The word Analemma sounds like a girl’s name or perhaps an exotic fruit but in fact it’s the name for that figure 8 hanging in the sky above. You won’t see it in Nature but you may have seen it as a symbol printed on an old-fashioned globe of the world.
Technically speaking an analemma is the location of one celestial body as viewed from another for one complete orbit. Practically speaking it’s the Sun’s position throughout the year at the same location and time of day on Earth. I was surprised to learn it’s a figure 8 but that’s because the Earth’s orbit is elliptical and tilted.
This photo took a whole year to create. Every other week in 1998-1999, Jack Fishburn took a photograph of the sun’s position from his office window at Bell Labs. He was careful to place the camera in the exact same position and snap the photo at the same time of day (correcting back to Standard Time during Daylight Savings). After collecting a year of photographs he overlaid them to create the analemma.
Tunc Tezel did the same thing at Baku, Azerbaijan and made it a movie here.
You can create your own analemma if you’re persistent (one whole year) and precise (same camera location and time of day for every photo) and have access to Photoshop.
When you’re done you’ll know that the top of the 8 is the summer (northern) solstice, the bottom is the winter (southern) solstice, and the crossover point is both equinoxes. Today, one day after the Northern Equinox, the sun is very near the center of the analemma.
(photo by Jack Fishburn via Wikipedia GNU Free License. Click on the image to see the original)
Yesterday more than three inches of wet snow fell across Pittsburgh. Sometimes it changed to rain. Overnight it froze.
Expecting dangerous footing, I put on my ice cleats and went out to see.
Under light snow on the sidewalk … Viola, a glacier!
That’s not all. Last night I noticed that my car, parked on the street, was standing in three inches of water because ice dams prevented the water from draining. In the dark I heaved snow and water to the storm drain, hoping to prevent my tires from being locked in ice this morning. What do you think? Am I stuck?
I spread salt and came indoors, feeling a little smug that my ice cleats worked so well.
But the ice has one more trick up its sleeve.
(all photos by Kate St. John, except the ice warning sign in Montreal is by Paul Joseph via Wikimedia Commons. Click on the sign to see its original)
In western Pennsylvania, flood warnings have been issued for Armstrong and Clarion counties due to an ice jam that is blocking the Allegheny River, creating a backflow of water into Parker, according to an AP report. The warning is in effect until 7 a.m. Thursday. State Route 268 has been flooded and at least two people have been rescued from the floodwaters in Parker.
In February 2009 I was hiking at Raccoon Creek Wildflower Reserve when the ice broke and jammed in front of me. Click here or on the gray-brown ice photo for my in-person (Throw Back Thursday) report.
(photos by Kate St. John: Ice and gulls on the Monongahela River at Duck Hollow, 25 Feb 2015. Ice on Raccoon Creek, 8 Feb 2009)
We were lucky. In an uncanny space-time coincidence a very big meteor whooshed over Russia two years and two days before the Kittanning event. It weighed 10,000 tons(*) and injured over 1,000 people. February 15, 2013 in Russia. February 17, 2015 in Pittsburgh.
…What is it about February?
I wish I had seen it. I was awake but I wasn’t paying attention.
(YouTube video of the February 17 fireball from NASA’s Marshall Center)
(*) that’s 40,000 times heavier than the meteor at Kittanning.
Yo! Did you know that Jupiter’s moon Io is the most volcanically active world in the solar system?
Io is the size of our Moon but a very inhospitable place. It’s covered in sulfur which makes pretty shades of yellow but unbreathable air.
To make matters worse, Io is so small and Jupiter is so large that Jupiter’s gravity causes 100 meter land-tides on Io’s surface. Yes, the land rises and falls 330 feet as Io orbits Jupiter. No wonder Io has more than 400 active volcanoes!
In 2007 NASA’s New Horizons spacecraft took photos of a plume coming off the top of Io. What was it? A volcanic eruption rising 300 miles above Io’s surface!
Click on the screenshot above (or click here) to see a video of Io in action.
Even after the coldest winter the east-central U.S. can remember, the average U.S. temperature was 0.5 degrees above normal. (Ask Westerners how hot they were!) Here’s a month-to-month video that shows that even the East was hot in December.
Climate scientists agree(*) that the warming is caused by humans and there will be sobering results. We’ve caused it. We record it. We report on it. But will the news change anything?
On a political and media level in the U.S. this news has generated interest and talk but no real action. On the natural level — among the air, water, birds, plants, and animals that I care about — it is big news and they’re doing something about it. The air is hotter, the ice is melting, the sea is rising, and the plants, animals and birds are moving north or uphill.
Humans are doing something too, even here in the U.S. where our society has not taken up the cause.