Sunday, January 23, 2011

Sundogs on a Brilliant, Bitterly Cold Day

Two sundogs greeted us this morning when we looked out the window. It had plunged to about -26 overnight, and the air was crisp and cold, but not a cloud in the sky, a brilliant winter morning. There was a slight haze though, as if tiny frost crystals were floating through the air; you could actually see them sparkling as they drifted around.

Then I saw the sundogs, bright flares shining on either side of the morning sun, for awhile after 9 a.m. (and perhaps earlier).

Later I headed for the Internet and learned that sundogs are caused by tiny hexagonal ice crystals, either at high altitudes in cirrus clouds, or floating in the lower atmosphere as 'diamond dust' - this is what I think we had this morning. The crystals float horizontally, like tiny hexagonal dinner plates, drifting to the ground like a leaf in the fall, and reflect the light at a 22 degree angle, causing the bright rainbow-like flares, 22 degrees out on either side of the sun. The sundog colours range from red nearest the sun to blue on the outside. These two pictures show the left and right sundogs, with the reddish colour nearest the sun in each case.

Larger crystals develop more wobble as they fall, generating a taller sundog, which is how I would describe these. In the right hand sundog you can actually see the faint reddish colour extending up and down, almost forming part of a more complete halo around the sun. Today I guess we had large diamond dust in the air!

Thanks to Wikipedia, The Weather Doctor and Atmospheric Optics for what I've learned about sundogs today!

Interestingly, The Weather Doctor refers also to atmospheric crystals forming in hexagonal rod shapes, much like a pencil, in other situations. I've observed that melting ice in a pond also forms pencil-like rod shapes. In those 24 to 48 hours between being solid and vanishing in early spring, pond ice forms vertical pencil-like rods of ice that will fall apart in your hand before melting altogether.

Thursday, January 20, 2011

Sunny Days!

Two or three glorious sunny days earlier this week, and we got out snowshoeing to enjoy it - deep powder snow that let you sink in a long way even with snowshoes. The bright sun on the white snow reflected a million sparkles beneath the cobalt blue sky. The camera simply doesn't do it justice.

One day we walked down a concession road that lies buried in snow, unused but by snowshoers and snowmobiles in the winter. Another day I snowshoed through the nearby back woods and along the fencerow on the edge of the back field, leaving a strange track of snowshoe and pole prints. I use an old pair of ski poles for snowshoeing.

The old snowshoe tracks someone had left earlier were the only mark across the unbroken field of snow until I arrived - now partly drifted in as if they were left by a ghost. On the north boundary of the field, the old drystone walls, four feet high, were completely buried in fresh snow. We carried on, the dog gallumphing through the deep snow and getting completely exhausted, until we reached the huge broken stump of the old maple, silhouetted against the brilliant blue sky, before heading for home.

Saturday, January 15, 2011

New Rockfall on the Cliff?

Driving out to Kimberly, the village in the bottom of the valley a few weeks ago, I looked up at the cliff, and there seemed to be a new rocky scar where none existed before.

I've looked more closely now, and it appears to be a large new rockfall on the edge of the Niagara Escarpment cliff. The picture clearly shows the older cliff outcrops, weathered to a dirty grey, on the right, and a new lighter coloured rock scar on the left.

A close look at this clearly shows it is a place where part of the cliff has collapsed. There are vertical crevice caves along this area, and I've heard stories locally of youngsters going to explore the caves along here in the past. This is something I'll need to investigate when spring comes! A good excuse to get out exploring.

Meanwhile, it's been snowing like mad all day today. An 'Alberta clipper' as the meteorologists call it, passed through, leaving about 8 inches of fresh powder snow. You could see the storm had passed on the radar, so I went out and blew out the driveway. But then the lake effect snow started, emerging out of nowhere on the radar, and continuing. We are a very long way past the forecast of 2-5 cm.!

Thursday, January 13, 2011

Signs of Changing Seasons!

I couldn't bring myself to say 'Signs of Spring', especially after a night of 17 below zero temperatures, but never-the-less, there are always signs of the changing seasons.

The first was the chickadee calling. Everyone knows the chickadee's typical song, 'chickadee-dee-dee', but perhaps you don't know their spring mating call, which you hear frequently as spring approaches. I'm told by reputable naturalists that it sounds like 'hamburg-urr', with the last two syllables falling. Anyway, we first heard it over a week ago, when January had hardly started, and we're hearing it regularly now on sunny days - the birds know that spring is on its way.

Then there's the lengthening days. I often walk the dog in late afternoon, and for a few days before Christmas you really had to be back home by 5 p.m. to escape the dark. But now you can leave on a walk at 5, and it will be still light out when you arrive back at 5.30. A full half hour of extra daylight already!

Finally, there were the two wonderful sunny days earlier this week - great days to be out snowshoeing or skiing, which we were. Although it was bitterly cold overnight, in the hours after lunch when the sun was shining, you could certainly feel the heat of that sun on your face, and it was melting the ice off the porch. A beautiful day to be out.

Wednesday, January 5, 2011

Water and Wetland Recharge in the Winter

Most rural landowners and all farmers have a good idea of how important groundwater recharge is to replenish the water table every year. When you're dependent on a well for drinking water, this is pretty important. We likely associate the water recharge with the spring melt in April, when all the streams flow high, the ground is often soggy, and water is percolating into the ground.What we may not realize is that this also happens during a winter thaw. The streams run high then too, if only briefly, and water is sinking into the ground, recharging the water table and any nearby wetlands.Rural ponds show the same pattern, the water level often dropping over the summer, but rising again in the winter. Through my own observation I've learned that rural ponds often regain their high water level during winter thaws rather than in the spring melt - indeed, by the time the spring melt happens, the pond has already risen to the high water level of last year.After last week's two-day thaw, water recharge around the valley was obvious, especially in the wetlands, a clear illustration on the surface of unseen groundwater recharge going on beneath the surface too.

Monday, January 3, 2011

Creeks and Rivers are Running High after the Thaw

The Beaver River

The big two-day thaw left us with a lot less snow, and a lot more run-off. The Beaver River is running very high, over it's banks in places, and slightly muddy. Even at normal water levels, the river braids into 2 or 3 different channels in the flat parts of the valley bottom; today it is filling all those channels and flowing among the trees in between.

Wodehouse Creek

All the smaller creeks are overflowing their banks too, with a strong current carrying the water along the channel. All the melted snow is headed downstream. You expect this in late March or early April, during spring run-off, but sometimes we forget it happens in a winter thaw too.

Rivulet South of Kimberly

And then there are the tiny ephemeral streams that usually don't exist at all, unless perhaps as a tiny muddy channel that you need to step over after a summer rain. Today they are all flowing with run-off, this one blocking the trail through the old meadow where it spreads out along the old tractor ruts. A few colder days and this stream will disappear entirely, letting you walk the trails easily again.

By the way, the temperature did plunge on Saturday, about 10 degrees in 10 hours, and the wind did shift around from the south to the northwest. Winter is back, with a little new snow to cover the dirt exposed by the thaw.