GEOG 1114 1st Edition Lecture 6 Outline of Last Lecture Introduction to Maps The tools of Geography Maps Continued Map Distortion Three Major Types of Map Projections Isolines Map Design Elements Geotechniques provide effective data a Cartography b Remote Sensing c Geographic Information Systems GIS Outline of Current Lecture Introduction to the Atmosphere Roles and Characteristics of the Atmosphere Characteristics Composition Atmospheric Particulates Aerosols Vertical Structure Pressure Composition of the Atmosphere Atmospheric Pressure Air Pressure Current Lecture Roles and Characteristics of the Atmosphere earth s unique atmosphere has several roles These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute It supplies oxygen Supplies carbon dioxide for plants Helps maintain earths weather supply Insulates Earth against temperature extremes Shields the Earth from too many ultraviolet rays Has a major effect on weather and climate Important transmitter of energy Characteristics The Atmosphere uniformly surrounds Earth is held down by Earth s gravity and Interacts with all components of the environment What is the Atmosphere made from Composition It has TWO permanent gases Oxygen 21 and Nitrogen 78 Nitrogen Added by volcanic eruptions plants burning of fossil fuels decay and burning organic material Plants give us nitrogen which they get from nitrogen fixing bacteria What happens if you get too much nitrogen Cancer disease reproductive issues and more Oxygen Added by plants We inhale oxygen and exhale CO2 Argon another but less significant permanent gas 0 934 We use argon in between panes of glass to insulate and use it for cooling Permanent meaning it is constant throughout the atmosphere All other gases are a Trace water vapor carbon dioxide and ozone More permanent gasses Neon helium krypton and hydrogen Variable Gasses Green House Gases Water vapor H2O 0 4 A Amount present determines humidity and how much moisture you have available for rain B Varies by geographic location C Has significant effect on weather and climate Carbon dioxide CO2 A B C D Found uniformly in lower levels of atmosphere Has significant impact on weather and climate Can absorb IR radiation Helps warm the lower atmosphere Increasing levels causing global climate change Carbon Monoxide CO Trace A Forms by photochemical reactions in atmosphere B Also by volcanoes forest fires burning fossil fuels coal auto concentrations C Toxic to humans in high concentrations Methane CH4 000178 A Natural emission of methane gas include bacteria wetlands bogs plants animals B Anthropogenic emissions include feedlots agriculture landfills waste treatment Landfills are piled up covered in soil sometimes snow and are used in recreation or for further development Ozone O3 A Minor but important B Composed of 3 oxygen molecules C Found in ozone layer between 15 48 km above the earth D Absorbs UV light and filters these rays to protect life E Breakdown of ozone layer with CFC s has created a hole and increased UV light on earth they thought CFC s were safe when Freon travels up to the ozone it breaks it apart creating free radicals allowing too much UV to hit the earth causing disease cancer etc F Montreal protocol international treaty to help slow it down Sulfur Dioxide SO2 A Poisonous gas B Released by volcanic eruptions industrial processes oil and coal combustion C Responsible for acid rain Nitrogen Dioxide NO2 A Reddish brown toxic dust B Prominent air pollutant Atmospheric Particulates Aerosols 1 Non gaseous particles which exist in the atmosphere 2 Largest are liquid water and ice form clouds 3 Dust large enough to be seen 4 Human induced and natural types volcanic ash windblown soil meteor debris smoke salt spray pollution it is needed for rain to fall Vertical Structure Pressure Composition of the Atmosphere Five Major Thermal Layers 1 Troposphere decreasing temp lowest 10 15km of atmosphere most weather occurs here 2 Stratosphere Increasing 18 50 km stagnant air The ozone layer is here holding in energy 3 Mesosphere Decreasing 52 80 km No more ozone and it cools down 4 Thermosphere Increasing 100 225 km 5 Exosphere Increasing 225 km transitions into interplanetary space All affect thermodynamic energy on the planet The top of each of the three layers transition zones is called the Tropopause Stratopause and Mesopause Atmospheric Pressure Air Pressure Air pressure is greatest at sea level Air pressure impacts things as simple as baking cookies Refers to the weight of overlying air measured with a barometer The taller the column of air above an object the greater the air pressure Because air is highly compressible the lower levels of air are compressed by those above thus increased pressure and higher density air in lower levels of atmosphere Pressure is it s highest at sea level Atmospheric Pressure decreases rapidly with increasing Altitude