Temperatures: Factors That Influence Atmospheric Temperatures, Essay Example

It is difficult to overestimate the role of climate for the nature and human activity. It determines proportions of the heat and the moisture and, consequently, conditions of landscape, pieces of water development and plants setting. Climate also influences spacing of animal human populations.

The climate of any area is driven by a number of climate-forming factors. The two main climate-forming aspects are radiation and air circulation.

Radiation Conditions

The Sun is the only source of heat and light for our planet. The Moon and the stars give an insignificant amount of radiation. The radiative energy of the Sun heats the Earth’s surface which heats the lower atmosphere layers. Sun rays heat them much less.  The radiation that reaches the Earth without being absorbed or diffused is called direct solar radiation.

The atmospheric air contains tiny particles of liquid and solid substances such as water drops, dust, crystals. 10-100 % of sun rays strike this particles and diffuse in the atmosphere (National Renewable Energy Laboratory 12). This part of solar radiation is called diffused radiation.

All the Sun’s energy that reaches the planet is called global solar radiation. Its amount depends on its incident angle, day length, sky cover and air transparency. That is why in big cities, where the air is polluted, the temperature may be higher than in rural areas.

Air Circulation

Air circulation influences the climate in general and the temperature not less than solar radiation.

As a result of different physical characteristics of the land and the sea, the air that touches them heats differently. Consequently, there is a transition of air masses of various origin – the atmospheric or air circulation. Thus local winds have an impact on the temperature too.

Albedo

A factor that is closely connected with the solar radiation and local temperatures is albedo.

Dagmar Budikova states that “albedo is known as surface reflectivity of sun’s radiation. The term has its origins from a Latin word albus, meaning “white”. It is quantified as the proportion, or percentage of solar radiation of all wavelengths reflected by a body or surface to the amount incident upon it.” (Budicova et al, n. p.)

Different materials have different albedo: fresh snow albedo varies from 40 % to 95 %; green grass has 21 % albedo. On the other hand, it is 4 % for fresh asphalt and 12 % for worn asphalt – even less than for bare soil (up to 5-40 %) (Budicova et al, n. p.). As a result, in urban area, where there is less grass, trees and other vegetation but more dark surfaces (such as pavements and concrete walls), the air temperature may be 6-8 ?F higher than in the surroundings (Heat Island Group, n. p.) Such areas are called “Urban Heat Islands”

The temperature rise leads to an increase in energy demand needed for air conditioning and this, conversely, causes air pollution and again a temperature rise.

All the above mentioned (solar radiation, air circulation, albedo) explains the temperature difference between urban and rural areas and why certain settings tend to be warmer on a given day.

Works Cited

Budicova et al. “Albedo”. The Encyclopedia of Earth. The Encyclopedia of   Earth, May 8 2010. Web. May 8 2010.

National Renewable Energy Laboratory, ed. Shining On: A Primer on Solar Radiation Data. Golden, CO: Solar Radiation Assessment Project, Development and Communications Office, May 1992: 12. Print.

Pon, Brian. “High Temperatures”. Heat Island Group. Heat Island Group, d. Web. Apr. 27. 2000.