ATM OCN 100/101 Homework 03 PDF
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This document provides an overview of the ATM OCN 100/101 course, specifically exploring the vertical structure of the atmosphere. Concepts like pressure, density, and temperature are defined and examined in relation to atmospheric mass. The document introduces vertical soundings to measure atmospheric temperature changes with height.
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8/20/24 ATM OCN 100 / 101 Vertical Structure of the Atmosphere Pressure and Density in the Atmosphere Vertical Soundings – Vertical Structure of...
8/20/24 ATM OCN 100 / 101 Vertical Structure of the Atmosphere Pressure and Density in the Atmosphere Vertical Soundings – Vertical Structure of Temperature in the Atmosphere 1 Learning Objectives Describe the vertical structure of the atmosphere Describe how pressure, density, and temperature vary with height in our atmosphere Explain how pressure and atmospheric mass relate to each other Describe and explain the atmospheric temperature structure from the surface through the thermosphere 2 What is the atmosphere? A fluid A thin layer of air surrounding the Earth Mainly a mixture of invisible gas with some solid and liquid particles, that stays in place due to the force of gravity https://www.nasa.gov/image-feature/hurricane-irma 3 1 8/20/24 90% of Earthʼs atmosphere (by mass) is below 16km (10mi) 4 Learning Objectives Describe the vertical structure of the atmosphere Describe how pressure, density, and temperature vary with height in our atmosphere Explain how pressure and atmospheric mass relate to each other Describe and explain the atmospheric temperature structure from the surface through the thermosphere 5 Density and Pressure Definitions: Mass: A measure of the amount of matter of an object or substance (kg) Volume: The amount of space that a particular object or substance occupies (m3) Density: The amount of mass per unit volume (kg / m3) Density = Mass / Volume 6 2 8/20/24 Density and Pressure For the atmosphere, density is used to measure the amount of air (mass) per unit volume (units = kg / m3) Near the surface, air density is about 1.2 kg/m3 High Density Low Density 7 Definition: Pressure: Force applied per unit area Pressure = Force / Area 8 Definitions: Pressure: Force applied per unit area Pressure = Force / Area Changes are large in the vertical direction Does not vary much in the horizontal, BUT! Horizontal variations are essential for wind / weather! Global average “Sea Level Pressure” = 1,013 mb (millibar) Units: 1,013 mb = 1 atm (1 atmosphere) 1,013 mb = 101,300 Pa (Pascal) [1 Pa = 1 kg / (m s2)] (Note: 1mb = 100Pa) 1,013 mb = 1,013 hPa (Hectopascal) [1 hPa = 100 Pa] 1,013 mb = 29.92 in Hg (inches of Mercury) 9 3 8/20/24 Learning Objectives Describe the vertical structure of the atmosphere Describe how pressure, density, and temperature vary with height in our atmosphere Explain how pressure and atmospheric mass relate to each other Describe and explain the atmospheric temperature structure from the surface through the thermosphere 10 Pressure: Force applied per unit area Pressure = Force / Area Concept: Pressure balances gravity In the atmosphere, pressure is very closely Weight of approximated as the weight of the ATM atmosphere (force due to gravity) above a unit area. Unit Area 11 Application: What is the Mass (in kg) of a 1m2 column of air that extends from the surface to space? Weight = Mass ⨉ g (Note: g = gravitational acceleration = 9.8 m/s2) Weight of Area = 1 m2 ATM Unit Area 12 4 8/20/24 Application: What is the Mass (in kg) of a 1m2 column of air that extends from the surface to space? Pressure = Weight / Area = 101,300 Pa Pressure = Mass ⨉ g / Area = 101,300 