Atomoshpere Composition and strucure presentation

Atomoshpere Composition and strucure presentation

1. ATMOSPHERE- COMPOSITION AND STRUCTURE BS Lecture 7 th semester Department of chemistry GDC Gulabad By Ata ur rahaman

2. Atmosphere- composition & Structure Ata ur rahman The present condition and properties of earth’s atmosphere are one of the main reasons for earth to support life The atmosphere is the blanket of gases or vapours that surrounds the earth, and held together by the force of gravity .

3. Atmosphere- composition & Structure ata ur rahman

4. Atmosphere- composition & Structure Ata ur rahman GENERAL CHARECTERISTICS OF THE ATMOSPHERE Air has weight and the pressure it exerts is known as atmospheric pressure . Atmospheric pressure is a climatic element . At sea level the pressure is 1034 gram per square cms . (14.7pound per square inch.) Air is colourless , odourless , and tasteless . It is mobile , elastic , and compressible We cannot feel its presence unless there is horizontal motion in it…….WIND

5. Atmosphere- composition & Structure Ata ur rahman Importance of atmosphere

6. Atmosphere- composition & Structure Ata ur rahman Atmosphere maintains the level of water and radiation in the Earth system

7. Atmosphere- composition & Structure Ata ur rahman Constant gases are the ones, whose concentrations do not change over time, and their concentrations almost remain same . COMPOSITION OF ATMOSPHERE The composition of the atmosphere are gases present in large amounts, water vapour and solid particles in considerably less amounts . Gases constant gases variable gases Variable gases are present in different concentrations at different places and times.

8. Atmosphere- composition & Structure Ata ur rahman COMPOSITION OF ATMOSPHERE Gaseous composition of the atmosphere is usually expressed by percentage volume, that is, each gas’s relative part of the total mixture Major gaseous composition 78% nitrogen (N2), 21% oxygen (O2), and 0.9% argon ( Ar ). These three gases together make up 99.9% of the atmosphere Trace gases water vapor ( H 2 o), Carbon Dioxide (CO2), Neon (Ne), Helium (He), Methane (CH 4 ), Krypton (Kr), and Hydrogen (H 2 ) The concentration of gases in the atmosphere is measured in parts per thousand ( ppt ), parts per million (ppm) and parts per billion (ppb).

9. Atmosphere- composition & Structure Ata ur rahman Full Name Formula % Volume # Of Parts Unit Variable? Nitrogen N 2 78.1% 78 parts per Hundred   Oxygen O 2 20.9% 21 parts per Hundred   Argon Ar 0.934% 9 parts per Thousand   Water Vapor H 2 0.04% 400 parts per million variable Carbon Dioxide CO 2 0.0369% 370 parts per million   Neon Ne 0.00182% 18 parts per Million   Helium He 0.000524% 5 parts per Million   Methane CH 4 0.0001842% 2 parts per Million   Krypton Kr 0.000114% 1 part per Million   Hydrogen H 2 0.0001% 1 part per million variable Nitrous Oxide N20 0.0000315% 315 parts per billion   Carbon Monoxide CO 0.00002% 200 parts per billion variable Xenon Xe 0.0000087% 87 parts per billion   Ozone O3 0.000005% 34 parts per billion variable Sulphur Dioxide SO2 0.000002% 20 parts per billion variable Ammonia NH3 0.000002% 20 parts per billion variable Formaldehyde CH20 0.000001% 10 parts per billion variable Nitrogen Dioxide NO2 0.0000003% 3 parts per billion variable Nitric Oxide NO 0.0000003% 3 parts per billion variable Hydrogen Sulfide H2S 0.0000002% 2 parts per billion variable Hydrochloric Acid HCl 0.00000015% 2 parts per billion variable Nitric Acid HNO3 0.0000001% 1 part per billion variable

10. Atmosphere- composition & Structure Ata ur rahman Methyl Chloride CH3Cl 0.00000006% 600 parts per trillion   Freon-12 CF2Cl2 0.0000000544% 546 parts per trillion   Carbonyl Sulfide COS 0.00000005% 500 parts per trillion   Freon-11 CFCl 3 F 0.0000000263% 263 parts per trillion   Carbon Tetrachloride CCl4 0.000000098% 97 parts per trillion   Freon-113 C2F3Cl3 0.000000082% 82 parts per trillion   Methyl Chloroform CH3CCl3 0.000000056% 47 parts per trillion   HCFC-22 CHClF2 0.0000001525% 153 parts per trillion   HFC-23 CHF3 0.0000000011% 23 parts per trillion   Sulphur Hexaflouride SF6 0.000000004% 5 parts per trillion   Perfluoroethane C2F6 0.000000004% 4 parts per trillion   Triflouromethyl Sulphur Pentaflouride SF5CF3 0.00000000012% .12 parts per trillion   Sources 1. McGraw-Hill Encyclopedia of Science and Technology, 1987, McGraw-Hill, Inc. 2. Carbon Dioxide Information Analysis Center

11. Atmosphere- composition & Structure .Ata ur rahman The gaseous area surrounding the planet is divided into several concentric strata or layers . About 99% of the total atmospheric mass is concentrated in the first 20 miles ( 32 km ) above Earth’s surface. There are two types of atmospheric structures such as: 1. Thermal structure 2. Magneto-electronic structure . Structure of Atmosphere

12. Atmosphere- composition & Structure Ata ur rahman Atmospheric layers are characterized by variations in temperature resulting primarily from the absorption of solar radiation ; visible light at the surface, near ultraviolet radiation in the middle atmosphere , and far ultraviolet radiation in the upper atmosphere. THERMAL STRUCTURE

13. THERMAL STRUCTURE OR Vertical structure of Atmosphere Exosphere Thermosphere Mesosphere Stratosphere Troposphere

14. Atmosphere- composition & Structure Dr. Ata ur rahman

15. Atmosphere- composition & Structure Ata ur rahman Bottom layer of the atmosphere 70% mass of the atmosphere Extends to an average height of 5-20 km T hickness varies with latitude : poles about 8 km ; about 16 km above the equator Temperature decreases with height in this layer The rate of decrease of temperature with altitude is called , lapse rate . Average lapse rate in troposphere is -6.4 °C / km Troposphere ends at tropopause . Tropopause is just like a lid over the troposphere , where temperature stops decreasing with height Troposphere

16. Atmosphere- composition & Structure . ata ur rahman Stratosphere

17. Atmosphere- composition & Structure Ata ur rahman

18. Atmosphere- composition & Structure Ata ur rahman On the average, the temperature decreases about 6.5 O C/1,000 km, which is known as the observed lapse rate. An inversion is a layer of air in which the temperature increases with height.

19. Atmosphere- composition & Structure Ata ur rahman

20. Atmosphere- composition & Structure Ata ur rahman Mesosphere

21. Atmosphere- composition & Structure Ata ur rahman Thermosphere

22. Atmosphere- composition & Structure Ata ur rahman Exosphere

23. Atmosphere- composition & Structure Ata ur rahman   The ionosphere is defined by atmospheric effects on radiowave propagation as a result of the presence and variation in concentration of free electrons i n the atmosphere Ionosphere D-region is about 35 to 55 miles (60 - 90 km) in altitude but disappears at night. E-region is about 55 to 90 miles (90 - 140 km) in altitude. F-region is above 90 miles (140 km) in atitude . During the day it has two regions known as the: F1-region from about 90 to 115 miles (140 to 180 km) altitude F2-region in which the concentration of electrons peaks in the altitude range of 150 to 300 miles (around 250 to 500 km).