Suggestions Wanted

I’ve been doing some things on specific days of the week, and I’d like to extend that. What would you like to see? I think I’ve finally figured out how to put in tables, so this is what I have in mind:

Day of week	Topic
Sunday	Long topic (finishing horse color genetics)
Monday	North Pole Alaska Weather
Tuesday	Review? Guest?
Wednesday	Book Trivia
Thursday	Random?
Friday	Science and Health
Saturday	The Confederation

Sunday, Monday, and Wednesday would stay the same as what I’ve been doing, though the long topic posts have been more like weekend. Any comments on what you’d like to see? Reviews could include DVD’s as well as books.

If you see this on facebook, please go to the original blog to leave comments.

Of course the whole weekly thing will go out the window during the two weeks of Summer Arts Festival, when I’ll be turning the blog over to the Creative Writing students again.

North Pole Weather

It’s weather Monday again. Sunrise this morning was at 6:09 am and sunset will be at 9:34 pm, with civil twilight extending nearly an hour before and after the sunrise and sunset. The day is now 15 hours 25 minutes long, and we’re gaining 6 minutes 53 seconds a day. Driving light is actually almost 17 1/2 hours.

The snow is still melting pretty slowly, at least where it’s pristine enough to reflect the solar radiation back to space. It’s evaporating and melting internally, but the rate of disappearance is very dependent on the surface and the surroundings. The snow stake, in the middle of my south yard, shows 14″ of snow. The area just next to the south wall of my house is clear of snow. Snow on the north side of the house appears untouched in the shadow of the house, but is gone where sunshine can reach and the birch seeds and rose bushes have darkened it. Official snow depth at the airport is 17″. As I said last Friday, vegetation and exposure have an enormous impact on snow melt. It’s interesting also to note that low spots, where windborne seeds and dirt collect, melt faster. And I’m hoping my black compost barrel will get warm enough in the sun to get the composing process started even with snow still on the ground.

It’s slightly cool for this time of year, and the forecast for the next few days is basically more of the same. Highs around 40, lows in the low 20’s, and no precipitation. April is our driest — and muddiest — month, with precipitation slowly increasing until we reach a peak in August. This April so far we’ve had 1.7 inches of dry, fluffy snow — .07″ of water equivalent. It’s still too early to tell what the effects of the rain last November will be, but at least most of the ice is gone from the roads. Mud, however, is starting to appear wherever the snow is gone.

The Leopard Gene in Horses 4

Not all horses with the leopard gene have blankets of any size, and not all have spots. The gene can also produce two specific types of roaning, called frost and snowflake.

These roan patterns are quite separate from that produced by the roan gene, which becomes less prominent with age and leaves head, legs, mane and tail dark. The leopard gene produces horses which are normally colored or at most have a few white hairs over the rump at birth, but develop roaning (frost) or scattered white spots (snowflake) as they age. In contrast to grey, the pattern eventually stabilizes rather than producing a pure white horse.

In frost, the roaning tends to be most prominent over the hips. So-called varnish marks are common — areas where the bones are close to the surface, such as the hipbones and nasal bones, retain pigment while the rest of the coat is roaned. An aged varnish roan may be almost white except for these varnish marks.

Snowflakes are small white spots scattered randomly over the body, but often most numerous and prominent on the front part of the horse. They tend to become larger and more numerous with age, until in extreme cases the horse appears white with colored specks. This gives what is often called a speckled pattern, not to be confused with flea-bitten grey. Note that not all of the photos shown at the link are true snowflakes — the term is used very loosely.

Both types of roan may be combined with any of the blanket or spotting patterns, or may occur alone. Figure 8.140 in Sponenberg is a beautiful example of a combination of snowflake, varnish roan, blanket and leopard spotting all on the same horse. (Put Figure 8.140 on the search inside field.) Since the leopard gene can produce any of these effects, alone or in combination, breeding leopard-pattern horses can lead to some interesting results.

