Updated Geography Study Guide for Exam 1
Updated Geography Study Guide for Exam 1 GEOG 1112
Popular in Intro to Weather and Climate
verified elite notetaker
Popular in Geography
This 15 page Study Guide was uploaded by Kaley Notetaker on Tuesday September 20, 2016. The Study Guide belongs to GEOG 1112 at University of Georgia taught by Dr. Elgene Box in Fall 2016. Since its upload, it has received 16 views. For similar materials see Intro to Weather and Climate in Geography at University of Georgia.
Reviews for Updated Geography Study Guide for Exam 1
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 09/20/16
Geography Study Guide for Hour Exam #1: 1. Components of the Atmosphere: Nitrogen: 78% (passive; some exchange via bacterial fixation) Oxygen: 21% (quite reactive; oxidation (burning, rusting, etc.) and respiration) Argon: 1% (inert gas; no reactions with anything under natural conditions) Carbon Dioxide: 400ppm (biological metabolism, decomposition, burning etc.) Atmospheric Pressure: weight of the air column above a place, measured is millibars of equivalents (1000 mbar = 1 kg air/cm^2 surface area - Average Atmospheric pressure is at sea level and is 1013 mbar (roughly equivalent to 30 inches of mercury if measured by a barometer) *1013 mbar = 1 std. atm. - Atmospheric pressure decreases upward since the higher you go up, the less air there is to press down on the surface. Atmospheric pressure drops by half by about 18,000 ft. high - Millibar: unit of atmospheric pressure; (mb) Hydrostatic Equilibrium – when upward pressure gradient force is balanced by downward force of gravity; this is the reason why Earth does not lose it’s atmosphere Temperature: measurement of kinetic energy of the molecules comprising a substance Temperature Cycle: Temperature Range: Isotherm: Line seen on a weather map that connects points of equal temperature; no change in temperature while following along an isotherm - Isotherms sit perpendicular to temperature gradients - Temperature Gradient: temperature change per unit distance. The stronger the gradient, the more rapidly the temperature changed over a short distance Troposphere: lowest 15 km (9 mi) of the atmosphere where nearly all weather events occur and most water vapor is found; temp decreases with increasing altitude Stratosphere – 15-50 km (9 – 31mi). initially steady temperatures with altitude, then increasing toward the upper stratosphere. This is where the ozone layer is located Mesosphere – 50-80km (31-50mi) Decreasing temperature with altitude. Basically no meteorological significance Thermosphere – 80+ km (above 50 mi), no definite top; increasing temperature with altitude but very low density Atmosphere-Ocean Interactions: 2. Sensible Heat: energy contained in air that is measured with a thermometer (aka: temperature); the amount of internal molecular energy per unit of volume; transferred via conduction (slow process) or convection (only in fluids) - Conduction: when heat moves through a substance without notable movement of the molecules o ex: Heating a metal pot over an open fire will begin by the bottom of the pot being warmed, but eventually the entire pot and even the handle will become warm too - Convection: heat transfer via mixing of a fluid; most have movement of the liquid or gas to be completed o Ex: a pot of water boiling – the water at the bottom boils first because it is closest to the heat, then the rest of the water gradually warms up also o Both sensible heat and latent heat can be moved by convection Change of state: involves latent heat - Done through melting (solid to liquid), evaporating (liquid to gas), condensating (gas to liquid) and freezing (liquid to solid) - Melting and Evaporating REQUIRE energy input in order to break the pre-existing molecular bonds (if energy comes from surrounding environment, it is cooled by energy loss = evaporative cooling) - Condensation and Freezing RELEASE energy as bonds are re- established; energy release warms the surroundings = condensational warming Evaporative Cooling: reduction of temperature of a substance because evaporation has taken place; evaporation removes latent heat from the surface, thus causing the temperature of that liquid to decrease Latent Heat – Energy present in water vapor, used in converting water from liquid to gas; released during condensation; energy associated with the change of phase of a substance 4 Laws of Radiation 1. Everything radiates 2. Hotter objects (aka objects with more internal energy) radiate more 3. Waves carrying more energy have higher frequencies, so they vibrate faster 4. All objects radiate over a range of wavelengths; the wavelength of the GREATEST emission is given by Wein’s Law Wein’s Law tells us that