Arctic Oscillation

An amazing site of ice crystals and sunlight in the eastern sky on Christmas eve morning.

January 6, 2023 – The last weeks of 2022 brought a bone-chilling assault of arctic cold with snow and relentless strong winds to the midwest. The high winds pushed temperatures down into negative double digits, impacting most of the United States east of the Rockies for about a week. Here in the Midwest, the dangers from the extreme cold were real, and the constant winds made it easy to imagine what it is like to be in a winter storm high in the Arctic. The cold temperatures froze moisture on contact, and the clear morning sky on Christmas eve displayed a beautiful parhelic circle and halo with iridescent red and blue sundogs flanking the sun above the eastern horizon. The sun was at the center of the icy atmospheric phenomenon and appeared like a giant glowing diamond floating in a fog of ice crystals. Flocks of foraging winter birds at the road’s edge fighting the fierce winds were swept hundreds of yards within seconds when flushed. Lapland longspurs wintering far from their Arctic nesting range were battling powerful gusts as they searched for seeds trapped among the rocks along gravel roads. Large flocks of Horned larks dotted the windswept fields and road edges as they foraged for much-needed nourishment during the extreme weather. Like other birds here during the winter in Northern Illinois, the Lapland longspur and Horned lark generate heat by feeding continuously on spilled seeds left by man and nature during daylight hours to help them stay warm during extreme weather events. At night the small birds fluff their feathers, find hollows and wind blocks and even shiver to generate heat. During harsh winter conditions of strong winds and cold, I have witnessed longspurs taking breaks from the strong winds by using small depressions in the snow, like little snow caves, during the day to protect themselves before going back to feeding. The somewhat rare weather event known as a “bomb cyclone” struck Christmas week and was a challenge for wildlife. The heavy snows first predicted here in Northern Illinois did not transpire. An accumulation of several inches or more did arrive with the powerful winds creating a hazardous situation for all living things. The strong winds produced some bitter cold but helped by sweeping the fields and roadways of snow, making it easier for the birds to forage and get to those energy-producing seeds that keep them alive through the nights during the unusually rapid Arctic cold blast.

Horned larks foraging along a gravel road in Iroquois County during strong winds and bitter cold.

Winter Larks

A Horned lark flushed from the roadside where it was searching for food landed on the undisturbed snow nearby.

February 11, 2021 – The bitter winds from an Arctic blast of snow and falling temperatures arrives in Northeastern Illinois. Temperatures drop as a result of a strong negative Arctic oscillation which indicates that some very cold air has meandered out of the Arctic and moved south across Canada and into the northern United States. The Arctic oscillation is an index of mean weather data that meteorologists and climatologists use to understand the stability of the weather over the pole. The weather data moves the Arctic oscillation index between negative and positive numbers, mild winter weather would be indicated by the latter. As the challenging cold weather takes hold, ice quickly forms on our river, and open water on ponds and creeks begins to disappear as the icy blanket is pulled tight. The muffled sounds in the winter air cause us to trust our other senses a bit more. The honking voices from a flock of Canada geese flying overhead is softened by the snowy landscape of sound absorbing crystals in the new snow. During these harsh cold conditions geese and dabbling ducks begin to look somewhat ragged and spend more time hunkered together with little movement. Diving ducks like Common goldeneye continue their hunt for crayfish in the rivers’ open waters. Along the snowplowed country roads and on the high areas of windswept agricultural fields Horned larks fight strong winds searching for small seeds in the exposed areas. At times the little birds try to walk across the icy road only to be blown by a strong cold gust causing them to skate most of the way across while using their wings to balance. Horned larks are in Illinois year- round and are considered resident to short-distance migrants. During the winter months the number of Horned larks increase as birds from further north come south to winter in Illinois. This is a good time, especially when we have snow, to locate and observe the little larks along with Lapland longspurs and Snow buntings foraging the edges of less traveled rural roads where it can be done safely. Snowplows expose grassy areas where small seeds can be found by the larks when other areas are buried under deep snow during those brutal and challenging periods of winter.

Hunting the edge of a rural road, a pair of Horned larks battle a steady wind as they search for seeds.