Thursday, June 16, 2016

Daylight-Twilight-Astronomical Maps

Here is my collection of maps showing length of daylight and twilight. They are in no particular order.

























Hours of daylight on the winter solstice.






Difference between the hours of daylight on the summer solstice and the winter solstice.


Difference between the hours of daylight on the summer solstice and the winter solstice (Alaska focus).

Summer solstice sunset (local time).

Date of earliest sunrise and latest sunset in summer.


Date of earliest sunset and latest sunrise in winter 2015-2016.


Date of latest sunrise and earliest sunset by latitude.


Hours of daylight on the summer solstice.


Hours of daylight plus civil twilight on the summer solstice.


Average length of daylight plus civil twilight for all days of the year.


Average length of daylight plus civil twilight for all days of the year. Same as Fig. 6 but a N. America perspective and slightly different map categories.


Average length of daylight plus civil twilight for all days of the year. Same as Fig. 6 and Fig 7 but an Alaska-centered perspective.


Average length of daylight for all days of the year.


Average annual hours of 1) daylight and 2) daylight plus civil twilight by latitude in the northern hemisphere.


Number of days per year wit 24 hours of daylight.


Number of days per year wit 24 hours of daylight plus civil twilight.


Hours of daylight on the summer solstice. Northern Hemisphere perspective.

7 comments:

  1. Very interesting data. This is quite science, congrats for gathering all this information in one piece!

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  2. Earth has 36 hours 18 longitude lines on each side of Greenwich Mean Time from International Date Line just look at what I'm talking about

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  3. Looking at Figures 9-10, I guess it's safe to conclude that places in the world farther from the equator (i.e. Seattle) get more overall annual daylight that places closer to the equator (i.e. Honolulu). Enlightening!!!

    Despite more overall annual daylight in places farther from the equator, wouldn't trade consistency in the number of daylight hours in Honolulu (between 12-13.5 hours depending on the time of year) for a wider range of daylight hours in Seattle (between 8-17 hours depending on the time of year), not to mention the changes in weather!!!

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    1. There is something to be said for consistency. There's also something to be said for variety. :)

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