Weather Forecast by Barometer


Weather forecast with barometer

The pressure at a certain place depends on the density of air at that place. As the temperature increases, the density decreases and so does the pressure. Also density depends on the amount of moisture present in air. The following are a few indications of change in temperature with change in barometric pressure,
1) If the barometric height suddenly falls, it is an indication of a coming storm.
2) If the barometric height falls gradually, it indicates possibility of rain
3) If the barometric height increases gradually, it indicates the advent of dry weather.
4) If the barometric height suddenly increases, this indicates flow of air from that place to surrounding area which will mean coming of extremely dry weather.


What is Barometer?

Barometer - Is it going to rain today? Is it going to stay fine? How can you tell about the weather behaviour?
One easy way is to measure air pressure and predict weather it will rain today or not.

1. If the air pressure is rising and its high then chances are it'll be a fine day.

2. If the pressure is falling, it's more likely to be wet, windy and dull.

The instruments that measure air pressure are called Barometers.
People have been using barometers for weather forecasting and research purposes.


Working of Barometer

The simplest kind of barometer is a tall closed tube standing upside down in a bath of mercury (a dense liquid metal at room temperature) so the liquid rises partly up the tube.
We use mercury in barometers because it's more convenient than using water. If you use water, you need a really tall tube and your barometer will be so enormous as to be impractical. But if you use mercury, you can get by with a much smaller piece of equipment, because density of mercury is higher then water.
 A piece of apparatus like this is called a 
Torricellian barometer