The remaining named horse in Tourist Trap, Amber’s mount Splash, is a bay varnish roan with a small spotted blanket, in color rather like the horse in Figure 8.141. He’s a gelding, about 14.1 hands – just enough smaller than the other four to have problems with fords. Roi has seen only solid colored horses on Central, and his first look at Splash gives this impression:

“Amber’s [horse], a little bay roan with curious dark lines on its nose, looked less exotic until it turned as she halted it.  Then it became apparent that it had a large white area, punctuated by dark bay spots, over its hips.”

I may summarize the equine color loci and alleles next week with links back to where they are mentioned, but I have covered most of the known color genes in horses. That doesn’t mean more won’t be found!

Breakup

I enjoy breakup. Oh, not the puddles, or the mud, or having to wear waterproof boots to get anywhere. And some of those puddles are deep, especially in areas which should be drained by culverts. The highway department does a lot of steam thawing this time of year, as the culverts don’t thaw without help. But it’s fun to watch how the breakup takes place.

Breakup happens early if there is a building nearby. The sun heats the structure, and the structure radiates that heat onto the snow. The thermal radiation is in wavelengths the snow can absorb — unlike the sunshine, which the snow just reflects away. All of these photos were taken today, when I still have 15″ of unmelted (and pristine-looking) snow in my back yard, which is on the south side of the house and fully exposed to the sun. The building is the University of Alaska Fairbanks Museum, and the ground immediately around it is clear of snow.

The same can hardly be said of the snow across the street. The sun is striking this area from the right of the picture, and you can see some melting from the gravel that has been plowed from the road. But the gravel also actually protects the snow from melting if it is thick enough.

The end of my gravel road next to the pavement is thawing rapidly. It’s been plowed often enough that gravel is poking through the packed snow, and this end is more exposed to the sun. With the gravel darkening the snow, it’s starting to melt, so breakup is starting at this end. Getting my mail will be a real problem without boots.

The thawing doesn’t extend to the whole length of the road, though. Here, at the end of my driveway, the snow is still clean enough to reflect most of the incoming sunlight back to space, and very little melting has taken place.  From past experience, I know that the thawing at the end of the road will progress this way, though.

What about trees? Birch trees drop their seeds in spring, darkening the snow around them. As a result, the ground under birches, with little shade from the bare branches, thaws early. Open birch forest is one of the first natural areas to thaw. The rose bushes on the left of the picture are almost as early — they poke through the snow enough that the snow can warm the branches, which then radiate heat to the snow around them. Spruce trees shade the snow around them, and snow lasts longest in spruce forest. It seems like such a little thing, but it may make a week’s difference in how long before the ground is bare — and bare ground is far more efficient than snow at absorbing the heat from the sun.

How High the Moon?

The waxing moon is shining in my window at night, now, but it is lower on the horizon every day. I don’t mean it’s later when I go to bed; I mean that the moon follows a lower arc in the sky every night, even as it becomes fuller. What’s going on?

Waxing gibbous moon, looking south before sunset April 14.

I’ve done a good deal of talking about the sun being lower each day in the sky until the winter solstice. Since then the sun has been higher in the sky each day, though it’s still only 35 degrees above the horizon at noon, and will never go above 48.6 degrees here at 64 degrees 50 minutes north. But what about the moon?

The moon goes around the earth  approximately in the same plane the earth goes around the sun. (We’ll get to the “approximately” later.) That means that when the moon is full, it is opposite the sun in the sky. If the sun is way below the horizon at solar midnight, as it is around the winter solstice, the full moon will be high in the sky. In fact, it will follow nearly the same path on the winter solstice as the sun follows on the summer solstice. On the summer solstice, the full moon will barely peek above the southern horizon.

The new moon, on the other hand, is in nearly the same place in the sky as the sun. The new moon will follow approximately the same path as the sun. The new moon will be very low in the sky in winter, and very high in the summer.

