Meteorology: The study of the Air and the Atmosphere. Text: Module 2 pages Reading Assignments Module 13 pages 25-50

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1 Meteorology: The study of the Air and the Atmosphere Text: Module 2 pages Reading Assignments Module 13 pages Homework Assignment Module 13 Study Guide Questions p # 1-20 Introduction (p 25) Meteorology: The next will come from the science of meteorology. Meteorology is the study of the atmosphere and the atmosphere is made up of air. So we will start study the air. The Air and Humidity (p 25) Humidity: The gas moisture content of the air (water vapor) o vapor is a gas that can change state at normal temperature (it is invisible) What to measure humidity (p 27) oabsolute humidity: mass of water vapor per unit volume (g/l or g/m3) omixing Ratio: mass of water vapor per mass of dry air ospecific Humidity: mass of water vapor per mass of real (moist) air odew point: Temperature at which condensation will occur for a give parcel (piece of air) Can be used to indicate the humidity. All of the above are good at indication how much water vapor is actually in the air and how we feel. orelative Humidity: RH is the % ratio of mass of water vapor in the air as compared to how much it could hold at a given temperature. RH is NOT a good indicator of how we feel because it does not tell us ANYTHING about the moisture content of the air without the temperature. It is a good during indicator. Experiment 2.1 Evaporation and Temperature (p 25) The Composition of Air (p 28) (1) The "Constant" or "dry air" gases Nitrogen (N 2 ) % Oxygen (O 2 ) % Argon (Ar) -.9 % CO % Other SO2, NO2 - ~0.07% (2) Concept of Concentration

2 Part per Million. Billion (PPM, PPB etc) Mixing ratio mass:mass Density m/volume Percent (relative concentration) what if O 2 were mire concentrated: Few more percent more fires high O 2 (over 60%) actually dangerous to breath. Fire: Fuel + O 2 = CO 2 + water (burning or combustion) - oxidation Exothermic reaction CH 4 + 2O 2 CO 2 + 2H 2 O 2H 2 + O 2 2H 2 O + heat Few less percent we could breath effectively The importance of Nitrogen (N 2 ) as dilution: most others would be toxic and CO2, Argon are strong greenhouse gases. (3) Water Vapor the Principle Variable gas Much of what we call weather is some form of water (H 2 0). The most import gas in influencing the weather is water vapor. It is the main ingredient of clouds, precipitation. form clouds Water Vapor (H 2 0 gas) ranges from % of the total atmosphere Only major substance that change state in the atmosphere causes "Latent heating and cooling". MOST important Greenhouse Gas Plays a major role in the global heat (energy) transport (3) Other Important Gases Carbon Dioxide (CO 2 ) - Important greenhouse gas, it is increasing in the atmosphere. Ozone (O 3 ) - Stratospheric O3 Protects us form UV light Experiment 2.2: Oxygen and Fire (p 30) Carbon Dioxide in the Air (p 32) Important as a greenhouse gas: helps keep planet warmer a good thing in moderation Also important for Plants (plant breath CO 2 give off O 2 )

3 Animals breath O 2 give of CO 2 Look at Figure 2.5 page 35 Greenhouse Effect: Trapping heat through a radiation process See Figure 2.4 Page 33 Go over how much more important Water Vapor is in terms of CO2 10 time moire effective 100 time more abundant 3% as compared to.03 %. Methane (natural gas) source decomposition, animals gas Why greenhouse is not a good process analogy as to how this effect works. Experiment 2.3: Carbon Dioxide and the Greenhouse Effect Global Warming (p 36) Global warming refers to the increase in the average temperature of the Earth's nearsurface air and oceans in recent decades and its projected continuation. The cause of GW proposed by some is increased CO 2 by man's burning of fossil fuels. See figure 2.6 page 37 talk about the breathing of earth in it CO 2 record. Climate versus Weather You can observe and feel weather You can calculate climate from observations statistics like average temperature, extremes etc. Global versus regional climate change Trends in climate climate an length of time Natural versus human induced climate change Man can clearly influence the local climate cities, cutting fields Disaster versus change Is there global warming on the long term see bottom of chat figure 2.6 page 37 and fig 2.7 page 40 and discuss most recent trend. Discuss the use of figures to make one's point. Parts Per Million Ozone (p42) Number of atmos or molecules per million of the entire mixture Converting ppm to % 1% = 10,000 ppm Convrt 290 ppm to percent page 41. Ozone O3 very reactive Reacte with UV light to breack deon to O2 and O an O recombine ot form O2 and O3 in a never ending cle Ozone layer in the stratosphere. This layer absorbs 97-99% of the sun's high frequency ultraviolet light which is potentially damaging to life on Earth.

