ATMOSPHERE 1 - Biosphere 2 - Atmosphere (Protective) layers 3 - Atmosphere (composition) 4 - ATMOSPHERE (LAYERS) 5 - Ozone

biosphere Earth is the only known planet with liquid water to form on its surface. Water is essential to life. Biosphere - All regions of the Earth where life can exist

BIOSPHERE In the biosphere – Living beings can interact with each other and with their environment. The biosphere consists of three parts: 1) the gas portion: the atmosphere (air) 2) The liquid part: the hydrosphere (water) 3) The solid part: the lithosphere (rock and sediment)

BIOSPHERE OUR BIOSPHERE

Atmosphere – protective layers The atmosphere is a gas envelope surrounding the Earth.

ATMOSPHERE – PROTECTIVE LAYERS Life would be impossible without the atmosphere. It protects the Earth by blocking ultraviolet rays of the Sun. It also destroys the meteors that are moving towards us, through friction. It reduces the temperature changes caused by the greenhouse effect. During the day, the temperature would rise to 80˚C During the night, temperatures would drop to -140˚C

Atmosphere - composition The air is a mixture of several gases essential to maintaining life. Clean air is a homogeneous mixture (solution), the two main gases are Nitrogen ( 𝑁 2 ) and Oxygen ( 𝑂 2 ). Water vapor and carbon dioxide are also present in the air, but in very small quantities. The air often contains dust (heterogeneous mixture)

ATMOSPHERE - COMPOSITION PERCENTAGES OF AIR COMPOSITION FOR OUR ATMOSPHERE NITROGEN 78% OXYGEN 21% WATER VAPOUR 0 to 3% CABON DIOXIDE .03% OZONE .000003% ALL OTHER GASES < 1%

ATMOSPHERE - COMPOSITION NAME CHEMICAL FORMULA PERCENTAGE ROLE NITROGEN 𝑁 2 78% TO HELP ANIMALS AND VEGETATION DEVELOP THEIR CELLULAR MEMBRANES (STABILIZER) OXYGEN 𝑂 2 21% CELLULAR RESPIRATION AND PHOTOSYNTHESIS WATER VAPOUR 𝐻 2 𝑂 0 to 3% PRESENCE OF WATER & MAINTAIN TEMPERATURES CARBON DIOXIDE 𝐶𝑂 2 .03% KEEPS ATMOSPHERE & EARTH WARM OZONE 𝑂 3 .000003% PROTECTS EARTH FROM UV RAYS ALL OTHER GASES NEON, HYDROGEN, HELIUM, KRYPTON, XENON, ARGON < 1% TRACES OF GASES HELP WITH VARIOUS THINGS

ATMOSPHERE - LAYERS The five layers of the atmosphere are: 1) The troposphere 2) The stratosphere 3) The mesosphere 4) The thermosphere 5) The exosphere

ATMOSPHERE - LAYERS

ATMOSPHERE – LAYERS TROPOSPHERE The closest to the surface layer of the Earth. The temperature decreases with altitude. The troposphere is the most important layer for living beings because it contains over 80% of all the air in the atmosphere. The more you move away from the Earth , the more air is scarce. The troposphere also contains most of the water vapor of the atmosphere. The steam gives birth to rain and clouds. The Weather Layer

ATMOSPHERE – LAYERS STRATOSPHERE It lies just above the troposphere. This is where we find the ozone layer (a layer of gas that absorbs the ultraviolet rays of the Sun). Ultraviolet rays are increasing the temperature of the stratosphere with altitude. Large aircraft generally fly in the stratosphere just above the clouds. The Ozone Layer

ATMOSPHERE – LAYERS MESOSPHERE It is the third layer of the atmosphere. The temperature decreases with altitude. It protects the earth against the meteorites. When meteorites come into contact with the air molecules, the friction heats them to the point that it will ignite and disintegrate. The Protective Layer

ATMOSPHERE – LAYERS THERMOSPHERE It is the fourth and final layer of the atmosphere. It is also the thickest of the four layers. The temperature increases with altitude. Auroras occur in the thermosphere. The Final Layer

ozone Since 1975, satellite images show that the thickness of the ozone layer has been decreasing. The most affected by the thinning of the ozone layer is the area above Antarctica. The cold temperatures favor the thinning.

OZONE

ozONE WHAT ARE THE CAUSES? The main causes of the thinning of the ozone layer: Chlorofluorocarbons (CFCs) In the stratosphere, chlorine (Cl) CFCs reacts with ozone. CFCs are found in: Aerosols, refrigerants (air conditioning, refrigerator, freezer, etc.) and some cleaning products CFCs are now banned.

OZONE Aerosol products (paints, deodorants, insecticides, shaving cream, whipped cream)

OZONE WHAT ARE THE CONSEQUENCES? The ozone layer protects us against ultraviolet (UV) rays of the Sun. The consequences of thinning include: An increased risk of skin cancer A greater risk of cataract (eye disease where the lens becomes opaque and prevents light from passing)

OZONE CONSEQUENCES

OZONE At low level (in the troposphere), ozone levels continue to rise. The increase in low-level ozone is caused by pollution.