Pa Weight of ATM Rearrange: Mass = Pressure ⨉ Area / g = 101,300 (Pa) ⨉ 1 (m2) / 9.8 (m/s2) ≅ 10,300 kg Or… about 10 tons of air per square meter! Unit Area 13 Pressure is a good measure of the amount of atmosphere (by mass) that is above or below you at a given elevation. As a result, pressure is often used as a vertical coordinate. Assuming a surface pressure of 1000mb, if you are at: 1000mb: you are above 0% of the atmosphere, and below 100% 700mb: you are above 30% of the atmosphere, and below 70% 200mb: you are above 80% of the atmosphere, and below 20% 14 Ocean Pressure in the Ocean: (recall, pressure supports weight of fluid above a given area) Concept: Incompressible fluid Ocean water is (close to) incompressible, Equal Mass so equal “blocks” of water have the same mass. è Pressure increases linearly with depth in the ocean 10m of ocean = one atmosphere 15 5 8/20/24 Ocean Equal Mass 16 Concept: Compressible fluid The atmosphere is a “compressible fluid”. Gravity gives the atmosphere weight, which pushes downward on air below, compressing the air below. As a result, density increases as you move Density Density downward in the atmosphere. Increases Decreases Downward Upward Equivalently, density decreases as you move upward in the atmosphere. 17 % Mass Atmosphere: air IS compressible: BELOW Layer Atmosphere density and pressure decrease 99% (~exponentially) with height % Mass in Layer.. Equal Mass. 6.25% 12.5% 75% 25% 50% 50% 25% 0% 18 6 8/20/24 Learning Objectives Describe the vertical structure of the atmosphere Describe how pressure, density, and temperature vary with height in our atmosphere Explain how pressure and atmospheric mass relate to each other Describe and explain the atmospheric temperature structure from the surface through the thermosphere 19 Vertical “Sounding” Vertical Sounding: measurement of how temperature changes with height in the atmosphere. Weather balloons lift “radiosondes” into the air Data compiled into “Soundings” 20 Radiosondes / Rawindsondes Attached to balloon Measures: Temperature Humidity Pressure Rawindsonde: Sends back information about position (we can infer wind) 21 7 8/20/24 Vertical Sounding Definitions: Lapse Rate: Rate at which temperature decreases with height (positive when temperature gets colder with height). Typically ~6.5C/km in the troposphere AAACH3icbVBNS8NAEJ3Ur1q/ol4EL4tF8NKSiKgXoehBjwqtFZpQNtuNLt1Nwu5GaEP+iRf/ihcPiog3/43btAdtfbDsmzczzMwLEs6UdpxvqzQ3v7C4VF6urKyurW/Ym1u3Kk4loS0S81jeBVhRziLa0kxzepdIikXAaTvoX4zy7UcqFYujph4k1Bf4PmIhI1gbqWsfe5dYCIzOUM1FnmaCKuSFEpOs2c2aOaoh85/neTachMMi7NpVp+4UQLPEnZBqYwcKXHftL68Xk1TQSBOOleq4TqL9DEvNCKd5xUsVTTDp43vaMTTCZhE/K+7L0b5ReiiMpXmRRoX6uyPDQqmBCEylwPpBTedG4n+5TqrDUz9jUZJqGpHxoDDlSMdoZBbqMUmJ5gNDMJHM7IrIAzbuaGNpxZjgTp88S24P6+5x/ejmqNo4H7sBZdiFPTgAF06gAVdwDS0g8AQv8Abv1rP1an1Yn+PSkjXp2YY/sL5/ABu/oeY= TT TB = 1⇥ zT zB Temperature Inversion: Vertical layer of the atmosphere where temperature increases with height 22 23 Thermosphere Structure of the Atmosphere “Typical” Temperature Mesopause Mesosphere Stratopause Stratosphere Tropopause Troposphere 24 8 8/20/24 Thermosphere Mesopause Mesosphere Stratopause Stratosphere Tropopause Troposphere 25 Thermosphere Troposphere: “Turning” sphere Where weather happens Mesopause Heated from below Lapse rate: ~6.5°C/km Tropopause: Where temperatureMesosphere stops decreasing with height (isothermal layer) Stratopause -> ~16km in the tropics -> ~6km in polar regions Stratosphere Tropopause Troposphere 26 Thermosphere Mesopause Mesosphere Stratopause Stratosphere Ozone Maximum Tropopause Troposphere 27 9 8/20/24 Stratosphere: Stratum “layer” Thermosphere Not much vertical motion (no weather) Temperature increases with height (inversion) Mesopause -> Heated from above by