Dear cybergeographers, Here's a study guide of terms and concepts to make sure you know before the second exam. If you peek at this first, you'll find it overwhelming. If you have done all your reading first, though, this will make a lot of sense and help jog your memory. Dr. R ----- Lecture 13: Gaseous composition of the atmosphere Molecular nitrogen percentage of dry air by volume stable Molecular oxygen percentage of dry air by volume oxidation Trace gasses carbon dioxide percentage of dry air by volume trends in that amount over last 100 years which human activities are increasing it complicating factors carbonic acid formation increased photosynthesis climate cycles greenhouse gas and thermostat function balance of scientific opinion on effect of CO2 ozone role of ozone in stratosphere UV trapping warming of stratosphere ozone hole causes: chlorinated fluorocarbons (CFCs) and other chemicals possible consequences how you might protect yourself a bit other powerful greenhouse gasses on the increase methane nitrous oxide CFCs Lecture 14: Dust and water in the atmosphere Solids in the atmosphere dust or "particulates" sources condensation nuclei humans increase dustiness effects on climate of increased dustiness Water exists in all three states of ordinary matter: solid, liquid, gas constantly changing state latent heat of evaporation water's role in temperature regulation Lecture 15: Vertical pressure structure of the atmosphere Sea level air pressure in kg/sq. cm. Rate of fall off in air pressure with altitude Gay-Lussac Law Why humid air is less dense than dry air at same temp. Torricelli's experiment back in 1643 main point modern instrument based on it average height of mercury column at sea level Boiling point of water as it's affected by air pressure Boyle's Gas Law Lecture 16: Vertical temperature structure of the atmosphere The difference between direct and inverse relationships Tropopause inverse relationship between altitude and temperature normal lapse rate mixing by storms, convection, and wind height Stratosphere direct relationship between altitude and temperature role of ozone layer in creating the stratosphere height Mesosphere resumption of inverse relation of altitude and temp. much quieter than the troposphere height Thermosphere direct relationship between altitude and temperature why 1,000 degrees C aren't as impressive there height ionosphere why ions are created there how ions are affected by earth's magnetic field aurorae (aurora borealis and aurora australis) why aurorae are mostly high latitude experiences effect of ionosphere on radio wave propagation Isothermic belts tropopause stratopause mesopause Lecture 17: Temperature as an element of weather Weather versus climate Four basic elements of weather Earth's radiation balance Electromagnetic spectrum and where's sun's radiation fits ultraviolet short wave visible light is where sun's output peaks infrared long wave Kelvins Wien's Displacement Law average temperature of sun's surface average temperature of earth's surface Insolation Solar constant Zenith Relation between sun's angle with zenith and intensity What affects sun's angle with zenith and intensity latitude time of year time of day Albedo Bond albedo percentage of insolation that is reflected (albedo) parties responsible for albedo dust and gas molecules clouds earth surfaces Absorption what absorption means percentage of insolation that is absorbed parties responsible for absorption Specific heat land has low specific heat water has high specific heat Atmospheric windows Heat transfers: direct (can take place in still air) conduction radiation how these two are connected with normal lapse rate how these two are connected with inversions indirect (require vertical movement of air) dry adiabatic process Boyle's Gas Law: rising air=less pressure=expansion sinking air=more pressure=compression Amonton's Gas Law: expanding gas cools compressing gas warms applies to rising or sinking dry air creates a larger lapse rate: dry adiabatic lapse rate adiabatically heated winds like our Santa Anas wet adiabatic process ONLY applies to RISING, COOLING air colder air can hold less water vapor saturation dew point lifting condensation level (dew point elevation) cooling past saturation=condensation/freezing condensing/freezing vapor releases latent heat this slows cooling to a smaller rate wet adiabatic lapse rate why air is warmer on leeward side of mountains Lecture 18: Pressure as an element of weather What is air pressure? How it's measured: Directly as weight Indirectly as height of column of mercury in barometer Directly as force exerted: 1 hPa=1 mb Average air pressure at sea level How air temperatures affect pressure Cyclones and anticyclones Mapping air pressure variations isoline maps isobars conventional isobar interval Advection Coriolis Effect Ferrel's Law of Coriolis Effect Forces working on a wind once it starts moving pressure gradient definition effect on wind speed Coriolis Effect intensifies with speed of air flow intensifies with higher latitude friction reduces speed of air flow near earth's surface weakens Coriolis Effect Directions winds spiral Northern Hemisphere clockwise out of a high counterclockwise into a low Southern Hemisphere counterclockwise out of a high clockwise into a low Horizontal winds named for direction FROM which they blow Pressure and wind systems Global scale analysis and synthesis and simplifying assumptions pressure belts: 0 degrees: equatorial low Doldrums Inter-Tropical Convergence Zone (ITCZ) 30 degrees N or S: subtropical high Horse Latitudes 60 degrees N or S: subpolar low 90 degrees N or S: polar high winds: Trade Winds: from subtropical high to ITCZ slight easterly bias due to Coriolis Effect Prevailing Westerlies: from subtropical high to subpolar low marked westerly bias due to Coriolis Effect Polar Easterlies: from polar high to subpolar low extreme easterly bias due to Coriolis Effect global pressure and wind system's causes convection distorted by Coriolis Effect axial tilt and seasons shifts bands north and south land and sea have different specific heat Summer heating of land around 30-40 degrees N breaks up and concentrates subtropical high two intense oceanic peaks (names?) strengthened effect on weather west coasts dry: winds and cold currents east coasts