searching, we spotted a dark blob far down the road. I knew instantly that it was a Great Gray…the Phantom of the North! This was Dave’s first ever Great Gray…a “lifer” in birder parlance. And what a bird! This guy (girl?) kept on hunting for over an hour as we watched and kept clicking the shutter.

This is probably my favorite image from the day. I lover the graceful curve of the Tamarack tip and the “bird in landscape” feel. It really gives you a sense of the boreal haunts of this magnificent bird. I tweaked the white balance to give it a more cool (blue) feel. Though these are the tallest owl in North America (30 inches tall!) they are all feathers and rank third in weight (behind Snowy and Great Horned).

Hoar frost Tamaracks Sax-Zim Bog MN IMG_1986Hoar Frost is relatively rare in the North Woods, but when it happens you better grab your camera and go! Here is a definition from http://www.weatheronline.com.uk
“Under clear frosty nights in winter soft ice crystals might form on vegetation or any object that has been chilled below freezing point by radiation cooling. This deposit of ice crystals is known as hoar-frost and may sometimes be so thick that it might look like snow. The interlocking ice crystals become attached to branches of trees, leafs, hedgerows and grass blades and are one of the most prominent features of a typical ‘winter wonderland’ day. However, the fine ‘feathers’, ‘needles’ and ‘spines’ might also be found on any other object that is exposed to supersaturated air below freezing temperature.

The relative humidity in supersaturated air is greater then 100% and the formation of hoar frost is similar to the formation of dew with the difference that the temperature of the object on which the hoar frost forms is well below 0°C, whereas this is not the case with dew. Hoar frost crystals often form intitially on the tips of plants or other objects.”

Great Gray Owl hoar frost Admiral Road Sax-Zim Bog MN IMG_1954
Great Grays are powered by voles—both Meadow Vole and Red-backed Vole. Some studies have shown that their diet is 97% voles. Their talons are tiny compared to Great Horneds which eat much larger prey (rabbits, squirrels). And voles must be in good supply as this guy caught two back to back within minutes.

Great Gray Owl hoar frost Admiral Road Sax-Zim Bog MN IMG_1592

Great Gray Owl hoar frost Admiral Road Sax-Zim Bog MN IMG_1592 - Version 2The two images above are just different crops of the same original image. Which do you like better? [Canon 7D with Canon 400mm f5.6 lens; f5.6 at 1/320, ISO 400, aperture priority, tripod]

Great Gray Owl hoar frost Admiral Road Sax-Zim Bog MN IMG_1739[Canon 7D with Canon 400mm f5.6 lens; f5.6 at 1/320, ISO 640, aperture priority]

Great Gray Owl hoar frost Admiral Road Sax-Zim Bog MN IMG_1882 (1)[Canon 7D with Canon 400mm f5.6 lens; f5.6 at 1/125, ISO 500, aperture priority, tripod]
At dusk we found another Great Gray along McDavitt Road, about a mile or two from the other bird (as the raven flies). Thankfully Great Grays often pick photogenic perches in this stretch of road that has NO power poles or fence posts!

Great Gray Owl hoar frost Admiral Road Sax-Zim Bog MN IMG_1850[Canon 7D with Canon 400mm f5.6 lens; f5.6 at 1/125, ISO 640, aperture priority, tripod]
The spruce boughs in the background hint at this bird’s wild far northern haunts.