What about other phases? Right now the moon is waxing gibbous — that is, it is between first quarter (when it looks like a half circle in the sky) and full. On April 14 its highest altitude was 26.5 degrees; tomorrow it will be 20.3 degrees. Effectively, it is following the same path as the sun did in mid-March. I won’t even try to go through the mathematics and geometry involved, but for practical purposes the waxing moon is highest in spring, with the first quarter being highest near the vernal equinox (northward equinox, on the Confederation calendar) and the third quarter being lowest. In fall, this is reversed, with the waning moon being higher in the sky.

Up until now, we’ve been assuming that the moon’s orbit is in the same plane as the Earth’s. If that were really true, we’d have two eclipses — one lunar and one solar –each month. In fact, the moon’s orbit is slightly inclined to the ecliptic — about 5 degrees, to be exact. The direction of the inclination changes due to the pull of the earth’s equatorial bulge, which causes the plane of the orbit to precess with a period of 18.6 years. The inclination of the orbit makes the moon appear to move slightly above the sun’s path in the sky for half a lunar cycle, and slightly below it for the other half. Which part of the cycle depends on time of year and where the moon is in its precession cycle, but it is possible for the moon to be circumpolar or to remain entirely below the horizon here in the Fairbanks area, even though we are south of the Arctic Circle.

Right now, eclipses are near the solstices, so we won’t see the full moon stay below the horizon all night in summer, or be above the horizon at solar noon in the winter — though I’ve seen it in other years.

Gaudy Night

All of the Sayers quotes for this week were from a single book, Gaudy Night. I didn’t plan it that way; I was looking for the quote about the chessmen and was overwhelmed by twitter-sized quotes. So I just stuck with the one book, close to the last of the books about Lord Peter, and in fact close to the end of Dorothy Sayers’ mystery writing career.

Dorothy Sayers was a Christian scholar, one of the first women to receive a degree from Oxford, and the story is set in a fictitious women’s college in that University. Lord Peter has been wooing Harriet (a mystery writer) ever since her first appearance in Strong Poison, and she also played a pivotal role in Have His Carcase. This book is as much a romance as a mystery.

Thursday: “The first thing a principle does is to kill somebody.” One of the things Lord Peter says to Harriet that she later recalls when she is realizing that he doesn’t want static stability.

Friday: “The confidante has a very heavy and thankless task.” Harriet to Miss Briggs, who has been trying to cope with Violet Cattermole’s problems.

Saturday: “This goes to prove that even minor poetry may have its practical purposes.” Harriet has jotted down the first eight lines of a sonnet in her notebook of the case, simply because it was the only paper immediately to hand when the lines came into her head. Later, when Lord Peter returns the notebook, he has added the sestet. The completed sonnet reads:

“Here then at home, by no more storms distrest,
Folding laborious hands we sit, wings furled.
Here in close perfume lies the rose-leaf curled,
Here the sun stands and knows not east or west.
Here no tide runs; we have come, last and best,
From the wide zone in dizzying circles hurled
To that still center where the spinning world
Sleeps on its axis, to the heart of rest.

“Lay on thy whips, O Love, that we upright
Poised on the perilous point, in no lax bed
May sleep, as tension at the verberant core
Of music sleeps; for if thou spare to smite,
Staggering, we stoop, stooping, fall dumb and dead,
And dying so, sleep our sweet sleep no more.”

Again, the part Lord Peter has added gives Harriet insight into his character. Challenge to the reader—find the definition of “verberant.” (Yes, it is a word.)

Sunday: “I loved them, and you gave them to me.” Harriet to Peter, when the carved ivory chessmen he gave her are destroyed. His response: “‘You gave them to me, and I loved them’ is all right, but ‘I loved them, and you gave them to me’ is irreparable.”