humid: winds and warm currents Summer heating of land around 40-70 degrees N allows subpolar low to extend across land this smears it: a shallow low pressure belt smearing weakens it: fewer storms Winter chilling of land around 30-40 degrees N allows subtropical high to connect over land this smears it into a lower ridge smearing weakens it, letting storms in Winter chilling of land around 40-70 degrees N breaks up and concentrates subpolar low two intense oceanic pits (names) strengthened effect on weather: many storms west coasts less cold: tepid ocean currents east coasts very cold: continentality Continent-scale wind and pressure systems called monsoons seasonally-reversing summer monsoon moves onshore heated land creates low cooler oceans create high winter monsoon moves offshore cold land creates high warmer oceans create low Local scale wind and pressure systems diurnally reversing land and sea breeze summer daytime airflow onshore (sea breeze) land heats, resulting in low water still cool, resulting in high night-time airflow offshore (land breeze) land chills, resulting in high water still warm, resulting in low upslope/downslope breeze night-time inversion layer forms chilled air on hillsides sinks this creates a downslope breeze daytime breakup of inversion warmed air rises hill peaks warm first (inversion thinnest) lows form above peaks, drawing airflow upslope breeze results Lecture 19: Moisture as an element of weather What is humidity? Measurement: specific and absolute humidity saturation vapor pressure or saturation quantity saturation dew point can you read saturation quantity from temperature on chart? relative humidity formula sling psychrometer dry bulb temperature (DBT) wet bulb temperature (WBT) why does wet bulb temperature drop? wet bulb depression (WBD) can you read relative humidity from DBT and WBD? Manifestations of humidity dew frost fog (radiation versus advection) clouds similarities and differences with fogs cloud classification by altitude, shape, activity cirrus, cirro-stratus, cirro-cumulus alto-stratus, alto-cumulus stratus, nimbo-stratus, strato-cumulus cumulus, small cumulus, enlarged cumulus cumulo-nimbus precipitation rain snow sleet hail what's the difference between sleet and hail? causes of precipitation (how air chills enough) orographic convectional convergent frontal Lecture 20: Storms as an element of weather Bjerknes' Air Mass Analysis air masses definitions source regions fronts cold fronts fast moving cumuliform clouds along front (cumulo-nimbus, cumulus) sometimes tornadoes in front of cold fronts warm fronts slow moving stratiform clouds that lower as front approaches (cirrus, cirro-stratus, alto-stratus, stratus, nimbo-stratus) wide band of clouds/precip in front of front occluded fronts cold front catches up with warm front all warm air hoisted up, intensifying precipitation briefly warm air shot aloft cools and front dissipates Storm types mid-latitude travelling cyclones mid-latitude wave cyclones ordinary mid-latitude winter storm four stages of development pulled along by subpolar jet stream eastbound Rossby Waves index cycle: low index equals extreme bends high index equals straighter track jet stream/storm tracks tornadoes funnel cloud formation characteristics and sources of damage does California get them? Fujita Scale why are they more New World phenomena? tropical disturbances easterly waves most common tropical disturbance what causes them? what are they like? (who gets rained on when?) tropical cyclones aka hurricanes and typhoons definition and characteristics the eye wind reversal what's the dangerous side and why? what causes them to die out? which part of the ocean oddly doesn't get them? (URL 7) sources of hazard Saffir-Simpson Scale polar outbreaks what they're like why they're more New World phenomena weak equatorial lows very localized associated with ITCZ instability what they're like why don't you get hurricanes on the equator? high latitude storms least understood storm types polar lows are analogous to mid-latitude wave cycl. polar hurricanes ("The Perfect Storm") similarities to true hurricanes differences Importance of storms determine precipitation and fresh water distribution move energy from tropics to high latitudes generate all kinds of hazards Lecture 21: Climates For each major climate type: know what they're like in temperatures, precipitation, seasonality where you find them and why Tropical humid climates tropical rainforest climates tropical monsoon climates tropical wet-dry (or savanna) climates Dry climates tropical (hot or low) desert temperate (mid-latitude or high) desert tropical semi-arid (or steppe) temperate semi-arid (or steppe) Temperate humid climates Humid subtropical climates West coast marine climates Mediterranean climates (California's) Temperate wet-dry climates Humid continental climates Humid all year continental Humid continental dry in winter Highland Mediterranean (humid contin. dry in summer) Extremely cold climates Tundra climates Ice cap climates Antarctican & Greenland glaciers, some alpine ones Pleistocene ice sheets covered ~1/3 of land surface Highland climates Microclimatic variation Lapse rates up a mountain make it colder up there Aspect Adret and ubac aspects Windward and leeward aspects Lecture 22: Climate change Human role in changing climate Greenhouse gasses Average global temperatures have climbed half degree Climb co-incides with Industrial Revolution Non human-induced long-term climate changes Late Proterozoic glaciations and volcanoes Carboniferous/Permian glaciations and role of plants Pleistocene glaciations Post-Pleistocene climate change Climatic Optimum Little Ice Age Causes of secular climate changes Milankovitch factors variation in tilt of axis over ~41,000 years precession of equinoces over ~22,000 year cycles changes in earth orbital eccentricity: 100,000 yrs Volcanic eruptions Carbon dioxide emissions and Proterozoic ice age Dust and sulphur dioxide and cooling Changes in solar "constant" Glaciation becoming a self-sustaining runaway process End of the Little Ice Age vs. human greenhouse emissions What is the majority consensus among scientists? What are some consequences of global warming? How might California be affected? Textbook: Pidwirny provides his own study guide at the end of Ch. 6, 7, & 8 03/13/08