You'd think the answer would be quite simple: What time does the sun set at the South Pole on the equinox?

In a perfect world, the sun would be exactly half-way down the horizon at both poles at the moment of equinox -- which is 10:32 a.m. our time on Saturday. For the South Pole, it's the first time the sun is attempting to set since late September. For the North Pole, it's the first hello to the sun since then.

But the answer is not that simple. Actually, I'd say it's not even somewhat complex -- it's *really* complex.

Dr. Dale Ireland -- he of the great time lapse camera over in Silverdale that we feature frequently here -- has a friend who is at the South Pole working on the CUBE neutrino detector down there. They received an e-mail from a NOAA worker detailing just how difficult it is to figure out just when the sun is actually going to disappear and not return.

The short version: we make a lot of assumptions based on ideal conditions that are rarely ideal. For one, the Earth is not a perfect sphere. Two, official sunset is calculated when the sun drops below the horizon, as in all the way, not just half way. Third, and most importantly, is how changes in the atmosphere can affect how the sun appears.

These atmospheric effects make figuring the actual time the sun appears to set below the horizon to someone standing at the pole quite variable from year to year, and makes it a guessing game for those down there when the sun will appear to disappear.

Some specifics of the math involved: Based on the sun's size, it takes about an extra 16 hours at the South Pole for the sun to go from "half gone" to "all gone" below the horizon. (Remember, the sun is still travelling horizontally around the horizon as the day progresses. We're talking vertical movement there). Also, the atmosphere bends lights and the degree of refraction is related to the thickness of the atmosphere. But this effect is seen worldwide -- the sun actually sets a few minutes before you actually see it set. At the South Pole though, the air is so cold and dense that it nearly cancels out the thinness from their elevation.

Anyway, they figure this refractive effect is good for another 36 hours of keeping the sun appearing above the horizon (even though it's not really there).

Also a part in the madness -- how tall you are, and the elevation of where you are standing, and where the sun will actually be on the horizon when it finally sets. Since there's all these other factors in play for what time the sun will set, they don't know where on the horizon it will finally set, so variations in topography could affect the sun's disappearance time -- if it sets behind a "hill", that'll make it disappear earlier than if it sets behind a minor valley. (Yes, there are some minor topography variations at the South Pole.) The e-mailer says this can add anywhere from 0-10 hours to the sunset time.

All in all, they figure the sun will finally set there -- sometime between 2:30 p.m. and 10:30 p.m. our time on *Monday*.

OK, that was the "short version". If you want the long version, I have copied the entire e-mail onto this web page. He also has some great photos of the sunset and "Green Flash" which is actually the "Blue Flash" down there. I've pasted some of the images below here as well.

 

Apparently, these clouds are getting quite trendy.

The Wenatchee World Monday picked up on a photo submitted to the Spokane office of the National Weather Service on Feb. 28 that show these mysterious clouds hovering just to the west of the city.

These clouds are called "hole punch" clouds and the prevailing theory is that they are created when an airplane descends or ascends through a stable cloud layer, causing a visible rift.

The NWS site even has satellite images taken at the time and you can see two little "Swiss cheese" type-holes in the image.

These clouds have been in the news recently, with a hole punch cloud spotted in Russia last October getting a lot of media attention.

And then, a short while later, a similar cloud popped up in Romania

I can hear the snowbirds from up here who are down in Arizona this winter from here: "Why did we bother?"

It's not often Seattle's weather can be compared with Phoenix, but this El Nino winter has turned the desert into a virtual Seattle clone.

I received a note from frequent blog contributor Mark Albright (a research meteorologist at the UW) who has been down in the Phoenix area for a while. He says that five of the past seven weekends down there have featured rain. Or as we call it up here: "Typical weekend weather for months that end in 'r', 'y', 'h', 'l', 'e', and 't.' "

With that note, I was eager to crunch the data and muse that the past seven weekends in Seattle have been nicer here than there. But before they start erecting Space Needles and we plow over the arboretum to make way for cacti, it turns out that while they have tried to mimic our weather, even with our mild El Nino pattern, we have still out-Seattle'd them.

While it has rained at some point on five of the past seven weekends in Phoenix, it's rained on the past six of seven here. (Our lone exception? The Sunniest weekend EVER!...(Ever...ever...ever...))

Of the 14 weekend days, it's been soggy for 7 of them in Phoenix, but 10 in Seattle. Accumulated rain: Phoenix had 1.51" while Seattle checked in at 1.75". Phoenix did get the honor for wettest weekend day (0.70" on Feb. 28 versus 0.42" on Feb. 14 for us).