objects at differing temperatures emit different wavelengths. Peak wavelength (which is inversely related to temperature!) can be found with this formula: = (2897 / T) µ T = Surface Temperature (in Kelvins) ; answer is given with in measurements of µ Laws of Wave Motion: P. 38-41 in textbook Wavelength: Distance noted between 2 peaks of a wave or 2 successive troughs on a wavetrain - Amplitude is distance from middle line to top of wave or bottom of trough (see p. 21 in workbook) Energy Flux: top of p.22 in workbook 3. p.22 in workbook; Energy Balance – Energy gains = energy losses; temperature is unchanging R = H + G + LE + F + Ph - R = net radiation; resultant sum of all radiation processes K and L (positive input of energy during the day, net loss at night) - H and G = Sensible heat conducted upward (H) or downward (G) during the day, following the law that heat moves from warmer to cooler places - LE = latent heat (energy) released by evaporation of water ad transported upward by convection (generally zero at night) - F = net energy gain or loss by advection (aka horizontal energy transfer; aka wind) - PH = energy fixed into the biomass by photosynthese - Be sure to factor in cooler soil, water in landscape, nighttime, and “wet” versus “dry” environments; p. 24 in notebook Earth Radiation: controls cloudiness water vapor in air, effective sky temperature and pollution Net radiation – difference between absorbed and emitted radiation; includes both solar and terrestrial radiation Conduction: when heat moves through a substance without notable movement of the molecules o ex: Heating a metal pot over an open fire will begin by the bottom of the pot being warmed, but eventually the entire pot and even the handle will become warm too Convection: heat transfer via mixing of a fluid; most have movement of the liquid or gas to be completed o Ex: a pot of water boiling – the water at the bottom boils first because it is closest to the heat, then the rest of the water gradually warms up also o Both sensible heat and latent heat can be moved by convection Shortwave (solar) radiation: visible light; controls latitude, time of year, time of day, elevation and cloudiness (p.22) - Shorter wavelengths correspond to higher energies Temperature Controls: Latitude Altitude Land Vs. Water Currents Geographic Position Environmental Lapse Rate (ELR): rate of vertical temperature decrease in the air column; varies based on local conditions; cooling rate upward in troposphere (p,145 in textbook) Global avg. for troposphere = 0.65°C/100 m Factors that can influence ELR: 1. Surface heating --- surface air warmed and may rise 2. Surface cooling --- surface air cooled, will not rise 3. Advection of warmer air --- new air may be warmed than air above and thus could rise 4. Advection of cooler air --- new air may destroy existing instability 5. Radiative cooling of cloud tops --- creates larger ELR and can cause instability indirectly Temperature Profile above the surface: Day vs. night (controlling factors) Three processes affect the distribution of temperature throughout the atmosphere: 1. Absorption 2. Scattering 3. Transmission Daily and Annual Temperature Cycles, controlling factors: 4. Vapor Pressure: a measure of atmospheric moisture, the partial pressure exerted by water vapor Ideal Gas Law: The equation that relates air pressure to temperature and density – PV = nRT (P=pressure of gas, V=Volume of gas, n=amount of substance in gas (measured in moles), R=universal gas constant, T=Absolute temperature of the gas) Pressure gradient – Rate of change of pressure over distance. Gives rise to the pressure gradient forec that sets air in motion Pressure gradient force: Causes air to blow from an area of high pressure toward an area of low pressure. Vertical pressure gradient force is always present but is nearly balanced by gravity most of the time; much weaker horizontal pressure gradients are the ultimate cause of wind Advection: transport of an atmospheric property (heat, moisture, etc.) horizontally; AKA: WIND Because of coriolis effect: Wind appears to blow in arcs (not straight lines) Wind crosses isobars at angles instead of perpendicularly Land breeze – A wind that blows from the land toward the water along the coastal zone during the night and early morning; the result of differential cooling between land and sea; Sea Breeze – flow or air from water toward land along a coastal region Katabatic wind – airflow down a slope under the influence of gravity Santa Ana wind – wind that flows downslope and warms by compression in California Mountain wind – a breeze that flows down hill at night Valley Wind – low-level movement of air in an upslope direction; develops during daylight hours