We suggest that you understand how long daylight hours will be in different regions of Russia (Moscow, St. Petersburg, as well as beyond the Arctic Circle) in January 2020 and why this parameter can differ significantly for the central, southern and northern regions.
Longitude of the day - this is the time interval between the moment of sunrise and sunset, during which the luminary is above the horizon and illuminates the surface of the Earth.
Geographical location and daylight hours
The following factors influence the length of daylight hours for a certain point on the Earth:
- geographic location (northern hemisphere, southern hemisphere, equator);
- angle of solar declination (has seasonal changes).
Interesting fact! At the equator, the longitude in January, July, and other months of 2020 will be approximately the same - about 12 hours, but as you approach the poles of the Earth, this parameter will deviate more and more from the equatorial indicator.
For the Northern Hemisphere, in which Russia is located, the longitude of the day decreases in the winter and increases in the summer. Scientists distinguish four main dates in 2020:
Day of spring equinox
Daylight hours about 12 hours
The longest day
Daylight hours about 12 hours
Interesting fact! In the southern hemisphere, everything happens diametrically - the shortest day of the year falls in June and the longest in December.
Moreover, in latitudes closer to the equator, the change in daylight hours is less noticeable than in the north, and for the regions of the Far North there is the concept of a polar day (when the longitude of the day approaches 24 hours) and polar night (when this parameter is close to 0 )
According to the scientific longitude of the day for a certain point on the globe, you can calculate using the formula:
So, let's see how long daylight hours will be in individual regions of Russia and how this parameter changes with changing latitude.
Longitude of the day in Moscow
Since the winter solstice falls on the second half of December, the daylight hours in the first month of the year are still very short, but it is gradually increasing. The average longitude of the day for the capital in the first days of January 2020 will be about 7 hours 10 minutes, and by the last days of the month daylight hours in Moscow will increase to 8 hours 30 minutes. Accordingly, the duration of the dark time of the day is reduced from 15 hours 20 minutes at the beginning of the month to 14 hours 10 minutes by 01/31/20.
Given the data obtained by scientists, it can be predicted that such a schedule will be relevant for the capital:
For the 31st day of January, the height of the solar disk above the horizon also changes from 11.72 ° on 01/01/20 to 17.04 ° on 01/31/20.
January is one of the coldest months for the capital, because during this period the sun rarely shows because of clouds, and at night the temperature can reach extremely low values. Such climatic indicators are directly related to the deficit of sunlight and are the norm for all settlements located like Moscow, at 55 ° 45 'north latitude.
Longitude of the day in St. Petersburg
St. Petersburg is located at 59 ° 57 'north latitude, which determines certain features of daylight in this region.
Interesting fact! Despite the fact that the "White Nights" are the hallmark of the Northern Capital, in fact, there is no polar day or polar night in the region.
In June, the sun hides behind the horizon, but only for a few hours, and in the winter months it shows over the horizon, although the duration of daylight hours is really quite short. On the day of the winter solstice, it is 5 hours 50 minutes. By the beginning of the new calendar year, the day will have time to lengthen slightly, but it will still be only 6 hours 2 minutes for 01/01/20 and 7 hours 50 minutes on the last day of the month.
As you can see, the difference is quite significant when compared with the performance of Moscow or more of the southern regions of the Russian Federation. Also for Peter will be relevant such a schedule for changing light and dark:
Longitude of the day in Murmansk
As in many other settlements of the North-West, polar nights are observed in Murmansk. The sun will completely hide behind the horizon in December 2019 for 40 days and will again appear in the sky (very briefly) only on January 10, 2020.
But, unlike in the more southern regions, the daily increase in daylight hours will be more noticeable here, and if on January 11 the Sun appears for only 6 minutes, then on January 31 the longitude of the day will be 5 hours 11 minutes.
For Murmansk in January 2020, scientists compiled a table of sunrises and sunsets:
It is worth noting that the polar night end dates for different cities of the North of Russia are different. So, the Sun will return to Naryan-Mar already 02.01.20, and to Norilsk only on January 13.