Archive for the ‘ miscellaneous ’ Category

atlbike Weather page

It is interesting to see the weather patterns for the CONUS (Continental US) and how these patterns are driven by troughs in the jet stream.  Looking at the video screen shot with the time lapse satellite infra-red image (center) you can see the jet stream driving cold polar air into the south. [click the video below]
Current atlbike weather page.

embedded by Embedded Video

YouTube Direkt

Note: click image below for a larger detailed view

Weather Maps: Composite (current), Time Lapse Infra-Red, 300mb jet stream.

Weather Maps

Weather Maps

sunrise, sunset times: not what you might think.

Many people are aware of the winter solstice which is the shortest day of the year, which last occurred on December 22nd. However this date is not the latest sunrise nor earliest sunset for the year. Keeping this discussion practical, rather than technical, let’s ask the question, “So what does this mean to me as a cyclist?”

A good web based tool to look at for data like this.

Wikipedia has an excellent semi-technical description.

AxialTiltObliquity

AxialTiltObliquity

Using the data from the time-and-date site I found that the earliest sunsets actually occur in early December and the latest sunrises occur in early January. So, here we are in mid-January, how does this effect our cycling or other outdoor activities?

Data for Atlanta, Ga:
Jan 16, 2011
Sunrise: 7:42 AM Sunset: 5:53 PM
Daylight hours: 10h 10m 37s
Daylight hour change: + 1m 10s

Since the Winter Solstice occurred, our daylight hours have increased 16 minutes, but sunset times are actually 24 minutes later from early December. On the other hand, sunrise times are only 3 minutes earlier since the solstice.

Another thing to keep in mind is that the rate of change for these processes is highest near the equinoxes (equal day/night hours). During mid-March the days are getting longer at a rate of 126sec/day. During early October the days are getting shorter at a rate of 124sec/day.

So if it seemed to you, that the celestial events like sunrise and sunset weren’t in sync with the solstices, it wasn’t your imagination.

Sunset on the Trail: Florence Rd

Forrest and I had returned to Florence Rd a bit late.  Forrest ran off to check his Ebay bid for some geeky uwave power meter.   I stayed to enjoy and photograph the Sunset.  The scale of the image is fairly large as the final result was three images, digitally stitched.

Click the image to enlarge.

Sunset-SCT-Florence

Sunset-SCT-Florence

WG@frankie’s.tunnel

WG at the Tunnel

Frankie had a cute idea. With all the work we’ve been doing at the tunnel, what better than a photo of me at the tunnel.

(click image to enlarge.)

Coots Lake Mirror

Coots Lake Mirror

We rode from Coot’s Lake this morning. While getting ready to ride, I happened to notice the mirror like calmness on the lake. Pulled out the camera and shot this photo.

(Click image to enlarge).