WEATHER AND CLIMATE

Class 8- GEOGRAPHY

WEATHER AND CLIMATE

Difference between weather and climate

Weather is what conditions of the atmosphere are over a short period of time

Climate is how the atmosphere "behaves" over relatively long periods of time.

Today, the Sahara Desert in northern Africa is the largest desert in the world. However, several thousand years ago, the climate in the Sahara was quite different. This “Green Sahara” experienced frequent rainy weather. 

ELEMENTS OF THE WEATHER• A) Temperature is how hot or cold the atmosphere is, how many

degrees Celsius (centigrade) it is above or below freezing (0°C). Temperature is a very important factor in determining the weather, because it influences or controls other elements of the weather, such as precipitation, humidity, clouds and atmospheric pressure.

• b) Humidity is the amount of water vapour in the atmosphere. • c) Precipitation is the term given to moisture that falls from the air to

the ground. Precipitation includes snow, hail, sleet, drizzle, fog, mist and rain.

• d) Atmospheric pressure (or air pressure) is the weight of air resting on the earth's surface. Pressure is shown on a weather map, often called a synoptic map, with lines called isobars.

• e) Wind is the movement of air masses from high pressure areas (highs) to low pressure areas (lows).

WEATHER INSTRUMENTSWeather instruments are used to take measurements of

various atmospheric parameters at local weather stations

Hygrometer

This is a big word for the device that measures the humidity in the local atmosphere. Humidity is the percentage of water vapor in the surrounding air.

Thermometer

Everyone has probably heard of these. Thermometers are used in many places to measure temperature. If you get sick, that's one type of thermometer.

RAIN GAUGE

Instrument used to measure the amount of liquid precipitation over a certain length of time. In its

simplest sense, a rain gauge is nothing more than a can which collects water which falls from the sky as

rain.

BAROMETER

Atmospheric pressure is measured by barometers.  An aneroid barometer, one of the most common types, uses a sealed can of air to detect changes in atmospheric pressure.

ANEMOMETER

An anemometer is a type of weather instrument that measures wind speed. Some of these instruments measure both wind speed and wind direction. 

KÖPPEN CLIMATE CLASSIFICATION SYSTEMThe Köppen Climate Classification System is the most widely used for classifying the world's climates.

Most classification systems used today are based on the one introduced in 1900 by the Russian-German climatologist Wladimir Köppen.

Köppen divided the Earth's surface into climatic regions that generally coincided with world patterns of vegetation and soils.

annual and monthly averages of temperature

annual and monthly averages of precipitation

KÖPPEN CLIMATE CLASSIFICATION SYSTEM

KÖPPEN CLIMATE CLASSIFICATION SYSTEM

KÖPPEN CLIMATE CLASSIFICATION SYSTEM