And Down Came The Snow NEW!
With much of southern Michigan under a winter storm warning Feb. 2 and 3, those who ventured out across campus did so amid a gentle, but steady, snowfall. These photos capture some of powdery landscape at U-M. Click an image to view a larger version.
And Down Came the Snow
There is a lot of snow out there this winter. How much? It depends on where you are. While Duluth is breaking - or on the cusp of - all kinds of snowfall records for December and the season, areas in Carlton County are not quite setting records. But the snowfall we've had is far above normal.
In Cloquet, the average snowfall in December is about 16 inches. Last month, there was nearly 30 inches of snow recorded in the city. That is the highest of area measurements. A recording 3 miles northeast of Cloquet came in at 27.6 inches. Northeast of Carlton, 25.6 inches fell in the month. Moose Lake had 28 inches.
"After a record-breaking December, our office in Duluth is currently at a total of 68.1 inches of snowfall this winter," one post on Twitter read. "Normal seasonal snowfall up to (Jan. 7) is 39.5 inches. How long would it take for us to get back to normal? If no additional snow fell, we wouldn't reach normal until March 2."
Snowfall since an inch fell in October came in at 47 inches in Cloquet by Jan. 11, just 20 inches shy of the average snowfall for the year. It's virtually guaranteed - after just the second week of January - that Cloquet will see seasonal snowfall far above normal. It was snowing Wednesday, with a few more inches to add to the total. Hitting the monthly averages alone would bring about 30 more inches of snow to Cloquet, making the seasonal total of 77 inches, far above the snowfalls of recent years and 11 inches above the all-time average.
The record for snowfall in one year in Cloquet is 114 inches, recorded in 1950-51. That December, Duluth set its mark for the month at 43.3 inches, the 72-year-old record that was surpassed two weeks ago.
In the eight winters since that snowy 2014, average snowfall in Cloquet has been 58 inches, below the average of 66. Beginning with the 2019-20 season, snowfalls the past three years have been 71, 54, and 66 inches.
Despite more snow and a possible new record for the city, it could always be worse, right? Consider that high snow mark set in 1951 at 114 inches. The year before, 1949-50, 108.5 inches fell. The year after the record was set, 1951-52, 95 inches fell. That's one snowy trifecta.
We came across some "silver lining" words from columnist Gretchen Lamberton in the May 18, 1951, issue of the Winona Republican-Herald, as she marveled at spring blossoms decorating the landscape in that southeastern Minnesota city:
"Along about the third snow in April I began to have the uneasy feeling: Supposing that this is the year that spring doesn't come. Supposing the Good Lord is just plum fed up with the wicked foolishments of the world and just decided to withhold spring.
It was finally winter! The SnowPeople tumbled and frolicked in the sparkling snowflakes, chortling with pleasure at the frosty air. Friends greeted friends, so happy to be outside after the long summer and fall hibernation. Families hugged each other and did their happy dances!
Where, oh where, could Father Snowman be? The SnowPeople began to mutter, wondering if he was lost to them forever. It got quieter and quieter in the snowflakes, as the village got worrier and worriered.
I was headed out back to put braces in our big hoophouse that had just had a blanket of snow knocked off it when I heard two loud cracks and down came a tree on the property to our west. We lost a good-sized limb out of the Japanese maple growing at the northeast corner of the house. It had a weak crotch with a rotted spot. In knocking snowfall off the other limbs I was bombarded with the wet stuff.
Here they came, four and twenty blackbirds (redwings); and beneath, the bottom feeders, a couple dozen juncos earning their nickname of snow birds. A second varied thrush showed up and set about scratching through the bark mulch beneath our pink-flowering currant next to the house. Then it crossed over the porch floor to the mulch on the other side.
Song sparrows, Stellar jays, and mourning doves swung in too. Strangely, the two kinds of chickadees were not to be seen. But the most comical act in this circus was a couple squirrels that came down out of our large pine tree to cross over to our shrub island, but literally had to swim in the snow to get there; so I had to make another trek with an emergency resupply.
Augustine was super excited to build her own Olaf, and we had already decided that open snow-play was the best way for our daughter to discover snow at her own speed. So, we headed up to the top of Silver Mountain to build snowmen, throw snowballs, and hike a bit. (Also, a day of playing in the snow would let us all figure out how to make our daughter comfortable in her bibs, jacket, gloves, hat, and unicorn boots.)
