The Atmosphere Weather Dynamics Science 10 Source: Nelson Science 10 Text 13.4 ~ Page 510 Approx. 30 minutes Presentation Time Image from:

Atmosphere Consult diagram on page 511 Consult diagram on page 511 It surrounds us (wind, the sky, when you take a breath) It surrounds us (wind, the sky, when you take a breath) “is the blanket of air and moisture that surrounds Earth” (Nelson Science ). “is the blanket of air and moisture that surrounds Earth” (Nelson Science ). Most dense at sea level, less dense higher in the atmosphere Most dense at sea level, less dense higher in the atmosphere At approx. 500km above the surface of the earth, there are very few molecules left and space begins. At approx. 500km above the surface of the earth, there are very few molecules left and space begins.  (510)

Layers... Altitude: “the height above sea level, usually measured in metres (m) or kilometres (km). (Altitude can also be called elevation.)” (Nelson Science ). Altitude: “the height above sea level, usually measured in metres (m) or kilometres (km). (Altitude can also be called elevation.)” (Nelson Science ). Are thickest at the equator Are thickest at the equator –Air is warmer above the equator and expands = takes up more room –Air at the poles is colder and takes up less room.  (Nelson 510)

Astronomy

Troposphere: –Closest to earth’s surface –Up to 16 km at equator (8km at poles) –Contains most of the moisture –Responsible for our weather patterns –Temperature decreases as altitude increases  (Nelson 510) –Troposphere Images

Tropopause –Temperature rises because of ozone (absorbs energy from the sun) –Temperature difference keeps layers separated  (Nelson 511)

Stratosphere: –Dry layer –12-50 km –Highest concentrations of ozone This ozone layer helps to protect the earth from harmful uv rays. This ozone layer helps to protect the earth from harmful uv rays. –Temperature of this layer increases with altitude. –** Ozone near the ground in not helpful like it is in the upper atmosphere.  (Nelson Science ) –Stratosphere

Mesosphere –Middle layer –50-80 km –Low temperature –Low density of gases –All parts of the atmosphere up to this point (except for water vapour and ozone concentrations) are fairly similar in make up.  (Nelson Science ) –Mesosphere:

Thermosphere (Ionosphere) – km –Low density –Molecules have more energy = higher temperature –X-rays are absorbed in this layer (part of the reason the temperature is higher) –Ionosphere: higher energy radiation from the sun causes particles to become electrically charged i.e. Auroras (Northern/Southern Lights) i.e. Auroras (Northern/Southern Lights)  (Nelson Science )

Examples of Auroras Auroras: the Northern and Southern Lights ect/earth/aurora.html Auroras: the Northern and Southern Lights ect/earth/aurora.html Southern Lights (Aurora Australis) – Taken from the Space Shuttle EndeavourAurora Australis

Website Examples of Auroras Michigan Tech – Aurora Page Michigan Tech – Aurora Page – Auroras – The Northern and Southern Lights Auroras – The Northern and Southern Lights – /aurora.html /aurora.htmlhttp://csep10.phys.utk.edu/astr161/lect/earth /aurora.html

Exosphere –“thin outermost layer of the atmosphere” (Nelson Science ). –Up to 800km above the surface of the earth. (Wikipedia Atmosphere). –There are a few hydrogen particles widely spaced apart. –Can be considered “space”  Nelson Science –Exosphere:

Temperature Gradient –“the change of temperature over a distance” (Nelson Science ). For example, in the troposphere the temperature decrease -6 C for every 1000m. For example, in the troposphere the temperature decrease -6 C for every 1000m. Other layers are less consistent Other layers are less consistent  Nelson Science

Supporting Life –The atmosphere provides: Oxygen & Nitrogen = support life Oxygen & Nitrogen = support life Carbon dioxide = needed by plants for photosynthesis Carbon dioxide = needed by plants for photosynthesis Ozone absorbs UV radiation Ozone absorbs UV radiation Part of the water cycle Part of the water cycle Protection from meteorites (burn up in the atmosphere because of the friction) Protection from meteorites (burn up in the atmosphere because of the friction) Helps keep the average temperature in a range that can support life. Helps keep the average temperature in a range that can support life. Water vapour and carbon dioxide trap heat energy from the ground Water vapour and carbon dioxide trap heat energy from the ground Circulates air to maintain an energy balance Circulates air to maintain an energy balance  (Nelson Science )

Atmospheric Pressure –“the pressure the air exerts as gravity pulls it toward the centre of Earth” (Nelson Science ). –Highest at sea level = particles closest together –Higher altitudes = less pressure –Depends on other factors i.e. if air is rising or falling. –Pressure Gradient: “a measure of the amount the atmospheric pressure changes across a set distance. Pressure gradients can be vertical or horizontal” (Nelson Science ). “a measure of the amount the atmospheric pressure changes across a set distance. Pressure gradients can be vertical or horizontal” (Nelson Science ).  Nelson Science

Refer to page 512 to examine ways of representing atmospheric pressure. Refer to page 512 to examine ways of representing atmospheric pressure. Kilopascals (kPa) 1kPa = 1000 Pa Kilopascals (kPa) 1kPa = 1000 Pa Measured by a barometer Measured by a barometer Scientists use ballons with a radiosonde (has electronic sensors (temp, press, water vap) info is sent back to earth using radio signals.) Scientists use ballons with a radiosonde (has electronic sensors (temp, press, water vap) info is sent back to earth using radio signals.)  Nelson Science

Websites to View: Astronomy 161 The Solar System Astronomy 161 The Solar System –

Heat Transfer... revisited Consider the following: Consider the following: –Only 30% of the earth’s surface is land –Clouds often cover much of the surface –Most solar energy interactions occur with water –“Lakes, rivers and oceans absorb 93% of incoming solar radiation that reaches their surfaces” (Science Power ). (Science Power )

Specific Heat Capacity –“the amount of heat that is required to raise the temperature of 1 gram of a substance 1 degree Celcius” (Science Power ). –Large specific heat capacity = smaller temperature increase –“water increases much less than the temperature of most similar substances after absorbing the same amount of energy” (Science Power ). –Examples of Specific Heat Capacity (J/g C): Pure water 4.18 Pure water 4.18 Dry air 1.00 Dry air 1.00 Brick 0.84 Brick 0.84  Science Power

Text Questions: Text Questions: –Page 513 # 5, 6, 7