Dawn

There was a couple of fantastic mornings this week, one before a storm and one after.  Both days I was out driving for work, but it was only the first that i was properly aligned to take a photograph of the sunrise.

Let me set the stage for these two mornings.  The air was filled with humidity.  I could feel the moisture in the air as I rode my bicycle through the pre-dawn air.  It was heavy in the air and it pressed on me as I rode.

There was no wind.  The air was still as I crossed the bridge.  No wind; the sounds of the birds were muted due to the lateness of the year but were heard clearly.  The sounds of my wheel echoed in my ears after rebounding off the edges of the roadway.  The sounds of distant cars was heard.  

It was warm.  Around five degrees when I started, but for early December, that is nearly hot.  with the moisture laden air you could say muggy December weather.  The ride was quite pleasant.  As I travelled North and further inland, the temperature steadily dropped.  The drop was more than just the distance inland, but the steady bleeding of heat into the clear air.  The temperature dropped to close to zero.  

Air stratified, the cooler heavier air close to the ground and the lighter warmer air on top.  because there was not wind, the layers did not mix and because the air was heavy with moisture*, the cooler air was at the dewpoint temperature for the air and the air became mist.  A thick heavy mist.  If the mist stirred and rose off the ground (because the ground was warmer than the air), its tendrils rose and disappeared slowly as they rose.  In the early light the mist radiated the light, it reflected it back in a bluish white to my eyes.  The trees and the fence posts sucked in the light, wetted by the mist, decreasing their albedo, they appeared quite black silhouetted amongst the white.  

The jet contrails stood out visible in the light of the new sky.  they did not dissipate like normal.  The moisture in the air at the surface was in the higher latitudes too, the slight southerly breeze in the higher air was moving the air mass as a whole, so there was little if any turbulence, so the contrails were very slowly diffusing and since the air was saturated they stayed present.  The cris-cross pattern, evidence that multiple plane passages had occurred and the stability of the air mass preserved them.  The light of the sun reached them first, but only the red light that bent around the Earth from the position of the Sun as the Earth turned; they glowed pink.  

As my work day started, I was on the road and the Sun had been threatening to peak for over an hour but had finally decide that it was time.  Because the Earth has a tilt to its axis it has seasons, but it also affects the dawn and twilight periods.  The day does not really change ever, it is twenty-four hours long.  Closer to the poles the Sun tracks closer to the horizon during that day and night than it does in the summer or in the tropics.  This means that it also takes longer to rise above the horizon too and longer to set, like a diver who plunges deeply into a pool versus a shallow dive.  

The Sun when it does cross the horizon, bulges and elongates as the light piles through the Earth’s gravitational field.  

It appears relatively larger too because we see it relative to things we see and understand as opposed to in the sky against the backdrop of nothing we know.  

iPhones have a crappy zoom feature