ATMOSPHERIC PRESSURE AND WINDS copy.pptx

Ppt on atmospheric pressure

1. ATMOSPHERIC PRESSURE AND WINDS BY – YUGAM SINGH RINNI Sanga SABHYATA.

2. LEARNING OBJECTIVES TO UNDERSTAND the ATMOSPHERIC PRESSURE. TO UNDERSTAND THE AIR-SYSTEM . TO learn THE WINDS AND ITS TYPES. TO UNDERTSTAND the working of ATMOSPHERIC PRESSURE.

3. WHAT IS AIR AIR CAN BE DEFINED AS LAYER OF GASES OR ATMOSPHERE WHICH IS NOT VISISBLE THROUGH OUR EYES BUT WE BREATHE . GASSES LIKE- CARBON,NITROGEN,OXYGEN AND ETC.

4. WHAT IS ATMOSPHERE THE ATMOSPHERE CAN BE DEFINED AS THE BALNKET OF AIR THAT SURROUNDS THE EARTH.

5. What is atmospheric pressure Atmospheric pressure ,also known as air pressure as its defined as the pressure in the atmosphere of the earth as the standard unit of the atmospheric pressure is (MILLIBAR) It’s the unit which is used to define the atmospheric pressure. The average air pressure on the earth is – 1013.25. The air around as that we breathe has weight in it and it compresses or presses each and everything that it touches and that is defined as the atmospheric pressure. As it’s the force exerted on a surface by the air above it as gravity pulls it on the earth.

6. WHAT IS THE TOOL WHICH IS USED TO MEASURE THE AIR PRESSURE. THE TOOL WHICH IS USED TO MEASURE THE AIR PRESSURE AROUND OUR ENVIORNMENT IS THE BARometer

7. THERE ARE TWO TUPES OF BAROMETERS MERCURY BAROMETER,ANERIOD BAROMETER Mercury barometer- it can be defined as the which is used to calibrate and check the aneroid barometers. Aneroid barometers- a non liquid barometer called as the aneroid barometer is widely used in portable instruments and in aircrafts altimeters because of its smaller size and CONVIVNCE Aneroid barometers

8. HOW BAROMETER IS USED As we all know that the atmospheric pressure is measured by barometer . in most commonly barometer has a column of mercury in a glass tube rises or falls as the weight of the atmosphere changes . as meteorologist describes the atmospheric pressure by high or low mercury rises or decreases. As when the (MILLIBAR) drops then the altitude decreases . and same as vice versa .

9. FACTORS AFFECTING THE ATMOSPHERIC PRESSURE. ATMOSPHERIC PRESSURE ON THE EARTH IS NOT UNIFORM IT VARIES FROM Place to place The three main factors are as follows Altitude Water vapor Temperature

10. Altitude ( height)

11. altitude is the height of an object above the surface of the ground or sea level Air pressure is the highest at sea level and decreases with altitude In the sky above the density of air decreases and so does the pressure exerted by it .

12. Water vapor

13.  It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Air containing more water vapor is lighter than the air which has little or no water vapor , and thus the air pressure decreases .

14. Temperature

15. When the temperature increases the air expands and its density decreases as a result the air exerts less pressure

16. Types of air The air can be classified into 4 main subheads as follows Hot air Dry air Cool air Moist air

17. Hot air and cool air Hot air When the temperature increases the air expands Density decreases the air becomes lighter Cool air When the temperature decreases The density increase the air becomes heavier .

18. Moist air and dry air Moist air Air which contain more water vapoUR Lighter Dry air Air which contain no water vapour or lesser Heavier

19. Permanent pressure belts . The horizontal distribution of atmosphere pressure is not uniform all over the globe .. There are seven permanent pressure on the planet earth … Equatorial low Two subtropical highs Two subpolar lows The two polar highs And the other two are in the northern and southern hemispheres.

20. PRESSURE BELTS AND ITS LOCATION ..

21. Why do pressure belts shift The pressure belts shift because due to earths revolution , the earths relative position with sun varies every year.

22. Why do pressure belts change. shifting of Pressure belts They shift northward in July and southward in January, following the changing position of the sun's direct rays as they migrate between the Tropics of Cancer and Capricorn. The pressure belts shift 5° northward when the sun shines vertically overhead on the Tropic of Cancer (21 June), and 5° southward when the sun shines vertically overhead on the Tropic of Capricorn (22 December) from their initial position. Seasonal climate fluctuations are caused by the movement of the pressure belts, especially between the latitudes of 30° and 40° in both hemispheres .Because of the changing of permanent belts southwards and northwards with the overhead position of the sun, this region has a Mediterranean climate .During the winter, Westerlies prevail, resulting in rain. During the summer, dry Trade Winds blow offshore, preventing rain from falling in certain areas . The pressure belts in both hemispheres stay balanced when the sun shines vertically over the Equator on March 21st and September 23 rd .

23. Winds Wind can be defined as the movement of air at high speed / caused by the uneven heating of earth by sun and its rotation ..

24. Types of winds .. The wind can be divided into 3 main types . Permanent winds. Seasonal winds. Local wind .

25. Permanent winds . They can be defined as those types of winds that blow allover the year and in a particular direction .. They can be broadly classified into 3 types as follows. trade Winds  – These are permanent winds flowing from east-to-west. It flows in the Earth’s equatorial region (between 30°N and 30°S latitudes). Easterlies  – It is a prevailing wind blowing from the east. The trade winds in tropical regions and the prevailing winds in the polar regions are easterlies. Westerlies  – These are prevailing winds that flow from the west towards the east. It flows in the Earth’s middle latitudes between 30 and 60 degrees latitude. Also called as anti-trades, these winds originate from the high-pressure areas in the horse latitudes and trend towards the poles and steer extratropical cyclones in this general manner.

26. Seasonal winds They can be defined as those winds that blow during a season.. For example the seasonal winds can defined as the monsoon winds .

27. Local winds Local winds occur due to the movement of air between high and low-pressure systems within small areas. For example- the land breeze and the sea breeze .

28. The concept of land and sea breeze ..

29. Land and sea breeze. LAND BREZZE- IT IS A SYSTEM CHARACTIRIZED BY WIND FLOWN FROM LAND TOWARDS SEA AT NIGHT TIME SEA BREZZE- a breeze blowing from sea towards land especially during the day when the warmth of land is at high. During day time.

30. Thank you