as a result of solar heating Chinook wind – downslope winds that warm because of adiabatic compression Thermal low – low-pressure cell produced by heating of the surface Upper-air gradients Coriolis Force: An imaginiary deflective force arising from Earth’s rotation that is necessary to account for motions measured relative to the surface - Apparent deflection of motion in fluids resulting from Earth’s rotation o 1. Coriolis deflection is zero at the equator and INCREASES towards the poles o 2. Coriolis deflects to the RIGHT in the N. Hemisphere and to the LEFT in the S. Hemisphere o As a result, Wind appears to blow in arcs (not straight lines) Wind crosses isobars at angles instead of perpendicularly Friction: Force that acts to slow wind but does not change its direction. Friction develops between the atmosphere and surface and between layers of air moving at different velocities Upper-atmosphere winds Near Surface winds: Cyclone – A region of low pressure relative to the surrounding area Anticyclone – areas of high pressure Sky Conditions – [8.] Land breeze – A wind that blows from the land toward the water along the coastal zone during the night and early morning; the result of differential cooling between land and sea; Sea Breeze – flow or air from water toward land along a coastal region Katabatic wind – airflow down a slope under the influence of gravity Santa Ana wind – wind that flows downslope and warms by compression in California Mountain wind – a breeze that flows down hill at night Valley Wind – low-level movement of air in an upslope direction; develops during daylight hours as a result of solar heating Chinook wind – downslope winds that warm because of adiabatic compression Thermal low – low-pressure cell produced by heating of the surface Monsoon system: A monsoon is a regional circulation pattern in which there is a seasonal reversal of wind and pressure, generally characterized by onshore flow during the summer and offshore flow during the winter Global atmospheric circulation: Pressure belts, prevailing winds, sky conditions 5. Vapor Pressure: a measure of atmospheric moisture, the partial pressure exerted by water vapor Saturation – the maximum amount of water than can exist in the atmosphere as a -- vapor. resulting equilibrium state of air after evaporation and condensation (opposing processes) have offset gains and losses - As long as the rate of evaporation exceeds the rate of condensation, the amount of water vapor increases. - When condensation rate = evaporation rate, saturation occurs Evaporation – change in phase of liquid water to water vapor - Mainly a function of 2 factors: o 1. Energy input, needed to change the state from liquid to gas comes mainly from sunshine o 2. Adjacent “dry” unsaturated air, which takes up more water described by the saturation deficit Evaporation is closely proportional to saturation deficit o Wind also increases evaporation by removing the saturated air and bringing in dry air Condensation: change from vapor to liquid phase; releases energy required for evaporation Condensation level – level at which water vapor condenses onto dust particles, ice crystals, particulate pollution, airborne bacteria, or other condensational nuclei Saturation deficit – the amount of water that air, under given conditions, can still absorb before becoming saturated - Saturadtion deficit = SVC – VC - SVC- potential water content - VC – actual water content - Measure in grams of water per kg of air (same from VC ans SVC) Relative humidity – measure of amount of water vapor in the air as a fraction of saturation; expressed as a percentage; relative humidity depends on both the moisture content and the temperature of the air - RH = VC / SVC (x100 for percent) - VC – actual water content under the current conditions - SVC – amount of water air CAN hold at the curret temperature - Warming REDUCES r.h., cooling INCREASES r.h. “Doubling Rule” : refers to the phenomenon that happens when temperature (measured in Celsius) increases by 10 degrees, relative humidity doubles. (p.36) - Ex: 20C – 30% r.h. ……… 10C – 60% r.h. …….. 0C – 120% r.h. Dew point : Temperature air must be cooled to in order to become saturated; AKA when relative humidity is 100% Supercooled water – water existing in the liquid phase with a temperature less than 0C Adiabatic Process – term for a process in which no heat is added or removed, but temperature still changes; ex: rising air parcel cools adiabatically as it expands Diabatic process – process where energy is added or removed from a system Dry adiabatic lapse rate - Rate at which a rising parcel of unsaturated air cools and sinking parcel of unsaturated air warms - 9.8C per 1000m / approx. 