5. Factors affecting Climate/Weather

Moving away from the equator towards the North or South poles will show a gradual decrease in the region's atmospheric temperature, i.e. we can experience cooler climates in the higher latitudes. This can be understood by connecting it to the insolation. The Sun’s rays fall vertically on the equator, which heats the region intensely. Due to the Earth's spherical shape, the rays are inclined on the regions away from the equator and near the poles. In the region where there is inclined radiation, the heating is comparatively less. The vertical rays heat the Earth intensely compared to the inclined rays. Thus, the places near the equator are warmer than the places far away from the equator.

Altitude refers to the height above mean sea level. The temperature decreases at the rate of \(6.5°C\ per\ km\ \)(i.e. 1000m) of height. This is called the Normal lapse rate. So, places at a higher altitude have a lower temperature. This is the reason why hill station like Ooty has cooler weather even during summer.

 

The climate of a place varies with its proximity to the sea. Due to moderating effect of winds from the sea, places near the coast experience equable climate. Places located inland, far away from the sea, do not experience the sea's moderating influence. Such places experience a continental type (extreme) of climate.

 

Land surfaces are heated more quickly than water surfaces because of the higher specific heat of the water. In other words, for the same volume, land requires only \(1/3rd\ \)of the energy required by the water to raise the temperature by \(1°F\). This is why continental climate comes into play.

Based on the characteristics of wind, which is again based on where they blow, it makes the place warm and cold. Winds that blow from the sea (on-shore winds) often bring rain to the coast and dry weather to inland areas. In contrast, the off-shore winds bring dry weather.

If a wind blows from a warm region, it makes the place warm, and if blown from a cold region, it makes the place cold. 

Mountains can influence climate. Mountains receive more rainfall than the low-lying regions because the mountains act as natural barriers for the wind, so it is forced to ascend. On ascending, it cools, condenses and precipitates. It also prevents the entry of cold winds into the country or the escape of monsoon winds, thus greatly influencing the climate.

 

The windward is the side of a mountain that faces the prevailing wind, receives heavy rainfall. Whereas the leeward side of the mountain is the side sheltered from the wind, receives very little rainfall.

Cloud cover is an important component of understanding and predicting the weather as it reflects a large amount of solar radiation (albedo of clouds). Preventing the entry of heat into the Earth’s surface clouds helps regulate the temperature in a region. So, in cloudless areas generally (like the deserts), the temperature is very high. On the other hand, under the cloudy sky, the temperature is low.

 

Similar to that of winds, the ocean current also warms up or cools down the temperature of the nearby coastal areas. The warm ocean currents raise the temperature, whereas the cold current lowers the temperature of a place.

The canopy of a region also has a say in the climate of the region. The trees release water vapour into the air (via transpiration) and make it cool. Thus, forest areas have a lower range of temperature throughout the year in contrast to non-forested areas.