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Climate and Weather. ISCI 2001. Climate and Weather. Climate Zones. The Earth’s Atmospheres. Mostly nitrogen (78%) and oxygen (21%) Troposphere Temperature -50 to 40 Celsius Stratosphere Ozone layer (O 3 ) UV light. Greenhouse Effect.
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Climate and Weather ISCI 2001
The Earth’s Atmospheres • Mostly nitrogen (78%) and oxygen (21%) • Troposphere • Temperature • -50 to 40 Celsius • Stratosphere • Ozone layer (O3) • UV light
Greenhouse Effect • Terrestrial radiation ‘trapped’ by greenhouse gases • Carbon dioxide
Greenhouse Effect – Greenhouse Gases • (1). Carbondioxide • Fossil fuels; deforestation; organic decay; forest fires • (2). Ozone • Sunlight chemically reacts with O2 (natural) • Photochemical smog production • (3). Methane • Wetlands; biomass burning; termites; organic decay • (4). Chlorofluorocarbons • Refrigerants; aerosol spray propellants; cleaning solvents • (5). NitrousOxide • Fertilizers; burning of fossil fuels; forests; grasslands
Importance of Ozone • Absorbs UV radiation • Formed in the stratosphere • Chlorofluorocarbons (CFCs) • Ozone Holes
GH Effect Importance • Naturally warms the surface of the Earth • Keeps the average temperature of the Earth normal (sustain life) • -18 C otherwise • Global Warming • Increased GH effect, GH gases
Atmospheric Pressure • Density of air decreases with altitude • ‘thinning’ of air • Sea Level • 1cubic meter • Mass 1.2 kg (at 10 km 0.4 kg) • 101.3 kPa or 1 atmosphere of pressure • Barometer
How Winds are produced • Air that flows from high to low pressure areas • Uneven heat of the Earth’s surface • Warm air is lower density and low air pressure • Cool air higher density and higher air pressure • Isobars • Produces a convection current • Local winds • Small scale changes in convection cells and pressure gradients • Global wind patterns – prevailing winds
Coriolis Effect • Earth Rotation effects global wind patterns • Objects deviate from straight-line path including winds – deflected • Deflects winds to the right in the Northern Hemisphere and to the Left in the Southern Hemisphere • Jet Streams
Cloud Formation and Precipitation • Aggregates of water droplets formed by rising air that expands and cools • Cumulus, stratus or cirrus
Cirrocumulus Cirrostratus Altocumulus Cumulonimbus
Air Masses and Fronts • Air Mass • Arctic, polar, tropical • Weather Fronts • Warm vs Cold Fronts • Stationary • Animation
Formation of Cyclones • Hurricanes • Tornados