1C per 100m - Remember* Adiabatic means there is no net loss or gain of energy! Wet adiabatic lapse rate – not a constant, but is normally less than 10 Forms of Condensation: Dew: Condensation deposited on a surface (grass, windshield, etc.) Frost: Coating of ice crytals on a surface when the air adjacent to the surface becomes saturated at temperatures below 0C. Fog: Air that is adjacent to the surface and contains suspended water droplets, usually formed by adiabatic cooling Evaporation Fog: water vapor near warmer (Wet) surface rises and then immediately condenses above; this fog is usually found over a body of water Advection fog - result of either warm or cold advection (warm more common) Advection refers to horizontal movement of air o As air passes over the cooler surface, heat is transferred downward o Can also form over water when warm and cold ocean currents are in close proximity to one another o Common during summer months in San Francisco bay area FORM PROCESS CHARACTERISTICS Dew Lowering of temp to the Coating of liquid on dew point near surface; surfaces often happens under clear skies and no wind. Diabatic Process Frost Lowering of air Large number of small, temperature to white crystals on saturation point (when surface saturation is below 0C). Diabatic Process Frozen Dew Formation of dew at Continuous layer of temperatures above solid ice on surface 0C, followed by cooling of temperatures below 0C; Diabatic Process Fog Usually happens by Large concentration of cooling of layer of air suspended droplets in with light winds; can later of air near ground. happen by mixing warm and cold winds; Adiabatic or Diabatic Process Radiation fog Cooling of air to dew Same as “fog” point by longwave radiation loss. Diabatic process. Advection fog Cooling of air to dew Same as “fog” point as it passes over cool surface. Diabatic Process Upslope fog Cooling of air as it flowsSame as “fog” upslope. Adiabatic process. Precipitation fog Increasing the water Same as “fog” vapor content of the air by evaporation from falling droplets. Adiabatic process Steam fog Mixing warm, moist air Same as “fog” with cold air. Adiabatic process. Clouds Usually by lifting of air Concentration of and adiabatic cooling. suspended droplets and/or ice crystals in air well above the surface 6. Lift Mechanisms: Convergent lifting Low pressure coming from flat land Horizontal movement toward a common location ` Convectional lifting Lifting that results from heating the air near the surface Free Convection – ascent of warmer air, especially as a result of surface heating o Lifts large amount of air quickly, thus the air is cooled quickly and made available for precipitation See diagram on p.42 of workbook! Onographic lifting Case of forced convection by which air is forced to rise when blown against a mountain range Upward displacement of air leads to adiabatic cooling and possible cloud formation Copious orographic precipitation takes place on windward side On the other side of the mountain, air descends the slope and warms via compression to create a rain shadow (area of lower precipitation) example of this is Death Valley! Frontal lifting Case of forced convection by which moving air (pushed by a pressure gradient) is forced to “override” colder air; therefore it is seemingly lifted by a cold-air wedge Fronts- Transition zones that exist where great temperature differences occur in relatively short distanes Results in the widespread development of cloud in 1 of 2 ways: o When cold air adcances towards warmer air (aka a cold front), dense cold air displaces light warm air o When warm air flows towards a wedge of cold air (aka a warm front), warm air is forced upward Free vs. Forced convection: Free Convection – warm air rising (less dense, lighter) naturally (p.42) Forced convection – air is PUSHED upwards - By a mountain range (orographic lifting) - Another air mass (frontal lifting) - Or convergence of different air masses Determining atmospheric stability: - As air parcel rises or sinks, it is subject to adiabatic cooling or warming - determining atmospheric stability involves comparing projected temperature of air parcel vs. the temperature of the surrounding air at some height where temperatures are available SO, IF: - Air parcel warmer than surrounding air -> unstable, air would rise o ELR > DALR DALR = 10C/1000m - Air parcel cooler than surrounding air -> stable, air would not rise o ELR < DALR DALR = 10C/1000m Stable atmosphere - air cools slowly upward and rising air cools faster - If air resists vertical motion, it is stable (although it can be forced to rise) - Stability occurs when cold air is beneath warm air - Atmosphere is stable if ELR < DALR o – all temperature inversions are stable - ex: