Exam 2 notes - Brian Szuster PDF

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Brian Szuster...

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2/11/14

Chapter 4: Atmospheric circulation  

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DIDN’T WRITE EVERYTHING ON THE SLIDES Atmospheric pressure: weight of the atmo bearing down on all surfaces o Sea level—1,013 mb o Measured using a barometer Wind: horizontal movement of air across earth’s surface o Turbulence adds vertical updrafts and downdrafts o Horizontal movements of air (wind) are produced by differences in air pressure between locations on the earth’s surface  Moving from high to low air pressure  Heating of Earth creates pressure differences o Measured with an anemometer expressed in kilometers per hour  Beaufort Wind Scale o Described by where it’s coming from o Direction measured with a wind vane Air movement o Redistributes heat and resolves energy imbalances through 3 levels of atmospheric circulation:  Primary—general movement (global)  Secondary—migratory high and low pressure systems (regional)  Tertiary—local winds and weather Local circulation  Important o Temperature, pressure, air movement o Heating at the surface creates expansion in the atmosphere and pushes the isobaric surfaces upward, creating a pressure gradient along lines of equal elevation. A simple convective loop is formed by this pressure gradient o Isobar: line of equal pressure o Makai-mauka winds  Makai: hot air rises over land, and cooer air over water is drawn toward the chore  Mauka: nighttime. Warm air over ocean rises, cooler air over mountains falls and is drawn offshore o Mountain-valley winds Hypothetical pressure gradient winds  Important slide Forces that act on wind  Important. Know the 5 forces. o Gravitational force (G)  Gravitational force on the atmo is almost uniform  Gravity compresses the atmo near the ground equally around the world  Vertical pressure gradient is much larger than horizontal pressure  It slows the vertical movement of air o Centrifugal force (Ce) (don’t worry about it)  Newton’s First Law of Motion: objects at rest will remain at rest…  Wind tends to move in a straight path

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o Pressure Gradient force (PG)  Pressure gradient: difference in atmospheric pressure… o Coriolis force (Co)  Deflects any object moving on earth from going in a straight path  Caused by earth’s eastward rotation and closely related to momentum  Moving objects in the N Hemisphere are deflected to the right, S hemisphere deflected to the left o Friction force (F)  The motion of air near the earth’s surface is slowed by drag—friction  Effects wind up to about 500 meters from earth’s surface  Friction counters Coriolis force near the surface o Net force = add up the letters above Secondary Circulation Patterns  Important slide o Know which way the wind goes in high and low pressure

 February 13, 2014 Hurricane Sandy video NOVA http://www.pbs.org/wgbh/nova/earth/inside-the-megastorm.html Hurricanes are systems that are born in the tropics, and they need to have 26 degrees Celsius, approximately 80 degrees Fahrenheit, water to get the systems going. They actually act as a heat engine. They take the warm water, and it rises up as water vapor. And as that water vapor condenses, it releases latent heat into the atmosphere, and that’s where the wind energy is coming from.

February 20, 2014 Global Climate PPT? Modern climate classifications systems recognize:  Genetic factors  Empirical factors  There are 6 major categories and some sub-categories according to the Köppen o Remember the letters. They’re combined to describe everything o Remember the order of the combos  ITCZ—Inter Tropical Climate Zone? February 25, 2014  Put notes for ch. 4 atmospheric stuff up in the above day

Ch. 4 Global circulation PPT Part 1: Atmospheric circulation  Focus on tropical Part 2: oceanic circulation  El niño, la niña

February 27, 2014 Ch. 5: Humidity, condensation and precipitation  Important PPT  Hydrologic cycle—most evaporation happens on the ocean. Water vapor moves horizontally, called advection  Humidity’s 3 parts and how to calculate one of them  remember. o Relative humidity: compares actual amount of water in air to the maximum capacity. Actual vs. potential. Usually highest at dawn actual wat er vapor content ofair ∗100 RH = maximum water vapor capacity  Air is saturated when it holds the max water vapor at a given temp.  Dew-point temperature: point where air becomes saturated o Specific Humidity: mass of water vapor held by a mass of air. Measured in grams of water per kilogram of air o Vapor pressure: the %age of air pressure that’s from water molecules  Saturation  Atmospheric stability o Stable, unstable, conditionally unstable o Depend on ____ rates  Convection in a lava lamp o Orange goop  Adiabatic processes—4 lapse rates:  Important slide o Normal (not important): average cooling rate of calm air with increasing altitude o environmental: important rate. actual lapse rate at a given time & location that can vary under the influence of local weather conditions o dry adiabatic (DAR) 10 C° /1000m (RH < 100) o moist adiabatic (MAR) 6 C° /1000m (RH = 100) o why is MAR < DAR?

March 4, 2014 06 Moisture: Ch 5 (review and continued)  Slide 2: 3 phase changes of water o What stores and what releases heat  Slide 8, 12, 13 o 3 humidities, 1 equation  Slide 17 3 (main) Stability Conditions o Slide 18  Part 4: Lifting Mechanisms o 4 types  Slide 28: 3 types of clouds Weather

March 6, 2014

Exam Review Air   

Air pressure Wind—horizontal and vertical Measuring wind o Different measurements  MOVEMENT. o Heat around the equator has to be circulated towards the poles o 3 levels of atmospheric circulation  Local circulation slide o Forces that act on wind: 5 factors  Gravitational  Centrifugal  Pressure gradient: air moves from high pressure zone to low PZ  Hp: down and out  Lp: ascending, convergent  Coriolis: further from equator = more deflection  Friction: drag. Counters coriolis force Global circulation  4 pressure bands o concentrate on the one around the equator o inter-tropical convergence zone  Monsoons o Equatorial and tropical  Oceanic circulation o Clockwise in northern hemisphere, counter in southern o Deep ocean circulation  Upwelling o ENSO: El Niño Southern Oscillation  Know wet and dry areas  La: stronger than normal. Rain near… australia  El: strong flipped. Rain near south america Moisture  Evaporating water—heat absorbed  Condensation—release energy  Humidities o Relative humidity  Greater temp = larger max capacity  Dew point—where the air is saturated and there’s condensation o Specific humidity—measure of how much water is in a mass of air o Vapor pressure—percentage of air pressure derived from water molecules  Atmospheric stability

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4 Lifting mechanisms o Convectional  Heat rises o Cyclonic (convergence)  Air spins up o Frontal  Cold air pushes hot air up o Orographic  Geographic barrier  4 lapse rates, 3 conditions  Clouds o Classified by shape, altitude, precipitation Weather  Define air masses—moisture and temperature  Slide 5—he talked about the shapes  Slide 6: 4 stages  Zipper  Subtropical cyclones west to east, rainy  Violent weather o Tornado season coming up o All kinds of lifting. Unstable atmosphere o Fujita scale for tornadoes F0-F5 o Saffir/Simson Hurricane scale Category 1-5 Climate  Slide 3  Köppen climate classification o Major: 6: A-H. know them.  TDMMPH o Know temperature and precipitation o Know tropical subcategories  Af: tropical rain forest  Am: tropical monsoon  Aw: tropical savanna  Hawaii climates...