4 Air Pollution (p 44) Over 90% of ozone in earth's atmosphere is present here. "Relatively high" means a few parts per million much higher than the concentrations in the lower atmosphere but still small compared to the main components of the atmosphere. It is mainly located in the lower portion of the stratosphere from approximately 15 km to 35 km above Earth's surface, though the thickness varies seasonally and geographically. See figure 2.8 page 43 go over and diagram the process. Air pollution is a chemical, particulate matter, or biological agent that negatively (in term of human health) modifies the natural characteristics of the atmosphere. Toxic versus non toxic pollutants Types of pollutants: Sulfur oxides (SO x ) especially sulfur dioxide are emitted from burning of coal and oil. Natural source is volcanoes. Scrubbers can remove form smoke stacks Nitrogen oxides (NO x ) especially nitrogen dioxide are emitted from high temperature combustion. Can be seen as the brown haze dome above or plume downwind of cities. Automobiles, planes main source of NOXs. Ground Level Ozone: (O 3 ) formed from NOx and VOCs Carbon monoxide is colorless, odorless, non-irritating but very poisonous gas. It is a product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide. Carbon dioxide (CO 2 ), a greenhouse gas emitted from combustion and respiration. Volatile organic compounds (VOC), such as hydrocarbon fuel vapors and solvents. Chlorofluorocarbons (CFCs), harmful to the ozone layer emitted from products currently banned from use. Airborne Lead negative effect brain development. See figure 2.9 (page 47) The Atmosphere Text: Module 3 pages Reading Assignments Module 3 pages Due Apr 11 Homework Assignment Module 3 Study Guide Questions p # 1-17 Due Apr 11 Introduction (p 55)

5 The discussion of the composition of the air has now set the stage for us to learn about the atmosphere as a whole. Atmosphere: the mass of air that surround the earth. How thick is the atmosphere. Show that if the earth were the size of a globe (basketball, the atmosphere is the about.4 ). Diameter of Earth: 8000 miles = 8000 x 5280 ft = 42,240,000 ft Diameter of a basket ball: about 1 foot. Top of atmosphere (80%) is about 40,000 feet. Relative Thickness of atmosphere for a basketball sized earth would be: 40,000 feet/42,240,000 feet =? feet/1 feet? feet = 40,000 feet/42,240,000 feet =.0009 feet =.01 inches Diameter of Earth: 8000 miles = 8000 x 5280 ft = 42,240,000 ft Diameter of a basket ball: about 1 foot. Top of atmosphere (99%) is 26 miles or about 137,280 feet. Relative Thickness of atmosphere for a basketball sized earth would be: 137,280 feet/42,240,000 feet =? feet/1 feet? feet = 137,280 feet/42,240,000 feet =.03 feet =.4 inches Atmospheric Pressure (p55) Pressure exerted by the atmosphere on all object within it. In simple terms it is the measure of the concentration of weight of the air. Atmospheric pressure is the pressure at any point in the Earth's atmosphere. In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. Low pressure areas have less atmospheric mass above their location, whereas high pressure areas have more atmospheric mass above their location. Similarly, as elevation increases there is less overlying atmospheric mass, so that pressure decreases with increasing elevation. A column of air 1 square inch in cross section, measured from sea level to the top of the atmosphere, would weigh approximately 14.7 lbf. A 1 m² (11 sq ft) column of air would weigh about 100 kilonewtons (equivalent to a mass of 10.2 tons at the surface). Can experiment - Look at figure 3.1 and talk about the film. Barometer - instrument to used to measure atmospheric pressure. Types: Water, mercurial (see figure 3.2 p 59), aneroid: Units: inches of Hg, mmhg, millbars, pascals, atm. Types of Pressure Measurements: Barometric pressure: The pressure as measure by a barometer. Station Pressure: The barometric pressure at a given surface station. Mean sea level pressure (MSLP) is the pressure at sea level or (when measured at a given elevation on land) the station pressure reduced to sea level assuming an isothermal layer at the

6 station temperature.this is the pressure normally given in weather reports on radio, television, and newspapers or on the Internet. When barometers in the home are set to match the local weather reports, they measure pressure reduced to sea level, not the actual local atmospheric pressure. See Altimeter (barometer vs. absolute).the reduction to sea level means that the normal range of fluctuations in pressure is the same for everyone. The pressures which are considered high pressure or low pressure do not depend on geographical location. This makes isobars on a weather map meaningful and useful tools. Altimeter setting in aviation,, is another atmospheric pressure reduced to sea level, but the method of making this reduction differs slightly. Experiment 3.1: Atmospheric Pressure (p 56) The Layers of Earth s Atmosphere (p 60) Chemical compositions: Homosphere (p 62) same composition with altitude to about 80 km (50 miles) 78 % N2, 21% O2 1 % other. Herterosphere: different composition with altitude above 80 km (50 miles) See figure 3.3 page 61. Electrical Nature: Neutral and charge (ionosphere) Thermal: What is Temperature (p 66) Temperature is th average KE of the molecules of any substance. Measures on average how fast t they are moving. Heat is the measure of the total energy in a subsistence. Heat always flows from hot to cold. How can an astronaut freeze if the temperature is 10,000 degrees. Experiment 3.2 Seeing the Effect of Changing Temperature (p 66) Important Thermal Structure Terms (Note the unusual use of the term gradient which is typically horizontal that should be more traditionally called the lapse rate. ) Lapse Rate: The lapse rate is the rate of change of temperature with height A positive lapse rate cools with height A negative lapse rate warms with height Inversion: If the temperature increases with height (a negative lapse rate) it is called an inversion. That means it is "inverted" from the normal situation in the troposphere of cooling warming with height. Thus a negative laps rate indicates an inversion.

