The wind is formed as a result of the radiation from the sun, which is absorbed differently on the earth’s surface. Cloud cover, mountains, valleys, water bodies, vegetation, and desert lands all contribute to the heating of the planet’s surface in various ways.
As a result of this uneven heating, earth surfaces are bound to vary greatly in temperature. Air on surfaces with higher temperatures will then begin to rise because it is lighter (less dense).
Low atmospheric pressure is created as the air rises. And Air on surfaces with cooler temperatures sink (do not rise). The sinking creates higher atmospheric pressure.
What is the meaning of wind direction?
The first and most important thing to remember is that wind direction is always determined by where the wind blows FROM rather than where it blows TO.
The direction of the wind is typically reported by the direction from which it originates. A north or northerly wind, for example, blows from north to south. Onshore winds (sea breeze) and offshore winds are the exceptions (blowing off the shore to the water).
Wind direction is usually calculated in cardinal (or compass) degrees. As a result, a wind blowing from the north has a wind direction of 0° (360°); a wind blowing from the east has a wind direction of 90°, etc.
Weather forecasts normally give the direction of the wind along with its speed, for example, a “northerly wind at 20 km/h” is a wind blowing from the north at a speed of 20 km/h
The thing to understand is that wind direction is defined as the orientation of the wind’s movement. For example, if the wind is blowing from the southeast and heading northwest, it is referred to as a southeast wind.
The four cardinal points are marked with their initials in the wind rose: North (N), South (S), West (W), and East (E) (E).
These are, however, simple directional names that almost never correspond to a real-world wind direction.
Winds are constantly shifting, and they do not always blow in the same direction as human-designed tables.
There are four other intercardinal directions to improve the quality of the readings: Northeast (NE), Southeast (SE), Northwest (NW), and Southwest (SW) (SW).
The windsock and wind vane are examples of instruments that can be used to measure wind direction. Both instruments work by moving in order to reduce air resistance.
Anemometers and wind vanes are modern instruments used to measure wind speed and direction. The wind energy industry employs these instruments for both wind resource assessment and turbine control.
What are the Different Ways to Measure Wind?
The wind has both speed and direction; two different equipment are used to measure this parameter:
Anemometers are a type of weather station instrument that measures wind speed. There are several types of anemometers, including cup anemometers, hot wire anemometers, windmill anemometers, sonic anemometers, and laser doppler anemometers.
Wind vanes are also known as weather vane, which is used for determining the direction of the wind.
Categories of Winds
Primary Wind is also known as Planetary Wind
Throughout the year, primary winds constantly blow in a particular direction. Primary winds can also be referred to as prevailing winds or planetary winds. Also, the primary winding is classified into three types: trade winds, westerlies, and easterlies.
Secondary Wind or Periodic Wind
Secondary winds are those that change direction with the seasons. Secondary winds occur in many locations throughout the world. A particular secondary wind and the underlying physical forces that drive the wind depends upon the unique geographic location. The monsoon wind is one of the most well-known secondary winds.
Tertiary Wind or Local Wind
Tertiary winds blow only during a particular period of the day or year in a small area. The difference in temperature and air pressure of a specific location causes these winds to blow. According to local characteristics, these winds can be hot, cold, ice-filled, or dust-rich.