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1. AIR AND THE ATMOSPHERE

2. PLANNING FOR THE UNIT
 Main topic: WATER
 Properties of water
 Water cycle
 Hard water/soft water
 Ocean acidification
 Acid rain
 Eutrophication
 Main topic: AIR
 Properties of the atmosphere/air
 Oxygen
 The carbon cycle
 The (enhanced) greenhouse effect
 The ozone layer
 Main topic: Earth
 Nitrogen cycle
 Weathering & deposition (the rock
cycle)
 The short/long carbon cycle
 Fossil fuels

3. INTRODUCTION TO THE ATMOSPHERE

4. TASK
 Draw a mindmap of the atmosphere
 What is there and what happens in there?
 Show interactions with the other spheres (lithosphere/rocks, biosphere/life,
hydrosphere/water)

6. The atmosphere has not always
been like this, both abiotic and
biotic factors have caused huge
fluctuations.
Abiotic factors such as
temperature and precipitation.
Biotic factors such as plants and
animals.
Clues from:
• Sediments
• Fossils
• Gas trapped in ice
• Looking at other planets
Evolution of algae caused an
increase in oxygen (there was no
free oxygen before this).

13. ALBEDO EFFECT OF CLOUDS
 Albedo effect is to do with the amount of energy that a substance
reflects or absorbs.
 Linked to how white an object it.
 Clouds reflect and absorb a lot of solar energy.
 They also trap heat below them depending on how thick and high they
are.
 You may have noticed that cloudy nights are usually a lot warmer than
cloudless ones.

14. AIR CIRCULATION
 Rising air
 Warm and moist
 Low density
 Low pressure area
 Falling air
 Cool and dry
 High density
 High pressure area
 Forms circulations

15. CORIOLIS EFFECT
 Because of the spin of the earth
 Objects (air currents, water currents
deflect
 Makes storms swirl clockwise in the
Southern hemisphere and
counterclockwise in the Northern
Hemisphere

18. STRATOSPHERIC OZONE

20. STRATOSPHERE
 12-50 km high
 Temperature increases with altitude (gets warmer!)
 Horizontal winds (jet stream)
 Contains ozone layer

21. OZONE
 3 oxygen molecules

22. OZONE – O3
 Balance between two ongoing processes
 UV radiation passing through the Earth’s
upper atmosphere is absorbed by the
formation and destruction of ozone.

23. OZONE
 UV (ultraviolet) radiation is
absorbed during the formation
and destruction of ozone into
oxygen (O2)

24. OZONE AND UV LIGHT
 Allows UVa and UVb through, but blocks UVc waves
 UVa - causes wrinkles
 UVb - causes skin cancer
 UVc - worst one because of damage to organisms/tissues

25. UV RADIATION ALSO AFFECTS OTHER LIVING ORGANISMS
 Damage to photosynthetic
organisms.
 Especially phytoplankton – basis
of many aquatic food webs.

26. BENEFICIAL EFFECTS OF UV
 In animals stimulates the production of Vit D
 Treat psoriasis and vitiligo (skin diseases)
 Steriliser, water purifier
 Forensics, lighting, lasers

27. DAMAGE TO THE OZONE LAYER
 CFCs are usually very stable. However, in the high stratosphere the
UV radiation breaks them down releasing free chlorine atoms
(chlorine is very reactive).

28. HOGS (HALOGENATED ORGANIC GASES)
 HOG’s are usually stable but break down into halogen atoms (F, Cl, Br, I, At)
which are highly reactive
 Ex. (CFC = chlorofluorocarbon)
 Cl and F are halogens
 Organic = contains carbon

29. DEPLETION OF OZONE

30. DAMAGE TO THE OZONE
Substance Use/source Kind of atom
released
Chlorofluorocarbons (CFCs or
freons)
Hydrochlorofluorocarbon (HCFCs)
Halons
Methyl bromide
Nitrogen Oxides (NO, NO2, N2O,
NOx)
ODS (Ozone-depleting substances)

31. DAMAGE TO THE OZONE
Substance Use/source Kind of atom
released
Chlorofluorocarbons (CFCs or
freons)
Propellants in spray
cans, plastic foam
expanders, refrigerants
Release chlorine
atoms
Hydrochlorofluorocarbon (HCFCs) As replacements for
CFCs
Release chlorine
atoms,
Stronger GHG
Halons Fire extinguishers Release bromine
atoms
Methyl bromide Pesticide Releases chlorine
and bromine atoms
Nitrogen Oxides (NO, NO2, N2O,
NOx)
Bacterial breakdown of
nitrates and nitrites in
the soil (intensive).
High-flying supersonic
aircraft
The nitrogen oxides
are converted to NO,
which reacts with
ozone
ODS (Ozone-depleting substances)

32. SOURCES OF CFC’S
 Fire extinguishers, refrigerators, AC units

33. TROPOSHERIC OZONE

34. SMOG FORMATION
 Primary pollutants
 Burned fossil fuels
 Volcanic eruptions
 Particulate matter (PM)
 CO, CO2, NO, NO2, SO2
 Secondary pollutants
 A reaction has taken place with primary pollutants and light
 Tropospheric ozone

36. FORMATION OF TROPOSPHERIC OZONE
 Long set of reactions
Occurs in air
Made in combustion

37. EFFECTS OF OZONE
 Toxic gas and oxidising agent
 Damage to plants
 Degrades chlorophyll
 Damage to humans
 Breathing problems
 Throat, eyes and nose irritation
 Damage to things
 Car tires, fabrics, some plastics

38. FORMATION OF PHOTOCHEMICAL SMOG

39. FORMATION OF PHOTOCHEMICAL SMOG

40. FORMATION OF PHOTOCHEMICAL SMOG
 Factors that affect formation:
 Local topography
 Climate
 Population density
 Fossil fuel use
 Thermal inversion

41. EFFECTS OF PHOTOCHEMICAL SMOG