in latter part of the night and near dawn, when the ground is cold from nighttime radiative cooling - normally, stable air does not produce clouds or precipitation 15 degrees / 1000 m = high ELR (more than 10) = unstable atmosphere because Unstable atmosphere - Air cools rapidly upward and rising air cools more slowly - If air is lighter (less dense) and rises without being forced, it is said to be unstable - Instability occurs when warmed air is beneath cold air o – ex: on a sunny afternoon, when ground is hot from absorbing solar radiation - Atmosphere is unstable if ELR > DALR - Cloud form if unstable air rises far enough to cool t dew-point temp and cause condensation (aka precipitation) Conditional stability - If “dry” (unstaturated) air resists upward motion but rises on its own after being saturated (relative humidity = 100%) - Clouds can form if air is lifted to its condensation level - DALR > ELR > WALR - “atmosphere may be stable but…” Neutral Atmosphere: - lifted parcel of air does not return to its original position nor continues to rise - ELR = ALR (wet or dry) - Temperature inside parcels matches temperature of surroundings Basic Cloud Types (p.46) Cumulus clouds – any cloud with substantial vertical development ** Stratus Clouds: - Horizontal, layered development in a stable atmosphere - Stability occurs at the surface and generally at least 2-3 km upward - Usually occur under cooler conditions or at least with a cooler surface, as a nighttime over a snow cover, or with a temperature inversion - More common under cooler conditions - Forms in layers of different stability (often low, but higher if air is dry) Altostratus – high stratus clouds Overcast – stratus clouds that cover the sky completely Nimbostratus – stratus clouds that produce rain Main types: cumulus, stratus, cirrus Nimb: producing rain Alto: high Cirrus Clouds: (Latin, means “curl”) - Well above 5km above surface - Formed entirely of ice crystals Halo around the moon – moon shining through the ice crystals of [often visible] cirro-stratus clouds; often an indication of approaching rain Cumulus clouds – clouds that form in warm conditions in unstable atmosphere - Even a “single” cumulus cloud can be very large - They grow over the coarse of the day - “thunderhead”: a tall cumulus cloud with a flattened top that is likely to produce a thunderstorm Infra-red is used for determining temperatures Clouds evaporate as air moves over high mountains Bottom of p. 46 “cold” upper-level cloud is composed mainly of snow Thunderstorm cloud – a cloud of vertical development with “cool” and “cold” portions (‘Warm” at bottom) 7. Precipitation requirements: Cooling, condensation, droplet growth Growth of cloud droplets: - collision-coalescence (warm clouds) o raindrops tend to stick together and get bigger o falling raindrops collect other drops as they fall (can also split apart) - Bergeron process (cold clouds) o snowflakes grow in size at the expense of liquid water droplets (automatically) o Through this continuous process, ice crystals will et bigger (bc water vapor deposited on them) while liquid water droplets will get smaller because they lose liquid water molecules - riming and aggregation Forms of Precipitation (p.49) - rain, including showers, drizzle, mist, etc. - freezing rain, glaze, ice storms - snow - sleet Conditions and precipitation types - riming, graupel and hail - virga Requirements for precipitation events: - water vapor in the air (humidity) - cooling below dew-point temp, which resuts in clouds; usually this cooling involves a lifting process (such as free convection) in an unstable atmosphere or foced vonvection, such as orographic lifting - Enough liquid water (cloud mass) that it becomes too heavy - Precipitation is released in the prescence of latent heat being given off Typical condensation nuclei R = 0.1 Typical cloud droplet R = 10 Large cloud droplet R= 50 How precipitation forms - Condensation around condensation nuclei - In warm clouds (T > 0C) mainly by collision-coalescence of falling water droplets to form larger droplets (heavier fall faster and collide more) - In cold clouds (T < 0C), mainlu ny the Bergeron Process: supercooled liquid water and ice crystals coexist – but supercooled water has a higher saturation bapor pressure tha ice, so there is a pressure force from water to the ice This causes the ice crystals to grow in size at the expense of liquid water, essentially producing snow Freezing in the atmosphere - Water in the atmosphere usually does NOT freeze until it is colder than 0C, usually colder than about -4C - This result is the occurrence of supercooled water (water still occurring as liquid below 0C) - Freezing usually requires ice nuclei onto which