But in just about every other category, we "win" -- we even "out-clouded" them, with average sky cover at 54% for Phoenix but 67% for Seattle.

And then, of course, the real reason why people flee here for winters in the desert: Average high temperature in Seattle during those seven weekends? 52.6 degrees. Phoenix? 66.8 degrees.

So, I guess that means the flora in the arboretum can breathe easier? :)

After weeks of a springlike winter, winter returned at the buzzer, punctuated by some spots of snow on Monday followed by the coldest night we've seen since mid-December.

And if you were one of many who woke up only to have to dig out your ice scraper amid mutters of  "Geez, just how cold is it this morning?", we've got you covered.

For Seattle, the mercury dipped to 28 degrees, which tied the record low set in 1956.

Here are a list of other cities' low temperatures:

• Bellingham: 27
• Friday Harbor: 28
• Mount Vernon: 30
• Oak Harbor: 29
• Port Angeles: 30
• Arlington: 25
• Everett: 31
• Seattle (UW): 32
• Seattle (Boeing Field): 29
• Seattle (Sea-Tac): 28
• Renton: 30
• North Bend: 27
• Gig Harbor: 29
• Tacoma: 25
• Olympia: 23
• Bremerton: 25
• Shelton: 24
• Forks: 33
• Hoquiam: 32

 

The spits of snow here and there across the southern Puget Sound area Monday morning was due in part to a weak Puget Sound Convergence Zone.

Here is a great time lapse video of the event, courtesy of Dr. Dale Ireland's web camera over in Silverdale:

Notice how the southerly and northerly winds battle it out right over the Hood Canal.

Normally, the Convergence Zone's playground is farther north, but today, it the northerly wind component was a bit stronger, keeping the zone down south.

You can read more about the morning snow and how it's not quite time to dust off the snow panic manual, in my article on the main news site page.

WASHINGTON (AP) - The beleaguered global warming panel has found an outside group to review how it writes its reports.

An international group, the InterAcademy Council, will be given complete control to review the rules, procedures and reports of the Intergovernmental Panel on Climate Change, said a scientist close to the situation. Recently, several unsettling errors have been found in the climate panel reports issued in 2007.

Though the mistakes don't undercut the broad consensus on global warning, they have shaken the credibility of climate scientists and given skeptics of global warming ammunition.

The InterAcademy Council is a Netherlands-based organization of the science academies of 15 nations. "They will run the review themselves," said a scientist close to the situation, who asked not to be named because the researcher was not authorized to talk publicly. "It will be independent... They are choosing the reviewers."

The idea is to have the review finished before the annual meeting of the IPCC in October, the source said. The climate panel was formed by the United Nations and the World Meteorological Organization.

It will be up to the InterAcademy Council to decide if it's acceptable for its reviewers to have taken part in past IPCC reports. A large number of top climate scientists have participated in the IPCC. The council will also look at whether the reports should include non-peer-reviewed "gray literature" often written by governments or advocacy groups, the source said.

The reviewers will also look at whether to put in procedures that could catch and correct errors better, the source said.

Details of the review will be announced Wednesday at the United Nations, after the IPCC chairman meets with United Nations Secretary General Ban Ki-Moon. The IPCC had been looking for an outside group to do the review.

The UN secretary general himself is requesting the review as well as the IPCC, another source close to the situation said.

"It's to be welcomed," said IPCC co-author and Princeton University professor Michael Oppenheimer. "It's a step in the direction of re-establishing the IPCC's credibility with the general public. I, as an IPCC scientist, welcome this kind of check on things."

The IPCC, which is mostly a collection of scientists volunteering their work, produced reports that had errors that ranged from mistaking how much of the Netherlands is below sea level to botching how fast glaciers in the Himalayans are expected to melt.

Sen. James Inhofe, R-Okla., last month called problems with the IPCC "the makings of a major scientific scandal."

Stanford scientist Stephen Schneider, another IPCC co-author, called independent review a great idea.

"Everybody knows there's a tiny error rate," Schneider said. "Any error rate that can be fixed should be fixed."

The IPCC shared the Nobel Peace Prize in 2007 with former Vice President Al Gore.

Wade B. Clark snapped this gorgeous shot of a very interesting halo around the sun Friday morning from Sedro-Woolley.

It shows a 22 degree halo around the sun, two sundogs (one to the left and one to the right), a sun pillar, and an upper tangent arc.

We can thank the tiny ice crystals in the high clouds around this morning for generating the effect. Check out more on how these form at www.atoptics.co.uk.

And have a great weekend!