El Sol en el Polo


Being at the point where the Earth rotation axis goes through has interesting consequences. One is to have the Sun up for 6 months and down for other 6 months. But other places above the polar circles also experience the midnight sun. Poles are special in one sense. Let’s see it with a formula, but don’t panic. The Elevation of the Sun as a function of location, day of year and hour of day is given approximately by:

sinA=cosh cos’d’ cos’L’ + sin’d’ sin’L’

Usually greek letters are used for angles, but I didn’t manage, ‘A’ is the Sun elevation angle, ‘h’ is related to the hour of day, ‘d’ is the Sun declination and depends on the day of the year, and ‘L’ is the latitude. The formula may look complicated, but at Poles it simplifies, because ‘L’=90 and cos’L’=0. Then we are left with the second term and we see that elevation depends only on declination, namely, on the day of the year, but not on the hour of day! This means that at Poles, the Sun is at the same elevation for the 24h of the day! It only goes up or down a little bit each day. Now it will go up until the solstice in December and then go down until the equinox at the end of March when it will roll along the horizon to sink and hide for 6 month! It is fascinating. One consequence is that I need to cover my window in order to sleep at ‘nignt’ :).
Without formulas, it is easy to understand that being at theEarth rotation axis the Sun spins around us as would do the furniture in your room if you spin.

COMMENTS (5)
Reply

APROVECHA ENTONCES ESTOS MESES,QUE LUEGO YA SABES QUE TIENES 6 MESES DE ABSOLUTA OBSCURIDAD,O SERÁ PENUMBRA? .EN CUALQUIER CASO ,¿PODRÁS HACER EXPEDICIONES NO?.SEE YOU

    Reply

    hola, oscuridad total no son 6 meses, pero si que llega a tres o cuatro. Pero dicen que en realidad es el mejor periodo, por las auroras. ya veremos.
    ciao!

      que gozada

        🙂

Reply

Hola, acabo de descubrir tu blog y me ha dejado fascinada, suerte en tu periblo que seguiremos de cerca 🙂

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