All the parts of the Earth do not receive equal sunlight. Thus, temperature varies from region to region. Factors affecting the distribution of temperature on Earth are
Factors Affecting the Distribution of Temperature on Earth
Differential Heating and Cooling of Land and Water
As discussed above, land absorbs and releases heat quickly, while oceans and seas retain heat for a longer period of time. Oceans in the Equatorial Regions remain hot and give rise to warm currents.
On the contrary, oceans in the Polar Regions are cold. When warm currents move towards the cooler region, they transport heat to the polar latitudes.
Similarly, cold currents moving from the Polar Regions to the Equatorial Regions bring down the temperature of the coastal areas located in the Equatorial Regions.
For example, the warm North Atlantic Drift raises the temperature of Northwestern Europe. As a result, the port of Bergen in Norway does not freeze even during winters.
Because the Earth is spherical, the rays of the Sun strike the Earth at varying angles of incidence.
The areas lying in the Equatorial Regions receive direct or vertical rays of the Sun, so the temperatures are high.
As we move away from the Sun to the Polar Regions, the temperature decreases. The Polar Regions get slanting rays of the Sun; therefore, the temperature is extremely low. This is the reason that the Poles of the Earth are covered with snow.
Altitude means height. The air is dense near the surface of the Earth as it contains dust particles and water vapour. These particles absorb heat, and thus, the surroundings are warmer.
However, at high altitudes, the air becomes less dense and generally does not have dust particles, and therefore, less heat is absorbed.
Hence, in summer, people from the plains (where the temperature is 35ºC) visit hill stations (where the temperature is about 13–14ºC).
Distance from the Sea
The temperature of a place also depends on its distance from the sea. The land has the property of absorbing and releasing heat quickly, while the sea takes a relatively long time to absorb and release heat.
Therefore, the land gets heated during the daytime and becomes cooler at the night. On the contrary, the oceans are cooler during the daytime and are warmer at the night.
Thus, the coastal areas (Mumbai) experience cooler winds even in the afternoon, while the plains (Allahabad) experience extremely hot winds during afternoons.
The direction of Mountain Ranges
The direction of mountain ranges influences the temperature of a place. In the Northern Hemisphere, the Himalayan Mountains stretch from west to east. Thus, they act as a barrier to the cold winds blowing from the poles.
Therefore, the Gangetic Plain has a relatively moderate temperature and does not freeze. However, in North America, the mountain ranges stretch in the North-South direction. Therefore, they allow the cold polar winds to blow up to 30º N latitude, lowering the temperature of the region and resulting in snow formation. Therefore, New Orleans located at about 29ºN has snowfall in winter.
Soil and Vegetation Cover
The plant and forest cover helps in reducing the temperature of the place.
Various kinds of soil support various vegetation and plants. As the plant cover affects the amount of rainfall in a particular region, it also defines the climate of the regions.
A forest cover absorbs more sunlight than bare ground or snowfields. Most of the absorbed sunlight is used by plants and trees in photosynthesis. Thus, the forest cover reduces the temperature of a place.
Cloud Cover and Humidity
Heavy cloud cover prevents incoming solar radiation and keeps a check on the outgoing radiation. Thus, in the hot wet regions, where the cloud cover is dense, the average temperature usually does not go beyond 30°C.
There is no cloud cover in the desert regions. So, there is high insolation during the daytime and rapid loss of heat because of terrestrial radiation at night. As a result, deserts are hot during the daytime and cold during the night.
Also, Read Heat Zones of the Earth