Monday: “What would that matter, if it made a good book?” Lord Peter to Harriet, after suggesting some changes to make one of her characters more human. (The suggested changes would require that (1) the whole book be rewritten, and (2) Harriet bare her soul to a degree she has been avoiding ever since being tried for murder.)

Tuesday: “The protective male? He was being about as protective as a can-opener.” Harriet’s response to Lord Peter’s suggestion.

Wednesday: “Guiltily, he reached for the damaged tissues and began Healing the injury.” Bowling. From Homecoming. Snowy has been conditioned from birth that his odd talents are both wrong and could get him killed if anyone found out about them.

Next week I’ll go back to random science fiction and fantasy, though I may use classics or other genres in the future.

Twilight

No, it’s not about the books. But yesterday I mentioned that we no longer have astronomical night, and I felt that some definitions were in order.

End of civil twilight, available light photo looking NNW at 10:10 pm last night.

Twilight is defined as the period between the first traces of scattered light in the sky and sunrise, and between sunset and total darkness (other than starlight and moonlight.) It is actually divided into three periods each in the morning and evening, with boundaries determined by how far the sun is below the horizon.

Civil twilight is the period between the sun being on the horizon (sunrise and sunset) and the sun being 6 degrees below the horizon. If the sky is clear and you have good vision, you can generally see well enough to drive without lights, though your car will certainly be more visible to others if you turn your headlights on. The brightest stars and planets become visible after sunset and fade out before sunrise during civil twilight, but it’s not a very good time for even casual astronomy, except for watching the new moon, Venus and Mercury. Local laws generally define the limit of civil twilight using the time (30 minutes before sunrise and after sunset, for instance) but that can be very far off at high latitudes. Here in Fairbanks, for instance, it never gets darker than civil twilight from May 27 to July 28.

Nautical twilight is the period when the sun is 6 degrees to 12 degrees below the horizon. It was originally defined as the time when it was possible for sailors to make star sights, as most of the stars were visible but so was the horizon at sea. Here in Fairbanks it never gets darker than nautical twilight from April 26 (two weeks from now!) to August 18.

Astronomical twilight is defined as the period when the sun is 12 degrees to 18 degrees below the horizon. Ideally, when the sun is more than 18 degrees below the horizon 6^th magnitude stars should be visible. Sadly, this is no longer true anywhere in the vicinity of city lights, and in most places the difference between astronomical twilight and civil twilight is imperceptible. Here in Fairbanks, it does not get darker than astronomical twilight from April 9 to September 4. City lights are not a great problem up here, but aside from a brief period in September good astronomical viewing coincides with temperatures far too low for comfortable star gazing.

Twilight is very short at the equator, where the sun sinks or rises vertically at a rate of 15 degrees an hour . This gives only 24 minutes for each stage of twilight. Sunsets and sunrises seem very abrupt. At higher latitudes the sun seems to slant down to (or up from) the horizon, and twilight (and sunrise and sunset colors) can last much longer. I’ve tried to incorporate this in Homecoming — the sunsets and sunrises are very short on Marna’s tropical island, for instance.

North Pole Weather, April 11

Sunrise at 6:31 am, sunset at 9:15 pm for 14 hours and 44 minutes of daylight. We’re now gaining about 6 min 50 sec a day, and we’ve lost astronomical night–the sun is less than 18 degrees below the horizon at solar midnight. By the end of the month we’ll have lost nautical night as well–the sun will never dip more than 12 degrees below the horizon. The snow is melting internally, though the water is still mostly refreezing within the snow pack. Visually, it’s only settling–but the snow stake now shows only 16″ on the ground.

Northwest corner of roof

Icicles  are beginning to form on the north corners of the roof.

Where snow has been plowed up and has dirt incorporated near the surface, it’s starting to look grimy. The paved roads are now pretty much ice free, except where snow melt runs over them in the daytime and then freezes at night. The highway department does a pretty good job of keeping the snow berms on main roads plowed back so they are below the level of the pavement, but minor roads and graveled roads are still a problem.  Snow on the gravel road I live on has barely started to melt.