supercooled water (and other water) can freeze; these may or may not be abundant locally Bergeron Process (continuous process) 1. Water vapor is deposited onto snowflakes faster than molecules can escape (by sublimation); so snowflake grows in size 2. With decreasing water vapor in the cloud, molecules now escape (evaporate) from the liquid droplets faster than they can re- condense a. So the water droplets decrease in size and more water vapor is again available for deposition on the snowflakes 3. With more water vapor available, the snowflakes continue to grow a. The liquid droplets become smaller (with evaporation more in balance with condensation) - Snowflakes grow at the expense of liquid water due to greater vapor pressure (ability of molecules to escape), exerted by liquid water than by ice - Maximum difference at about -14C Snowflakes – six-sided crystals - Form best where the water-vs-ice vapor-pressure difference is the greatest (about -8C to -18C) Other precipitation processes: Riming and Aggregation - Formation of ice crystals requires freezing nuclei - Ice itself is a very effective nucleus Riming: freezing of super-cooled liquid water onto ice crystals - May occur in clouds as ice crystals falls and collide with super- cooled water droplets - May also occur on the ground Aggregation – adhesion of ice crystals (coalescence of liquid droplets) - Adhere best when ice has thin coating of liquid water - Snowflakes stick together and get bigger essentially - Aggregation greatest at temperatures not far below freezing (wet snow) Most frozen precipitation involves Bergeron process + riming and aggregation - Combination permits faster growth of ice crystals (into snowflakes) - Ultimate type of precipitation determined by what happens on the way down Precipitation type is determined by what happens on the water down - Rain and snow are straightforward - Sleet and glaze change closer to the surface Sleet comes from winter water fronts (I.e. warmer air above sub-freezing air) which creates bands of different precipitation types “banding effect” from rain to sleet to snow Other forms of precipitation: Rime: accumulations of frost occurring when super-cooled liquid water droplets (fog or cloud) freeze upon hitting other objects Graupel: larger “soft ice” resulting from rime accumulations on ice crystals, snowlflakes or sleet - Most common in windward maritime climates Hail: large ice pellets or lumps resulting from vertical recycling in turbulent thunderstorms Virga: any precipitation that evaporates before reaching the ground (common in very dry climates) Photosynthesis: growth process of green plants where water and CO2 are converted to carbohydrate, releasing oxygen in the process. Formula: CO2 + H20 -> CH20 + 02 (yields product through assistance of the sun) Water Vapor: Water in it’s gas phase; considered a ‘special feature’ of the lower atmosphere, contained entirely within the troposphere Updraft (“thermal”): upward current/draft of air (typically of warm air since warm air rises!) Cold-air advection: Air flow in which cold air is flowing into a region of warmer air Collision-coalescence Process – precipitation growth process where droplets collide and merge into a larger droplet Oxygen – A reactive gas essential for life comprising approximately 21% of the atmosphere. Respiration – Biological process that combines oxygen with carbohydrate to produce energy, releasing water-vapor and carbon dioxide as by products; C H O + 6O -> 6CO + 6 H O + energy (energy = 36 or 38 ATP) Troposphere – lowest temperature layer of the atmosphere, from the surface to about 16km, characterized by generally decreasing temperatures with increasing altitudes; heated by earth’s surface Ozone – molecules consisting of three oxygen atoms, most abundant in the middle and upper stratosphere (aka ozone layer) Radiation (electromagnetic) – energy emitted by virtue of an object’s temperature, found in electromagnetic waves (e.g. light), which contain electric and magnetic components; travels at 30,000km/sec; t Conduction – heat transfer from molecule to molecule, without significant movement of the molecules Reflection – process in which radiation arriving at a surface bounces back, without being absorbed or transmitted. Reflection does not heat the reflector Insolation – Incoming solar radiation Greenhouse Effect – Result of clouds and greenhouse gases (mainly water vapor and carbon dioxide), which absorb longwave radiation and cause near- surface temperatures to be much higher than they otherwise would be - “Greenhouse gases” such as CO2 and methane absorb L wavelengths but not K or K, this means that most of that energy is retained in the earth-atmosphere system, causing Earth to heat