Thursday, December 22, 2011

Solstice 2011 at Pole

I am making posts out of order trying to get the current events current, namely Solstice for the moment.

Often being from Alaska people I meet ask me if it is always light/dark out all the time?  Sometimes they will have 6 months in there. I spell out the dynamic changes in daylight in detail giving them a $50 answer when they probably wanted a 50 cent one.  But that is what you get when you ask me a question so be prepared. 

At the South (and North, of course) pole you do get almost exactly 6 months of day and 6 months of night with sunset/rise lasting like a day and a half.  So the last 3 months the sun has been slowly and imperceptibly (on a daily basis) climbing higher and higher in the sky to reach a maximum of  23.4 degrees, consistent with the tilt of the earth. At 6:30 PM yesterday, the 22nd, (21’st in the US), the sun reached its peak.  While the rest of the day, was the most overcast day we have experienced so far, suddenly around dinner the sky opened up which I noticed at my desk drafting my next blog posts.  Having made a facebook post about probably not getting a solstice shadow shot, I had to put my coat on and go out to the ceremonial pole and take a few pictures.  It was a record high of 6 below zero at dinner time so I went in my jeans, bunny boots, neck gater, and big red coat and medium gloves, and of course the goggles to not be blinded.  As I stepped outside the air did not even feel cold, though my face was telling me otherwise by the time I returned. (Fun trying to take photos with an LCD screen and those fly-eye looking dark goggles.) 

So the pole marker was 4’ 8”  (56”) shadow was almost 12’; 130 ½ inches.  You do the math.  Just kidding.  Damn, now I have to do the math.  ArcTan(56/130.5) converted to degrees is 23.25 very close to the expected value of 23.4.  So despite suspicions of late, the Earth is not off its axis of rotation after all..  As you can see from the picture, it is a bit tough to tell exactly how long the shadow is.  So good enough for Raytheon work.  Unfortunately, the geographic pole was casting its shadow onto the sign at the time so it wasn't an option for this shot.  With some new weather blowing in, a mechanical delay on today's flight (first since Tuesday) it is unlikely that I will get out and see if I can get a more accurate measurement at the geographic pole marker.  Meanwhile, if today's flight does not go on several McMurdo people are stuck here for a fabulous Christmas dinner and until Monday for the next possible flight.  Thankfully, my sister's Christmas package arrived on Tuesday's flight so I have some gifts to open.  Thank you, Kathy.  More Photos, click here

No comments:

Post a Comment