Wind is formed by the simultaneous action of three forces: horizontal pressure gradient force, geostrophic deflection force and friction force. The only factors that affect the size of wind force are friction force and horizontal pressure gradient force. Geostrophic deflection only affects the direction of the wind.
How to judge the wind force
The wind force depends on the isobars chart. The greater the pressure difference at the same distance (the denser the isobars), the greater the wind force. The speed of the wind. The intensity of the wind expressed as wind magnitude. The stronger the wind, the greater the wind level. The wind has both size and direction. Therefore, the wind forecast includes wind speed and wind direction. The magnitude of wind speed is often expressed by several levels of wind. The level of wind is determined based on how much the wind affects objects on the ground. How to judge the wind direction
1. Use the sea level isobars distribution chart to judge.
If in the picture, place A is the high-pressure center and place B is the low-pressure center, then northwest wind prevails in place ① and southwest wind prevails in place ②.
Northern Hemisphere sea level isobars distribution map
2. Use cyclone and anticyclone maps to judge.
For example:
Diagram of Northern Hemisphere Cyclones
When judging the wind direction, pay attention to the direction of the cyclone. Generally, the southerly wind blows below the cyclone and the northerly wind blows above it; the westerly wind blows on the left side of the cyclone, and the easterly wind blows on the right side of the cyclone.
3. Use the relationship between boiling point and air pressure to judge.
For example: M and N are 99.8°C. Neglecting sea level friction, the wind direction at O ??is (B)
A ． North wind b. South wind C. east wind d. Westerly wind
4. Use the characteristics of monsoon climate to judge.
In my country, northerly winds blow mainly in winter and southerly winds blow in summer; in South Asia, northeasterly winds blow in winter and southwesterly winds blow in summer.
5. Use temperate maritime climate and Mediterranean climate to judge.
The temperate maritime climate has westerly winds blowing all year round, southwesterly winds in the northern hemisphere, and northwesterly winds in the southern hemisphere. Mediterranean climate with westerly winds blowing in winter.