The Atmosphere and Atmospheric Energy Chapter 3 and 4

Transcription

1 The Atmosphere and Atmospheric Energy Chapter 3 and 4

2 Size of the Earth s Atmosphere Atmosphere produced over 4.6 billion years of development Protects us from radiation Completely surrounds the earth From surface to 300 miles Most of it s mass is at very low altitude

3 Composed of concentric layers each with it s own properties and purposes Troposphere Stratosphere Mesosphere Thermosphere 3

4 Composition of the Atmosphere Nitrogen Oxygen Water Vapor Carbon Dioxide Ozone

5 Variable Atmospheric Components Natural Air Pollutants Volcanoes, forest fires, plants, decaying byproducts, soil, oceans Human made air pollutants Carbon monoxide, Nitrogen Oxide, Ozone, sulfur oxides, volatile organic compounds, particulate matter, carbon dioxide, methane, water vapor 5

6 Solar Energy Sun only significant source of energy for the Earth s atmosphere 8 minutes Sun to Earth Electromagnetic radiation (radiant energy) Visible light, microwaves, X-rays, radio waves Electromagnetic Spectrum Visible light - light we can see (47% solar energy) Ultraviolet - absorbed by the ozone layer Infrared - 45% of solar energy

7 Transmission Energy Essentials The passage of shortwave and long wave energy through the atmosphere or water. Insolation - Incoming solar radiation Mixed reception of solar energy heats the surface of the earth. Reflected off atmosphere Pass through the atmosphere where it can be transformed before or after reaching the Earth s surface 7

8 Scattering - the deflection of light waves by gas molecules and particulate matter. Wave sent in random direction Blue and violet waves are shortest and scattered more easily Red and yellow waves are longest and harder to scatter When lots of particulate matter in the atmosphere, everything scattered

9 Albedo is the reflective quality of a surface. Different objects reflect different amounts of light Darker colors have higher albedo and absorb more energy Reflection A portion of the arriving energy is reflected back into space without being absorbed Absorption The assimilation of radiation by matter 31% of suns energy is absorbed by the earth

10 The Greenhouse Effect Long wave radiation absorbed by carbon dioxide and emitted back to the earth. Warms the troposphere Too much carbon dioxide, earth heats up too much Too little, earth cools too much 10

11 Conduction is the transfer of heat energy as it diffuses through a surface Different materials conduct heat at different rates Convection is the physical movement of gas and liquid Atmospheric and oceanic circulation 11

12 Temperature Heat and temperature are not the same a measure of the warmth or coldness of an object or substance with reference to some standard value. We feel the effect as the heat transfer between warmer and cooler objects Temperature Scales Fahrenheit - US Ice melts at 32 degrees Water boils at 212 degrees Celsius - Everyone else Ice melts at 0 degrees Water boils at 100 degrees 12

13 Weather and Climate Weather is short term atmospheric conditions Climate is the aggregate of day-to-day weather conditions over a long period of time. At least 3 decades of data Climate is a significant factor in the physical landscape Soil, vegetation, animal life, water and topography

14 Variations in The Heating of The Earth Influenced by attributes of our planet Overlap and interact with each other Latitude Changing amount of sunlight heats the earth unevenly Temperature strongly influenced by latitude

15 Angle of Incidence The angle at which the sun strikes the Earth s surface If ray strikes the earth vertically, energy is concentrated If ray strikes the earth obliquely, energy is spread out The smaller the area, the more efficient the heating

16 Land-Sea distribution Oceans heat and cool slower than land Maritime locations (Seattle) experience milder temperatures than continental locations (North Dakota) Oceans = higher humidity Northern Hemisphere has much more land mass General Circulation of the Atmosphere Semi-permanent pattern of winds

17 General circulation of the Oceans General pattern of movement Influences coastal climates Warm currents off east coast Cool currents off west coast

18 Altitude Temperature, pressure and moisture decrease Significant ramifications for many climatic characteristics Topographic Barriers Divert windflow Windward vs Leeward sides

19 Latitude Land-sea Westerlies Topographic barriers Average annual temperature 32.9

20 The Urban Environment and Temperature Nearly 50% of the worlds population lives in cities Urban heat island Higher temperatures than nearby rural areas Urban areas heated by asphalt and glass, buildings, pollution and human activity 20

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