Air temperature ... and the difference between it and the palpable temperature

Weather of Arabia - The air temperature that a person feels sometimes may differ from the temperature that is announced in the weather bulletins, where a person's feeling of cold or heat depends on several factors, so what are those factors? Why does the perceived temperature (perceived by a person) sometimes differ from the recorded temperature?

What is temperature and how is it measured?

Temperature is a measure of the amount of thermal energy carried by an object or system, where temperature is an indication of how cold or hot the objects are.

The temperature is measured using a thermometer , which can give the temperature in several systems, including degrees Celsius (° C ) and Fahrenheit ( °F ).

Factors on which air temperature depends

Temperature is one of the important elements in determining the weather and climate on Earth, so meteorologists are interested in measuring the air temperature periodically, as the air temperature expresses how hot the air is, and the air temperature in a particular area depends on several factors, one of the most important of these factors :

• The amount of solar radiation that reaches the Earth, which is the main source of heating the Earth's surface and air.
• The topography of the region and its height above sea level, where the air temperature drops, for example, in mountainous areas due to its distance from the surface of the earth, and the difference in air pressure in it.
• The distribution of water and land in and around the region. There is a discrepancy in the absorption of the sun's heat between water and land, which affects the heat transmitted to the air in contact with it.
• The movement of winds and air masses, such as cold air masses lowering the air temperature in the area they reach.

Measuring air temperature

When the air temperature is measured in a certain area, external factors that affect the accuracy of the readings are excluded, so the temperature of the still air is measured at a height of 2 m above the ground, using a thermometer placed in a box through which the air passes, and thus is not affected Measurement by wind, sunlight, or surface temperature, while we find that the temperature recorded in an open space, such as mobile and open air gauges, is a few degrees lower than the recorded temperature, depending on the wind speed.

But why does the temperature that a person feels sometimes differ from the recorded temperature?

There is a certain mechanism in the human skin to deal with the temperature of the atmosphere and the conditions associated with it, such as the process of sweating , in order to maintain the stability of the human body temperature. It is announced in weather bulletins, where a person's feeling of cold or heat depends on several factors related to the process of sweating and the evaporation of sweat from the skin, including:

• amount of sunlight.
• Humidity in the air, where the high humidity reduces the evaporation of sweat on the human skin, increasing its sense of heat.
• Wind speed, which increases a person’s feeling of cold due to its role in increasing the evaporation of sweat or moisture from the skin. If the air temperature is zero degrees Celsius, and the wind speed is 10 km/hour, the temperature that a person feels is about three degrees lower than zero Celsius.