Presentation on theme: "The Atmosphere Essential Question: What is the significance of the atmosphere to the existence of life on earth? pp. 392-407."— Presentation transcript:
1 The AtmosphereEssential Question: What is the significance of the atmosphere to the existence of life on earth?pp
2 The AtmosphereThe atmosphere is the layer of gases and other particles that surround earth much like the peel of an apple covers it.
3 Benefits of atmosphere for humans include: provides gases like oxygentraps heat energy from sun which keeps us warm and water in a liquid stateprotects from UV rays & most meteoroids
4 Properties of Air in the Atmosphere Air also has pressureAir molecules push on objects from all directionsAs altitude increases air pressure and density decrease because its molecules are spread farther apartAir in the atmosphere has densityAir has mass because it is composed of atoms and moleculesAir has volume because it takes up spacedensity = mass/volume
5 Composition of the Atmosphere Nitrogen 78%Oxygen 21%All other gases 1%Tiny solid and liquid particles of:dustsmokesaltchemicals
6 Structure of the Atmosphere TroposphereStratosphereMesosphereThermosphereIonosphereexosphere
7 Troposphere 0-12 km above Earth’s surface Temperature varies For every 1km of altitude increase, temp decreases approx 6.5oCConstant -60oC in upper troposphereWhere weather occurs and most cloudsWhere hot air balloons travel
8 Stratosphere 12-50 km above Earth’s surface Temp in lower stratosphere about -60oCWarmer in upper stratosphere due to ozone layer which absorbs ultraviolet radiationWhere airplanes and weather balloons travel
9 Mesosphere 50-80 km above Earth’s surface Temp drops to -90oC in outer mesosphereWhere most meteoroids burn upSeen from Earth as shooting stars (meteors)
10 Thermosphere Everything 80km above Earth’s surface Temp up to 1,800oC Air very thinIncludes the ionosphere and exosphere
11 More on the Thermosphere Ionosphere80-550km above Earth’s surfaceRadio waves reflected from ionosphere to EarthAurora borealis (Northern Lights) occur in ionosphereExosphere550km - no limit above Earth’s surfaceSatellites orbit Earth in the exospherePhone signalsTelevision signals
12 Review Questions Air is invisible, so how does it have density? What significant role does the atmosphere have in providing us with water to drink?Air is invisible, so how does it have density?How does air pressure change as altitude increases? How does density change?Which layer of the atmosphere is the most important to you? Justify you reasons.
13 It is the layer of gases that surround the earth. What is the Atmosphere?It is the layer of gases that surround the earth.