Sunrise

I usually arrive at work at 7:00 am, and while I have noticed the morning is coming earlier the last few weeks, the early arrival of sunrise will be offset by the movement to Daylight Savings Time (DST) in less than a month.  According to charts from the US Naval Observatory, today, February 12, 2014 marks the first time since November that the sun will arise at or before 7 am.  As my luck would have it, it was a cloudy morning boding of snow, mitigating the affect, to me anyway, of a critical juncture in the movement to spring. Latitude wise, Madison is slightly north of Milwaukee, but because Milwaukee is further east it saw a 7:00 am sunrise five days earlier.  I should be glad that I am not in the vicinity of St Joseph, MN, or central MN, where the sunrise today will be at 7:24 am.  St Joseph's will not see a sunrise on or before 7 am until February 27.  St Joseph's latitude would place it about 171 miles north of Madison, but they are almost 5 degrees (d) further west than Madison.  Because longitude has varying distances apart as they move toward a convergence at the poles of the earth, I will leave it to mathematically minded individuals to calculate its distance west of Madison, at least in terms of longitude.  New Orleans, by contrast, at least based on standard time, will not see a sun rise later than 6:56 am this year.  Of course, because of the upcoming correction to DST, residents of that city will see days where the sunrise will be after 7 am.

Google images

If March 9, the start of  DST, were still according to standard time, the sunrise on that day would have been 6:20 am for Madison, a rather remarkable almost forty minute increase in less than four weeks.  But, with the hour change, DST will push back sunrise to 7:20 am on that day.  New Orleans, by contrast, will see a sunrise on that date of 7:17 am, only a few minutes ahead of Madison, but due to its lower latitude it will take until March 24 before the sun will (according to DST) before 7 am.  New Orleans, is at N29d 58' latitude, compared to Madison's N43d 05'.  Each degree latitude is about 69 miles in distance.  Unlike longitude, latitude is constant.

On the day of the summer solstice, with DST, Madison will see a 5:18 sunrise, while New Orleans will see one at 6:00 am.  Of course, if you want length of day, you need to take sunset into account.  On June 21, Madison will see a sunset of 8:41 pm, New Orleans at 7:50 pm, and St Joseph, MN at a nice long 9:10 pm.  Due to its location about 6 d north of the Tropic of Cancer, New Orleans has a more even length of day over the course of the year than we in the upper Midwest, particularly those living near St Joseph.  One notices that as Fireworks on the fourth of July begin at 9:15 pm here in Madison, but in Superior, WI they begin at 10:00 pm.  The Tropic of Cancer is set on maps at 23.5 d north, but in actuality, it marks the northern most level of the sun during the summer in the northern hemisphere.  This movement is variable, and this year the sun will be at 23 d 26' (and for the anal among us, add a suffix of 14.675").  As the summer and winter solstices denotes the start of the summer and winter seasons, the vernal (spring) and autumnal equinoxes are the start of spring and fall.

Stone Henge (source: Google images)

This year the spring equinox is March 20.  This then leads us to the furry rodent that Sun Prairie celebrates. If this groundhog sees it's shadow, than the prediction is for six more weeks of winter, if not it is an early spring.  As most technical observers will note, since groundhog's day falls within a day or so of the mid point of the calendar winter season, there is of course six more weeks of winter.  But what the calendar says and the way the weather actually is or feels are two different things.  What or how we feel the weather, is more important than what the calendar says it is to be.  In spring of 2010 we had 80 degree days in March, while last year we had a long, cold, and wet spring--almost to the point where we wondered if we actually had a spring.  The handlers of the fuzzy, hibernating rodent, claim a high success rate for the rodent's predictions, which begs the question of how one (or they) measure an early spring or a late winter.  Do we take a certain factor of allowed variation of the average daily highs for a week?   Perhaps the best portend we had for this winter was not the rodent, but the cold spring of last year. This winter we have had temperature lows, while not setting records, have not been seen for 20- 30 years.  Frost depths are reported in some areas to be seven feet deep, and many communities are asking water customers to run a pencil width of water all day long to avoid laterals from freezing.  Perhaps what this proves is that no one can predict the weather, not a rodent and some would say, certainly not a meteorologist.

Sun Prairie's Jimmy the Ground Hog (center), (source:groundhogcentral)

 Sunrise and sunset is an interplay of our geography, the position of place in relation to latitude and longitude.  The fact of nature is that the sun will rise in the east and set in the west.  According to natural low, the sun has a high point in the north near the Tropic of Cancer.  In the end, after a cold winter, and last year's nasty spring, most of us are hoping for a nice spring in 2014, regardless of when we see the sunrise.  It is nice, however, having day light, when I arrive to work.