Sitka Nature

With clear weather prevailing in the days prior to and including the winter solstice, it was a good year for observing the sun during the time when the light and warmth we receive from it is a minimum. Many of the things I noticed this year were things I was vaguely aware of before, though I spent a some time trying to improve my understanding.

On the solstice, the sun rose in the southeast at 8:39 am, with sunset occuring in the southwest at 3:21pm, 6 hours and 42 minutes later. The locations of sunrise and sunset are basically 45 degrees south of due east and west respectively. The earliest sunset actually occured a week before solstice, when it was setting at 3:19pm. The two minute gain of afternoon light was more than made up for by five minutes lost in the morning, with sunrise on 14 December occuring at 8:34am, and on 21 December at 8:39am. The latest sunrise, 8:40am, occurs about a week after solstice. It is not until 4 January that the sun rises earlier than on the solstice.

The sun reaches its highest point in the sky when it is due south. This occured south at noon on the solstice when it was 9.6 degrees above the horizon. For comparison, on an equinox, it reaches a maximum of 33 degrees above the horizon with it passing 9.6 degrees at 8:25am and 5:55pm. On the summer solstice the maximum height is 56.5 degrees above the horizon and the equivalent height of winter solstice noon occurs at 5:45am and 8:20pm. The low height of the winter sun gives us long shadows when skies are clear, and the all too familiar dimly lit days when heavy clouds are overhead.

I made extensive use of this handy sunrise/sunset Calculator (which also includes sun altitude and the time when the sun is due south) for this post.

Recently I found out that Google Earth has added the ability view weather satellite imagery as a layer. Although I have found the satellite imagery for the northern Gulf of Alaska and Alaska before, looking at things on Google Earth makes it much easier to see the big picture as well as what is going on regionally.

For example, in the photo at the top of this post, notice the band of clouds stretching from near the equator all the way up into Southeast Alaska. The weather at this time was warm for the time of year, temperatures were in the low-to-mid 40s, and it was rainy. Looking at the weather pattern at the time, it seems likely this was due to warm air moving up from lower latitudes, cooling as it moved north, but still resulting in relatively warm temperatures.

Compare that to the current situation with clear skies and winds out of the north. Today’s satellite imagery shows the clear conditions prevailing over southeast and to the north. If you watch the 24-hour sequence of images (also available on Google Earth by clicking on the Weather > information layer), you can also see the clouds in motion.

It’s a fun thing to play with, and I suspect it will help my understanding of the regional weather as I compare what I see there with what I experience locally.

I was on O’Connell Bridge looking down into the channel when I noticed a large loon-looking bird that seemed much paler than I would have expected. It seemed to be favoring a spot near ANB Harbor, so I decided to go down and give it a shot. When I arrived down at the end of the dock, I saw that it was out in the middle of the channel. After waiting a few minutes, I was very grateful that the loon came up near where I was standing and let me take some photos. Probably best considered Rare in Winter in the Sitka area, this was the first Yellow-billed Loon I have seen.

Although Yellow-billed Loons are paler than Common Loons, this individual seems especially pale. This, in combination with strong patterning on the back suggests that it may be a juvenile, though I’m not positive about that.

For comparison, here is a Common Loon taken a few minutes earlier with similar lighting.