7 "Pauses": The suffix "pause" is give to the top of any given layer. So a pause is the transition level from one layer of the atmosphere to another (e.g. tropopause). The Temperature Gradient in the Homosphere (p 69) Decreases in the lower, then increases then decreases again than in heterosphere it increase one more time. Thermal Layers Five Thermal Layers (See homospere figure 3.5 page 65) Troposphere "weather layer": Surface to 10 km Cools with height Heat source ground or ocean surface Stratosphere Passenger Jet Flight Level : km Warms with height Heat Source O3 layer Reactions with UV Light Mesosphere Cold Layer: km Cools with height Heat Source Top of Stratosphere Thermosphere - Warm layer: km Warms with height Heat Source O2 Reactions (dissociation) with UV Light Exosphere - Very sparse outer most region of the atmosphere: Above 100 km (not always considered a thermal layer) Jet steams: Large concentration of high winds as stream of air top of troposphere. Make a diagram. The Hole in the Ozone Layer (P 69) Ozone depletion describes 14 distinct, but related observations: a slow, steady decline of about 4 percent per decade in the total amount of ozone in Earth's stratosphere since around 1980; and a much larger, but seasonal, decrease in stratospheric ozone over Earth's polar regions during the same period. The latter phenomenon is commonly referred to as the ozone hole. In addition to this well-known stratospheric ozone depletion, there are also tropospheric ozone depletion events, which occur near the surface in polar regions during spring. The detailed mechanism by which the polar ozone holes form is different from that for the mid-latitude thinning, but the most important process in both trends is catalytic destruction

8 of ozone by atomic chlorine and bromine. The main source of these halogen atoms in the stratosphere is photodissociation of chlorofluorocarbon (CFC) compounds, commonly called freons, and of bromofluorocarbon compounds known as halons. These compounds are transported into the stratosphere after being emitted at the surface. Both ozone depletion mechanisms strengthened as emissions of CFCs and halons increased. Diagram of the Ozone CFC process O3 + uv => O2 +O => O2 +O + uv = O3 O3 + uv => O2 +O CFC + uv = CF + Cl => Cl + O => ClO doesn t stop uv no O to make O3 Location and time of year of Ozone depletion: Role of the polar vortex special meteorology How long have we observed it since 1950 s See figure 3.6 p 70. Reduction in CFC - hol;e is slowly improving. The Hydrosphere (p 73) Thermosphere km location of the ionosphere. Exosphere above 460 km. Week 30: Apr 21 - Apr 26 Factors that Effect The Weather Text: Module 7 pages Reading Assignments Week 30: Module 7 pages Due Apr 25 Homework Assignment Week 30: Module 7 Study Guide Questions p # 1-17 Due Apr 25 Week 30 Quiz Fri Apr 26 Monday and Thursday Lecture Topics Apr 7 and 11 Introduction (p 157) Factors that Influence the Weather (p 157) Clouds (p 157) Experiment 7.1: Long Term Weather Experiment (p160)

9 Earth s Thermal Energy (p 161) Latitude and Longitude (P 165) Uneven Thermal Energy Distribution (p 166) Scales of weather moving and non movingfactors. General Circulation Regional Influences Local sclal Air Masses (p 172) Concept of Fronts Week 31: Apr 28 - May 2 Factors that Effect The Weather Text: Module 8 pages Reading Assignments Week 31: Module 7 pages Due May 1 Homework Assignment Week 31: Module 7 Study Guide Questions p # 1-17 Due May 1 Week 31 Quiz Fri May 2 Monday and Thursday Lecture Topics Apr 7 and 11 Introduction (p 181) Precipitation (p181) Mid latitude cyclone Relationship to fronts and the Jet stream How precipitation forms: cold and warm rain process Water cycle Special Frontal Weather Showers Thunderstorms (p 181) Derechoes Tornadoes (p190)

10 Tropical Weather and Tropical Storms Hurricanes (p 190) Weather Maps and Prediction (194) From Exp 7.1Making your own wether Predictions: 198 Exp 8.2 Turning Exp 7.1 in a Weather prediction tool. P 199