At what rate does the length of the days change after the winter solstice?

Question

So December 21, the winter solstice, is the shortest day of the year for the Northern Hemisphere. That makes the winter solstice a day that encourages optimism because after it, the days only get longer. But how many seconds or minutes do they increase each day? I am sure this depends on what latitude the length is measured from. My guess is that the days increase more slowly at first because of the earth's elliptical orbit, but I am not sure. Is there a chart or equation with which to measure?

Answer 1

Yes, the length of the day does depend on latitude,
but the graph showing length of days is quite stable
over the whole year, for any particular location.

I don't have any equations to give you, as they can be
quite involved, but I do have another way out.

1) Go to this fabulous website :

http://www.analemma.com/Pages/framesPage.html

2) Click on the yellow title "other phenomena".

3) Scroll down near to the end of the page and click
the SunGraph image. You will then be offered a
choice as to which one to download.

4) You can enter your own location and see the yearly
graph. You should be able to estimate within, say, 5 -10
minutes, the number of hours of daylight on each day,
and be able to see how much one day differs from the next.
You have to admit, this is a beautiful program.

This graph will be the same for all years, so it's possible
for your particular location, to note down, say, 12 points
for the months (you may need more) and the
corresponding day length, and create your own local
equation, as I have done many years ago. Depending on
the curvature, you may find that putting your points into
either a 2nd, 3rd, 4th or 5th degree polynomial may be
sufficient for your needs. You just have to see which is
the best fit for your points.
Alternatively, forget the equation and just print out the
page using ALT/PRINT SCREEN and paste into Paint.

Hope you have fun with this.

Answer 2

This Site Might Help You.

RE:
At what rate does the length of the days change after the winter solstice?
So December 21, the winter solstice, is the shortest day of the year for the Northern Hemisphere. That makes the winter solstice a day that encourages optimism because after it, the days only get longer. But how many seconds or minutes do they increase each day? I am sure this depends on what...

Answer 3

The orbit is not very elliptical, so this makes little difference. But it does indeed depend on you latitude.

The easiest way to estimate it is to think about it this way. The change in day length from shortest to longest takes 6 months everywhere on Earth, and is sinusoidal in nature. Near the solstice the change is almost zero - you are at an extremity of the sine wave. The change per day is roughly:

z.sin(pi.d/182)

where d is the number of days since the solstice and z is the difference between the shortest and longest day at your latitude. If you plug number into a calculator from this remember to set it to radians.

Answer 4

the change in day length, between winter and summer solstice, depends on the latitude of a specific locations, places near the equator change negligibly, while places near the poles change to an 24 hours day/night.
the rate of change is maximal at midterm between the 2 solstices.

Answer 5

This should help you. You can look at a whole year at a glance.

Generally, around the equinoxes in March and September, the days are getting longer/shorter at their fastest rate. During the solstice, the minute per day change is nil... Here's the link:

http://aa.usno.navy.mil/data/docs/RS_OneYear.html

Answer 6

Day Length Graph

Answer 7

It seems as though the days get longer at sunset faster than at dawn. is this true?

Answer 8

I don't know