Ilm-fan muammolari yosh tadqiqotchilar talqinida

“Ilm-fan muammolari yosh tadqiqotchilar talqinida” 
mavzusidagi 9-sonli respublika ilmiy konferensiyasi
 
5 
Looking at the daily change in air temperature, it also changes as the Earth’s 
surface warms up. The air warms up and cools down on Earth. The amplitude of daily 
temperature changes in the Metrological cabin is on average one third less than on the 
soil surface. The rise in air temperature begins in the morning after sunrise, 
accompanied by an increase in soil temperature (after 15 minutes). At 13-14 hours, 
the soil temperature reaches its maximum and begins to decrease. At 14-15 hours, it 
will be equal to the air temperature, since then, with a further decrease in soil 
temperature, the air temperature will also begin to decrease. Thus, in the Daily course 
of air temperature, the minimum temperature corresponds to a time when the sun 
does not pass much, and the maximum temperature is 14-15 hours, but such a daily 
change occurs only in stable weather, any change in meteorological conditions 
(radiation, cloudiness, the introduction of air masses, etc.) leads to its change. The 
average daily temperature amplitude depends on the following factors: 
- latitudes of the region-at latitudes 20-30° on land, the average daily amplitude 
throughout the Year is about 12°C; 60° - about 6°C, 70° - only 3°C. At the highest 
latitudes, when the polar night begins, there is no regular change in daily temperature 
at all. In general, with an increase in latitude, the daily air temperature decreases, 
since the height of the sun above the horizon at noon decreases. The nature of the soil 
layer, the effect of the soil layer on the daily air amplitude, is directly proportional, 
the greater the amplitude of the soil temperature, the greater the amplitude of the air 
temperature. In steppes and deserts, the mean daily amplitude reaches 15-20°C, 
sometimes 30°C. Above the continuous vegetation cover,it is much less. [1]. 
Modern constructions of non-Capricorn roads must be fixed within a certain 
temperature range in accordance with the climate of the area. On rail plets, we will 
have to distribute the tension in the following cases, and it will be performed as a 
separate work: 
- when the rail plinth is fixed, the temperature is more than 5°C higher or lower 
than the optimal temperature; 
- if the difference in fastening temperature when welding adjacent plets 
exceeds 5 °C and exceeds -10 °C at the time of welding all plets; 

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