ozone Stratopause: Where temperature stops increasing -> ~50 km in the tropics Mesosphere Stratopause Stratosphere Ozone Maximum Tropopause Troposphere 28 Why is temperature highest at 50km, while ozone Thermosphere maximum is at 25km? There is enough ozone at 50km to absorb most of the Mesopause incoming UV radiation, so there is less UV radiation to be absorbed at 25km Mesosphere Stratopause Enough Ozone Stratosphere Ozone Maximum Tropopause Troposphere 29 Thermosphere Mesopause Mesosphere Stratopause Stratosphere Tropopause Troposphere 30 10 8/20/24 Thermosphere Mesopause Mesosphere Stratopause Stratosphere Tropopause Troposphere 31 Learning Objectives Describe the vertical structure of the atmosphere Describe how pressure, density, and temperature vary with height in our atmosphere Explain how pressure and atmospheric mass relate to each other Describe and explain the atmospheric temperature structure from the surface through the thermosphere 32 33 11 8/20/24 34 35 12 9/9/24 ATM OCN 100 / 101 Week 2: Atmospheric Constituents Atmospheric Composition Origin of the Atmosphere The Carbon Cycle and Climate Change 1 Learning Objectives Use a budget equation to explain how the concentration of a gas relates to its sources and sinks What gasses form our atmosphere? Permanent and Variable Gasses Sources and sinks of various gasses Explain some important sources and sinks of permanent and variable gasses in our atmosphere 2 We can think of the atmosphere as a giant reservoir of gasses that are constantly being exchanged with the hydrosphere, lithosphere, and biosphere 3 1 9/9/24 Concept: Budget Equation: Change in Source concentration of = - Sink (rate) (rate) a gas (in time) Definitions: Concentration: the amount of a particular gas in a given volume. Usually percent (parts per 100), or ppmv (parts per million, by volume). 1ppmv =.0001% A Source is a process that adds a gas to the atmosphere A Sink is a process that removes a gas from the atmosphere 4 Concept: Budget Equation Change in Source Sink concentration of = (rate) - (rate) a gas (in time) IF: Source > Sink: Concentration increases Source < Sink: Concentration decreases Source = Sink: Concentration stays the same 5 Learning Objectives Use a budget equation to explain how the concentration of a gas relates to its sources and sinks What gasses form our atmosphere? Permanent and Variable Gasses Sources and sinks of various gasses Explain some important sources and sinks of permanent and variable gasses in our atmosphere 6 2 9/9/24 What gasses are in the atmosphere? Permanent Gas: Does not vary (substantially) in space or time Figure T01: Composition of the Atmosphere 7 What gasses are in the atmosphere? Variable Gas: concentration varies in space and / or in time Figure T01: Composition of the Atmosphere 8 Nitrogen: 78% Source: bacterial denitrification during decay of biological material, volcanoes: Source of N2 Note: Atmospheric Nitrogen (N2) is VERY Sink: N-fixation by lightning, chemically stable, so it accumulates fires, or bacteria: Sink for N2 through time: Large Reservoir 9 3 9/9/24 Oxygen: 21% Sources: Photosynthesis: Photolysis: Sinks: Fires, Oxidation, decomposition, respiration 10 Global distribution of photosynthetic activity 11 Figure T01: Composition of the Atmosphere 12 4 9/9/24 Water in the Atmosphere In gas phase, it is invisible Variable concentration The most important Greenhouse Gas 13 Hydrologic Cycle for the Atmosphere: Source: Evaporation (oceans, lakes) Transpiration (vegetation) Sink: Precipitation Locally: Transport can be a source or sink Water returns to ocean via precipitation and river runoff 14 Total precipitable water: Water Vapor Concentration Varies by location 15 5 9/9/24 What gasses are in the atmosphere? Variable Gas: concentration varies in space and / or in time 0.0419 %, or 419 ppm (parts per million) Figure T01: Composition of the Atmosphere 16 Plant growth Plant decay during summer during winter 17 Carbon Dioxide Greenhouse Gasses: “Trap” energy in lower atmosphere Anthropogenic: Caused by human activity Greenhouse gasses are increasing C harles K eeling 18 6 9/9/24 What gasses are in the atmosphere? Variable Gas: concentration varies in space and / or in time Important Greenhouse Gasses! 