Wind vane
Also called: Weather vane · Topic: Atmospheric Pressure, Winds and General Circulation · NCERT: Class 7, Ch 2 "Understanding the Weather"
Meaning
A wind vane, also called a weather vane, is an instrument that shows wind direction. It has an arm that turns freely on a rod. The wind pushes its broad tail away, so the pointer turns to face the direction the wind is coming from. A wind sock is a cloth cone that does the same job at airfields. It also hints at strength, because it fills out more in stronger wind.
Example
In Kerala during the south-west monsoon, a wind vane points towards the south-west, because the moist wind comes from the Arabian Sea in that direction.
Don't confuse with
- Anemometer: this measures wind speed with spinning cups, not direction.