Lesson 1.1 & 1.2 of the Science Project Hamad al Mubaraki Tameem al Khezzi Basil Qabandi & Ibrahim al Melhem

Lesson 1.1: Earth’s atmosphere supports life

Introduction Atmosphere: A whole layer of air that surrounds Earth Supports life and protects it Important, but thin Without the atmosphere, the oceans would not exist & life would not survive

The Atmospheres Characteristics Altitude: The distance above sea level The air becomes thinner as altitude increases The thickness or thinness of air is measured by its density Quick Review; Density: The amount of mass in a given volume of a substance

The Atmospheres Materials Most of the materials in the atmosphere are gases 78% of the gas is nitrogen, 21% of the gas is oxygen, argon, carbon dioxide and other gases make up 1% of the gas It also contains tiny particles of solid or liquid such as dust.

Quick review of cycles Cycles: A physical and/or chemical process in which one material continually changes locations and/or forms Three of the most important cycles that affect the atmosphere are the carbon,nitrogen, & water cycle

Sudden Changes in the Atmosphere Dramatic events may cause changes in the atmosphere It takes time before the atmosphere is able to restore balance Three of these dramatic events are: Volcanic Eruptions Forest Fires Dust Storms

Volcanic Eruptions Volcanoes shoot gases and huge amounts of ash into the atmosphere which produces haze that affects the air and lower temperatures

Forest Fires When forests burn, the carbon inside the trees combines with oxygen and enters the atmosphere as carbon dioxide. Wood ash also enters the atmosphere.

Dust Storms Water,wind, or drought can separate soil, powerful windstorms raise clouds of this seperated soil, these storms add huge amounts of particles in the air for a time.

Lesson 1.2: The Sun supplies the atmosphere’s energy

Introduction Almost all the energy around you comes from the Sun Most of this energy reaches the Earth in a form you can see-visible light Two things happen to the sunlight that reaches Earth, some is reflected and others are absorbed

Reflected Sunlight The reflected sunlight is sent to a new direction You see most of the objects around you by reflected light Sand is an example of this; the Sun hits it and makes it have bright colors

Absorbed Sunlight The energy from this light heats the substance that absorbs it Sand that absorbs the sunlight that hits it can become warm or even hot

Solar Energy Radiation: energy that travels across distances in the form of certain types of waves About 30% of the solar radiation that reaches Earh is reflected, the other 70% is absorbed

Solar Radiation About 5% of solar energy is reflected by Earth’s surface About 25% of solar energy is reflected by clouds and Earth’s atmosphere About 20% of solar energy is absorbed by clouds and the atmosphere About 50% of solar energy is absorbed by Earth’s surface

The atmosphere moves energy The air absorbs solar energy and moves it around and spreads it out unlike the sand which absorbs solar energy and stores it in one place. Three processes that move energy from place to place are: Radiation Conduction Convection

Radiation Earth’s surface gives off a type of invisible radiation, called infrared radiation that can be absorbed by certain gases Sunlight warms the ground The energy from the radiation arms the air and the air has infrared radiation

Conduction Conduction: the transfer of heat energy from one substance to another by direct contact Earth’s surface transfers energy to the atmosphere by conduction, such as when hot beach sand warms the air above it The warm ground heats the air

Convection Convection: the transfer of energy from place to place by motion of gas or liquid Cool, dense air sinks downward and pushes air out of the way,warm air carries energy upward

It’s a cycle of radiation ! First,radiation from the Sun warms the sand Second, the hot sand conducts energy to the air Third, the warm air carries energy up in convection

Temperature layers of the atmosphere Different parts of the atmosphere absorb and move energy other than density Four layers of the atmosphere are: Troposphere Stratosphere Mesosphere Thermosphere

Troposphere The layer of the atmosphere nearest Earth’s surface Contains about 80% of the total mass of the atmosphere The troposphere is warmed from below by the ground Its from 0-6 miles upward & its temperature is from 15C - -60C

Stratosphere The layer of the atmosphere second nearest to the Earth’s surface Within the stratosphere are molecules of a gas called ozone which absorb a type of solar radiation that is harmful to life Its from 6-31 miles upward & its temperature is -60C - 0C

Mesosphere The third layer of the atmosphere that is nearest to the Earth’s surface Extremely thin, holds up 0.1% of the atmospheres mass Most meteors burn up within the mesosphere Heated from below, like the troposphere Its from 31 - 56 miles upward & its temperature is 0C - -85C

Thermosphere The layer of the atmosphere farthest from Earth's surface It becomes less and less dense upward until it is outer space The air high in this layer is very hot because the molecules absorb a certain type of solar radiation It is from 56 miles and up and its temperature is -85C and it increases