Planetary Winds and Local Winds

There are mainly five types of wind present in our environment such as planetary, trade, westerlies, periodic and local winds. The present article discusses the concepts of planetary winds and local winds. By the end of the guide, an identification of the differences between the planetary wind and local winds could be assessed. In addition, it also provides information about the types of local winds present in our environment. 

Concepts of Local Winds and Planetary Winds

Local winds mainly occur in a smaller area within a given region whereas planetary winds are winds that blow on a global scale. Planetary winds are mainly three types such as trade winds, westerlies, and polar winds. The planetary winds blow from the high-pressure belt to the low-pressure belt. The name of the above-mentioned three types of planetary winds is given as per the direction from which they blow. For example, trade winds blow from east to west near the equator (30 degrees north to 30 degrees south). In addition, the polar winds blow from the east, which is an area of high pressure around the south and north poles. On the other hand, local winds blow across the area of surface ranging from a few kilometres to hundreds of kilometres over a region. The local scale winds are also known as regional winds and thus are in contrast to planetary winds. Local winds can be driven by variation in topography or by temperature and pressure differences. Local winds have different names in different countries and they are named as per their characteristics. For example, the name of the local winds in India is called loo, which blows over the plains of India and Pakistan. In addition, Kalbaisakhi is a type of thunderstorm that prevails in West Bengal and Assam, states in India. 

Types of Local Winds 

The main types of local winds are Foehn winds, katabatic winds, Anabatic winds, sea breezes, and land breezes. 

Anabatic winds: This type of wind is caused by the thermal process and it occurs over a mountain slope that gets heated by the sun. The air over the slope is warmed and expands upwards, after which it sinks and cools down over its neighbour valley. This type of wind blows at a speed of only 1-2 m/s and can increase the strength of the sea breeze. 

Katabatic winds: This wind occurs when air on the sloping surface is colder than the air present at the same level that is away from the hillside over the valley. They mostly tend to happen at night, as there is surface cooling. This occurs because of differential heating of the sea and the land. The speed of katabatic wind is 3-4 m/s and this wind can lead to the formation of frost, fog, and mist in the valley. 

Sea breeze: This type of wind blows during the daytime when the land becomes warmer than the sea. The warm air of the land expands by moving upwards, and then the cold air from the sea comes to fill up the vacant area thus it forms a cycle. This cycle is known as the sea breeze and blows at a speed of 4-8 m/s. 

Land breeze: This type of wind blows during the night time or in the early morning. At night time the air cools and contracts which increases the pressure over the land. This causes the movement of air from land to sea, where cold dry air from the land moves towards the sea and cool moist air from the sea comes to the land. This forms a cycle that is known as a land breeze. The speed of land breeze is around 2-3 m/s or lower than that.   

Difference between Planetary winds and Local winds

Conclusion 

The assessment has discussed planetary winds, local wind, from where, it can be concluded that there is a huge difference between planetary and local winds. This is because the planetary wind blows on a global scale, and local winds blow on a regional scale. In addition, different types of local winds can be summarized such as land breeze, sea breeze, and anabatic winds. On the other hand, planetary winds can be divided into three groups such as polar winds, westerlies, and trade winds. Local winds are mainly blowing from high-pressure areas to low-pressure areas. Loo is one of the most common local winds in India.