Seasons

What relationship between earth and the sun causes the seasons?

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2018-01-20 12:16:56

The Earth is tilted on its axis. 'Summer' (the warmest season)

occurs when a hemisphere, either the northern hemisphere or the

southern hemisphere, is tilted towards the Sun and thus receives

more direct sunlight (the Sun is closer to the zenith and is above

the horizon longer).

A common misconception is that the seasons have to do with the

Earth being closer to the Sun due to the elliptical nature of its

orbit. The orbit is elliptical and the Earth is closest to

the Sun [aphelion] in early January, farthest away [perihelion] in

early July. This has a minor effect on the seasons, but more

important is the number of days and weeks the Sun is higher in the

sky; near perihelion for the northern hemisphere (although the Sun

is further away) the atmosphere has the opportunity to heat up

more.

Twice during the year (spring and fall Equinox - around the 20th

of March and September respectively), the Sun appears to circle

more directly over the equator [the axis of the Earth is in a plane

perpendicular to the orbit], and most areas of the globe receive

similar amounts of daylight. The poles are exceptions, with

extremely long periods of the Sun either above or below the

horizon.

From late December to late March, the Southern Hemisphere

experiences 'summer' while the Northern Hemisphere experiences

'winter'. From late June to late September, the position is the

other extreme, and it is summer in the Northern Hemisphere, winter

in the Southern.

These yearly changes in insolation (incoming energy from the

Sun) cause the seasons, in conjunction with the prevailing

directional wind patterns, ocean areas, currents, and pressure

systems which all affect the local climate.

The tilt of the Earth in combination to its position during its

orbit around the Sun.

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2015-02-27 06:17:18

The reason for the northern hemisphere summer/ southern

hemisphere winter is that at the time of the June solstice the sun

is directly over the Tropic of Cancer. The reason for the northern

hemisphere winter/ southern hemisphere summer is that at the time

of the December solstice the sun is directly over the Tropic of

Capricorn. The reason for spring and fall is that at the times of

the March and September equinoxes the sun is directly over the

equator.

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Wiki User
2015-02-26 16:01:24

Seasons are caused by the tilt of Earth's axis, which is 23.5

degrees (with respect to the perpendicular to the plane of Earth's

orbit). This results in parts of the Earth getting more sunlight at

some times of the year, and less sunlight at others.


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