Change of Seasons
The well known division of a year consists of summer when the daylight period is the mostly long-continued and the sun raises high on horizon; winter with the famous shortness of day time and long nocturne hours; two demi-saisons such as spring and summer which serve to be kind of a pass between the main annual stages.
Vivid imagination in full measure the picture of these metamorphoses, it is well worth to describe how the terrestrial globe moves in the space.
There are two space rules which are capable to do it.
1) The Earth complete own space-voyage around its axis (imaginary line through a celestial body, that divides on two poles) is realized in a term of 24 hours. Due to this astronomic event people observes the day and night changes. When in the continents directed to the Sun is a burning midday, the opposite hemisphere sinks in deep night.
2) Our globe goes forward on the elliptical orbit around Helios, realizing the whole turn during a year.
What forces the year do not look the same?
Terra orbit has a form of ellipsis and the extremums are exemplified as two points: perihelion (the nearest to the Sun, 147 millions kilometres) and aphelion (the mostly distanced point from the Sun, which counts 152 millions kilometres). Just 3% difference in the destination leads to the 7% amount variation in sunlight received by the perihelion and aphelion points. The delusion exists that when the Earth is closer to the Sun is getting warmer and vice versa. It is totally wrong conclusion! Oppositely the perihelion in January falls on the Northern hemisphere when it is the season to prepare for skating and sledging.
It is curious to know that the Earth position according to the Sun does not imply the wheel of changes of the annual season. The key role plays the angle of the axial inclination, which in the case of the planet is 23,5°. During the annually rotation around the Sun our globe could be faced to the Northern or the Southern hemisphere. Summer is on the threshold of the hemisphere (which is turned to the centre of the Solar system) because it receives trice more the solar energy and the warmth. Logically, winter rules on the opposite hemisphere that is directed far from the Sun and does not receive so much the Sun energy and hours.
If the terrestrial powerfulness of the axial angle inclination could not exist, the planet would turns around the Sun in the vertical position, so the seasons would not have a place. In this case each point of the globe on the lighten surface would be on the same lengths from the Sun, owing to the air would be warm too.
How does it to pass a year in the Northern hemisphere area?
During the time when the terrestrial globe rotational axis leads the Northern hemisphere, Helios getting closer and summer achieves above mentioned part of the world. The daylight luminosity increases and in the places which are near to the pole is even credibly luck to observe the light time at midnight.
Other stage forced by the rotational axis makes the Globe to be by the opposite side according to the Sun, so the angle of blue planet axial inclination removes the Boreal hemisphere from the solar rays and winter comes here.
The hours of darkness increase the longitude and the daylight is getting shorter. The Southern hemisphere continents celebrate the hottest season at the same time.
It is rewarding to know that the populations who live in Equatorial and Tropic zones know about the coldness by hearsay. The season changes are so slowly gradual that are near unnoticeable because the Equator does not depend from where would be the planet on the orbit and always is far from the Luminary equally.
Dual-cycle of equinox
The spring equinox is indicated as one of spring feast falls on March 20 – 21. The Sun comes from the Southern hemisphere to the opposite one.
The autumn equinox is on September 22 – 23 when Helios realizes its hemispherical came back.
Not only astronomic researches demonstrate that it is the reason of contradiction between the hemispheres. The period between demi-saisons during which the daylight the most of time the N-hemisphere looks on the Sun, so it receives warmer and sunlight than the S-hemisphere. The period is characterized by prolongation of days and shortening of nights.
After 6 months the Earth changes it preferences due to the Sun position but the axial inclination is left. So, the summer time comes in the Southern latitudes of the hemisphere. In the Northern hemisphere is winter. This cycle of transformations during a year is sufficient for making colder or warmer the certain parts of the planet. In correspondence of it the season changes gradually and divides the year for four parts.
The Earth is represent own peculiarity in the view of some climatic zones which are characterized by the certain climate. This fact is linked with the peculiar physical properties of the surface and the waters in the different corners of the globe. It is the crucial point why on the different continents the season begins not in the same manner according to the astronomic phases.
It happens that on the one continent snow falling could be in winter and raining in summer but on the other it could be absent during a considerable period of time, however, the season of rains would be rigid fixes to the certain season.
Archetypical climatic zones on the Earth
Equatorial zone is distinguished by the seasons of dryness in spring and autumn and constantly rainy weather in winter and summer.
Tropical zone is depicted as the zone of dry and hot weather during near a whole 365 days and only once the season of rains shows the heavy precipitation and coldness.
Temperate zone (West Europe, part of Russia) is famous with it dry spring and summer with a few precipitations; frequently rainy autumn and stable snowy winter.
In Arctic (the same for Antarctic) the seasons changes only in the aspect of the gradual shift of the polar day and night. The weather changes are rather unnoticeable and the temperature is constantly below the zero.
The seasonal changes had been seen by Norwegian photographer Eirik Solheim, who combined the shoots inspired from the same place during 40 seconds.
The outstanding video dedicated to the changes of the seasons. All the seasonal changes of the weather during a year are shown exactly in the period of 40 seconds. The author made a photo hear each day during an annual period and the result of it is the integration into original experiment in the short video format which clear demonstrates the weather peculiarities.
Drawing conclusion, it is worth to underline again that the summer season begins when the hemisphere where we are habitants is faced to the Sun, so it provokes the raising the temperature up and when in our hemisphere the Sun shines less is winter. It is not mythological influenced by the space between the Earth and the Sun but connects with the Earth angle of axial inclination which is 23,5°.