Of all the mountain sports offered, snowshoeing is definitely the least traveled by resort guests. With piles of unpacked snow, we were able to pat down areas of the trail and let Augustine dig into the powder like it was our own private forest.
For snow to fall, moisture must be present in the atmosphere. Snowstorms also rely heavily on temperature, but not necessarily the temperature we feel on the ground. Snow forms when the atmospheric temperature is at or below freezing (0C or 32F). If the ground temperature is at or below freezing, the snow will reach the ground. However, the snow can still reach the ground when the ground temperature is above freezing if the conditions are just right. In this case, snowflakes will begin to melt as they reach this higher temperature layer; the melting creates evaporative cooling, which cools the air immediately around the snowflake. This cooling slows down melting. As a general rule, though, snow will not form if the ground temperature is at least 5C (41F).
Because snow formation requires moisture, very cold but very dry areas may rarely receive snow. Antarctica's Dry Valleys, for instance, form the largest ice-free portion of the continent. The Dry Valleys are quite cold but have very low humidity, and strong winds help wick any remaining moisture from the air. As a result, this extremely cold region receives little snow.
Snow is an accumulation of packed ice crystals, and the condition of the snowpack determines a variety of qualities, such as color, temperature, and water equivalent. As weather conditions change, the snowpack can change as well, and this affects the characteristics of the snow.
The character of the snow surface after a snowfall depends on the original form of the crystals and on the weather conditions present when the snow fell. For example, when a snowfall is accompanied by strong winds, the snow crystals are broken into smaller fragments that can become more densely packed. After a snowfall, snow may melt or evaporate, or it may persist for long periods. If snow persists on the ground, the texture, size, and shape of individual grains will change even while the snow temperature remains below freezing, or they may melt and refreeze over time, and will eventually become compressed by subsequent snowfalls.
Over the winter season, the snowpack typically accumulates and develops a complex layered structure made up of a variety of snow grains, reflecting the weather and climate conditions prevailing at the time of deposition as well as changes within the snow cover over time.
Generally, snow and ice present us with a uniformly white appearance. This is because visible light is white. Most all the visible light striking the snow or ice surface is reflected back without any particular preference for a single color. Most natural materials absorb some sunlight, which gives them their color. Clean snow, however, reflects most of the visible sunlight, creating a white appearance. How much sunlight the snowpack reflects to the atmosphere is characterized as snow's albedo.
However, snow may also appear blue. As light waves travel into the snow or ice, the ice grains scatter a large amount of light. If light travels over any distance, it must survive many such scattering events. That is, it must keep scattering and not be absorbed. The observer sees the light coming back from the near surface layers after it has been scattered or bounced off other snow grains only a few times, and it still appears white. The absorption is preferential: More red light is absorbed than blue. The difference in absorption is small, but is enough that over a considerable distance, say a meter (3.3 feet) or more, photons emerging from the snow layer tend to be made up of more blue light than red light. For instance, if you were to poke a hole in the snow and look down into the hole, you may see a bluish color. In each case, the blue light is the product of a relatively long travel path through the snow or ice. Think of the ice or snow layer as a filter. If it is only a centimeter (0.39 inches) thick, all the light makes it through, but if it is about one meter (3.3 feet) thick, mostly blue light makes it through.
Particles or organisms within the snowpack may also affect the color of the snow. Watermelon snow, for instance, appears red or pink. This coloration is caused by a form of cryophilic, or cold-loving, fresh-water algae that contain a bright red pigment. Watermelon snow is most common during the summertime in high alpine areas as well as along coastal polar regions. Although this snow may look candy-colored, it is not wise to eat it. Blood Falls, in Antarctica's Taylor Glacier, also has red snow, but for a different reason. There, the deep red color is caused by saltwater leaking from an ancient reservoir under the glacier. This water is rich in a form of iron that oxidizes when it comes into contact with the atmosphere, producing a bright red waterfall.
Dark-colored particles such as dust and soot can change snow's appearance and because they absorb more sunlight, hasten snow's retreat. Studies in the southwestern Colorado San Juan Mountains have shown that a layer of dust at the surface of a snowpack can shorten the duration of snow cover anywhere from 21 to 51 days. In contrast, an air temperature increase of 2 to 4C (4 to 7F) would shorten snow cover duration by only 5 to 18 days. Dust layers can become buried in the snowpack as new storms add clean snow on top, but these dust layers will emerge as the top layers melt away.