up Isobar – A line on a weather map connecting points of equal pressure; moving along an isobar there will be no changes in pressure; pressure force gradient acts perpendicular in isobars Subsidence - Vapor content (of air, actual) - Unsatrated “dry” air- Evaporation rate - Oasis effect - Unstable atmosphere - Air cools rapidly upward and rising air cools more slowly - If air is lighter (less dense) and rises without being forced, it is said to be unstable - Instability occurs when warmed air is beneath cold air o – ex: on a sunny afternoon, when ground is hot from absorbing solar radiation - Atmosphere is unstable if ELR > DALR - Cloud form if unstable air rises far enough to cool t dew-point temp and cause condensation (aka precipitation) Stratus clouds - Horizontal, layered development in a stable atmosphere - Stability occurs at the surface and generally at least 2-3 km upward - Usually occur under cooler conditions or at least with a cooler surface, as a nighttime over a snow cover, or with a temperature inversion - More common under cooler conditions Begeron process – primary mechanism for precipitation formation outside the tropics; involvs the coexistence of ice crystals and supercooled water droplets Sleet – precipitation in the form of ice pellets, resulting when rain drops freeze before reaching the surface Carbon dioxide – An important greenhouse gas, Decomposition Stratosphere – layer of the atmosphere between about 16 and 50 km, characterized by generally increasing temperature with increasing altitude; heated by absorption of sunlight by ozone (primarily UV absorption) Latent heat – energy bound or freed when matter changes state; energy input may be in any form, energy release is as sensible heat; transferred by convection - Convection: heat transfer by fluid flow Absolute zero – lowest temperature theoretically possible; 0 on the Kelvin scale, -273C; all molecular motion would be frozen Blackbody – An object or substance that is perfectly efficient at absorbing and radiating radiation. Blackbodies do not exist in nature (they just represent an ideal) - Absorbs all incoming light and does not admit any - Considered ‘perfect emitters of radiation’ - Temperature determines how much energy a blackbody radiates - Emissivity: percentage of energy radiated by a substance relative to that of a blackbody Re-radiation Longwave radiation - (also known as infrared radiation) – electromagnetic radiation at wavelengths longer than visible radiation Temperature inversion – Condition in which temperature increases with increasing altitude; all temperature inversions are stable! Maritime climate ** Wind – horizontal movement of air; caused by pressure gradient force - Pressure gradient force is driving air from areas of higher barometric pressure (more dense air) to areas of lower barometric pressure (less dense air), thereby causing winds. Without a pressure gradient force, there would be no winds - HIGH pressure -> clear skies (clouds blown away) - LOW pressure -> cloudy skies (clouds concentrated) Geostrophic wind/flow – an idealized condition where the upper-level air flows at constant speed and direction; parallel to straight isobars. There is no acceleration in a geostrophic flow and negligible frictional forces Conditional instability- Happens when ELR is between the dry and saturated adiabatic lapse rates - Tendency for a lifted parcel to sink or continue rising depends on whether or not it becomes saturated and how far it is lifted Cirrus clouds - (Latin – “to curl”) Well above 5km above surface; Formed entirely of ice crystals Rain – precipitations arriving at surface in the form of liquid drops, usually between .5 and 5 mm; outside of the tropics, rain usually begins at the ice stage and melts before reaching the surface Virga – rain that falls into a layer of warm dry air and evaporates before reaching the surface Converting between temperatures: C = 5/9 (F – 32) F = (9/5 C) + 32 Fahrenheit Celsius 14 -10 32 0 50 10 68 20 86 30 104 40 Atmospheric Scattering: Rayleigh Scattering: scattering by agents substantially smaller than the radiation’s wavelength; visible radiation scattering by air molecules; scatter shorter wavelenths - Clear skies appear blue because people are seeing more scattered blue light than any other color - Sunrises and sunsets appear red for the same reason Mie Scattering: scattering by dust and aersols (larger than air molecules), which does not favor particular visible wavelenths and scatters mostly “forward” (downward) - Hazy sky appears whitish because all wavelengths are being scattered downward Moon’s sky appear black because it has no atmosphere, thus there is no scattering
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'