End of my driveway, snowing dirt coming to the surface as the piled snow melts.

Next week? Based on climate history, the average daily temperature should now be above freezing. The forecast is less hopeful–daily highs in the low 30’s (if that high) until the weekend, when we might get some highs near 40 and lows around 20. The snow should continue to settle and the dirty snow will become more prominent, but I don’t expect major runoff until it warms up. No snow in the forecast, and this time of year it would only delay melting.

Since I don’t ski, it’s good weather to do the final editing on Tourist Trap!

The Leopard Gene in Horses Part 3

Not all horses with white markings produced by the Leopard gene are leopards. The white markings are generally symmetrical and present at birth, but they vary a great deal from horse to horse and may even be absent entirely. The minimal expression is white over the top of the rump, and the broad term for the pattern is blanket.

Edges of the white blanket may be crisp, flecked or roaned.

Sponenberger divides the white patterns by percent of white at birth. The modification I am using in Tourist Trap is:

10% or less	white spots over hips
10% to 20%	lace blanket
20% to 40%	hip blanket
40% to 60%	body blanket
60% to 80%	near leopard
90% to 100%	leopard

Note that “leopard” in this table includes both leopard and few-spot leopard, and that the size of the blanket has nothing to do with whether spots are present. If one copy of the leopard allele and one of the wild-type allele are present, whatever white areas are on the horse will normally have spots of the base color. If two copies of the leopard allele are present, the white markings will have few or no spots, and the pattern is often called snowcap or few-spot.

The Pattern-1 gene is heavily implicated in the amount of white, but it is almost certainly not the only modifier.

Spots will normally be of the base color, but may show a concentration or dilution of color. Thus they may appear darker or lighter that the base color.

The description of Roi’s horse, Raindrop, in Tourist Trap is that of a body-blanketed grulla approaching a near-leopard. She has white coronets and spots significantly darker than most of her body, which is already dark for a grulla. Roi’s first sight of her gives the following description:

“One of the two led horses had a black-spotted white body, but its neck, legs and chest were a dark mouse gray, set off by a black head and mane and a black and white tail.” Raindrop is later referred to as having a sparse mane (black) and being the color of polished slate. The dark dorsal stripe typical of duns would have been in the white-blanketed area, and hence invisible.

Genetically, she would have had two recessive black alleles at the Agouti locus, at least one wild-type allele at the Extension locus, at least one dun allele at the Dun locus, and one leopard and one wild-type allele at the TRPM1 locus.

Next week I’ll talk about the roan, flecked and snowflake patterns produced by the Leopard gene. Again, these patterns are often called Appaloosa in the United States, but they occur in horses worldwide.

When it’s Springtime in Alaska…

April showers bring May flowers? Not in Interior Alaska, where showers in April are as likely as not to be snow showers, and precipitation of any kind normally falls on top of the slowly melting winter snow pack.

Statistically, April is our driest month, with only .29″ of precipitation. Snow has the effect of brightening the snow pack and reflecting back more of the growing solar radiation to space, so we’d really just as soon do without it. Unfortunately, we don’t have much choice. Last night we got about an inch of fresh snow, and it’s warm enough (near freezing) that the roads will be very slippery. It should melt off of dark surfaces fairly fast, but where it’s fallen on the existing 18″ snow pack it may take a day or so.  I’ll need to brush off the dark compost tumbler again so the sun can get to it.

Taken from my front porch, about an hour and a half after the picture on the right side. There is actually a road among the trees just beyond the big spruce, though it's rather hard to see.

It looks attractive enough. Much of the snowfall was not accompanied by wind, so the snow it sitting prettily on top of individual branches. Since I took the photo out of my office window the sky has begun to clear, and weak sunlight is touching the trees. But at this time of year, all we really want is for the snow to go away!