Class 7 wind

wind

1. Observation of Wind speed and direction

2. Wind Wind is air in motion. Winds are made up of a series of gusts and eddies that can be felt but not seen. The speed of wind is recorded in kilometers per hour.

3. The factors determining the direction and speed of wind are as follows: 1. The pressure 2. Rotation of the earth 3. Friction or obstacle

4. 1. The pressure Differential heating of earth produces high pressure and low pressure. Winds are always attracted towards low pressure from high pressure regions.

5. 2. Rotation of the earth Due to the speed of rotation of the earth the winds are deflected towards the right in northern hemisphere and towards the left in southern hemisphere. The force which make the atmosphere to deflect is called as coriolis force.

6. 3. Friction or obstacle The wind velocity depends on the friction or barrier it faces. The winds blow with great velocity in the deserts or over the oceans where there is no obstruction.

7. Weather maps

8. Isotherms On a weather map the lines connecting the places of same temperature is called Isotherms.

9. Isobars On a weather map the lines connecting the places of same pressure is Isobars.

10. Isohyet On a weather map the lines connecting the places of same rainfall is called Isohyet.