The article talks about what winter is, how it happens, depending on the place on the planet, and why the seasons change.
Seasons
Life on our planet exists, according to some estimates of scientists, for more than 3 billion years, and in our entire solar system, only the Earth is lucky to have certain conditions for the development and maintenance of biological life. There are many such factors. This is the presence of liquid water, a certain distance from the central star, gravity, atmosphere, etc. But there is another factor, this is the rotation of the planet around its axis, due to which the seasons change. How are they related? Very simply, consider the example of the same Mercury. This planet is too close to the Sun, and, moreover, always faces it on one side, which is why the temperature on the sunny side reaches almost 500 degrees Celsius, and eternal darkness and cosmic cold reign on the night. So, as you can see, the seasons are very important. And in this case, we're talking about winter. So what is winter?
Definition
First of all, let's understand the terms. Winter is the coldest time of the year, when the temperature stays steadily below zero degrees Celsius and snow often falls. If atake a calendar winter, then in the northern hemisphere it lasts 3 months - December, January and February. And in the south - July, June and August. So now we know what winter is. But why does it occur?
Axis Tilt
It's all about celestial mechanics, how the planet rotates. With a certain periodicity, the Earth changes the tilt of the axis of rotation with respect to the plane of the ecliptic, therefore, the northern hemisphere receives less solar heat, due to which the average daily temperature gradually drops, and at the moment of its stability below 0 degrees, and the actual winter time comes. This is called astronomical winter, in the northern hemisphere it lasts from December 22 to March 21. So we sorted out the question of what winter is.
Weather conditions
Despite the dates of the astronomical and calendar winter, the cold season with negative temperatures and precipitation everywhere comes in different ways. For example, in the Russian village of Oymyakon, starting from August 31, thermometers often show negative temperatures, the same applies to other regions of Yakutia and Chukotka. Well, in Primorye and the Khabarovsk Territory, due to their proximity to the ocean, the climate is milder, and the cold comes, respectively, later.
Dealing with the question of what winter means, it is worth mentioning ocean currents, which play a big role in climate. For example, Holland, which is washed by the Gulf Stream, has a mild and temperate climate, while the same Chukotka, being almost at the same latitude with it, suffers most of the year from the strongestfrost and precipitation.
Eternal Summer
There are areas on Earth where there is never winter. And what the locals take for cold will only bring a smile to the inhabitants of the northern hemisphere, and this is the equator. Again, due to the tilt of the earth's axis, there is almost no change of seasons there, but rainy seasons do occur regularly.
Polar night and day
Both the north and south poles have two very interesting phenomena, polar night and day. The polar night is the period when there is no sun for more than a day, the same with the day, only the other way around - when the sun does not set all 24 hours. The duration of these phenomena is highly dependent on the time of year and longitude, but the longest period of the polar night regularly lasts almost half a year.
Despite the fact that people live for a long time with such phenomena, they still affect a person both psychologically and physically. During the night, people often experience depression and severe vitamin D deficiency.
Thus, we figured out what winter is, the definition of this word is also considered by us.
