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Name: Owen
Status: other
Grade: other
Country: Australia
Date: Spring 2012


Question:
I have checked the archive and it is not really answered there. http://www.newton.dep.anl.gov/askasci/gen01/gen01052.htm isthe closest link but does not really get to the crux of what I amasking below. Is the solstice still the longest day (in either hemisphere) if your location is between the Tropics? Some friends and I have been debating this. One faction argues that the solstice on 21 December is the longest day here in Cairns, QLD, Australia. the other faction claims that the longest days here are when the sun is directly overhead (we believe the days to be 28 November and 12 January here in Cairns) and that the days shorten between 28 November (zenith in CNS) and 21 December (solstice) ... then graduate/lengthen back to the maximum between 22 December until 12 January (our other zenith day as the sun moves back North) ... after which, they shorten again. can you please settle the debate (with an explanation).



Replies:
Owen,

Your summer solstice (in whatever hemisphere you are in) is the day with the longest daylight period, no matter what latitude you are at. The day that the Sun is at zenith at your location is not the longest daylight day. You can see this by looking at the table of sunrise and sunset times for Cairns at

http://www.timeanddate.com/worldclock/astronomy.html?n=927&month=12&year=2012&obj=sun&afl=-11&day=1

David R. Cook Meteorologist Climate Research Section Environmental Science Division Argonne National Laboratory



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