19 What gasses are in the atmosphere? Variable Gas: concentration varies in space and / or in time 20 Ozone in the Troposphere: Produced when Nitrogen Oxides (NOx) and Volatile Organic Compounds (VOCs; or hydrocarbons) interact in the presence of sunlight Counties in the U.S. with high ozone concentrations in 2009 https://sphw eb.bum c.bu.edu/otlt/M PH-M odules/PH/RespiratoryHealth/RespiratoryHealth7.htm l https://w w w.epa.gov/ozone-pollution-and-your-patients-health/w hat-ozone 21 7 9/9/24 Ozone in the Stratosphere: Ozone is naturally produced in the stratosphere as ultraviolet radiation interacts with molecular oxygen (O 2). Ozone is also destroyed via interactions with ultraviolet radiation. Natural Source Natural Sink 22 Ozone absorbs UV radiation in the stratosphere: Stratospheric Ozone plays an important role in protecting Earth’s surface from life-damaging ultraviolet radiation. Incoming UV Radiation 23 Application: The Stratospheric Ozone Hole When sunlight reacts with certain chemicals (e.g. CFCs), “Ozone depleting Substances” (ODS’s) are produced. Polar stratospheric clouds (late winter) are especially effective at producing ODS’s via chemical reactions on ice crystals. 24 8 9/9/24 Application: The Stratospheric Ozone Hole These Ozone Depleting Substances catalyze the Late Winter destruction of ozone in the stratosphere via interactions with Early Spring ultraviolet radiation. This requires solar radiation, so it begins in early Spring, as soon as the sun rises in the polar regions. 25 Aerosols: particles suspended in air (dust, soot, salt) Provide “nucleus” for cloud droplet formation (cloud condensation nuclei, or CCN) Can shade surface, contribute to poor air quality, etc. 26 Aerosols interact with water vapor in the atmosphere to form cloud particles. More cloud particles make clouds “brighter”, so they reflect more solar radiation. Less solar radiation cools the planet. 27 9 9/9/24 Learning Objectives Use a budget equation to explain how the concentration of a gas relates to its sources and sinks What gasses form our atmosphere? Permanent and Variable Gasses Sources and sinks of various gasses Explain some important sources and sinks of permanent and variable gasses in our atmosphere 28 Friedlingstein et al.: G lobal Carbon Budget 2019, Earth Syst. Sci. Data, 11, 1783–1838, https://doi.org /10.5194/essd-11-1783-2019, 2019. 29 The Global Carbon Budget (Atmosphere) NOTE: To convert GtC to GtCO2, multiply by 44/12 (the ratio of atomic weights) To convert GtC to ppm, divide by 2.13 (explanation is a little more involved) Sources: Sinks: Land: +120 GtC per yr Land: +123.2 GtC per yr Land Use: +1.5 GtC per yr Ocean: +90 GtC per yr Ocean: +92.5 GtC per yr Volcanoes: +0.1 GtC per yr Fossil Fuels: +9 GtC per yr TOTAL: +220.6 GtC per yr TOTAL: 215.7 GtC per yr ATMOSPHERE GAINS 4.9 GtC PER YEAR è CONCENRATION INCREASES 30 10 8/21/24 ATM OCN 100 / 101 Week 2: Atmospheric Constituents Atmospheric Composition Origin of the Atmosphere The Carbon Cycle and Climate Change 1 What gasses are in the atmosphere? Permanent Gasses: Do not vary (substantially) spatially or temporally Figure T01: Composition of the Atmosphere 2 What gasses are in the atmosphere? Variable Gas: concentration varies spatially and / or temporally Figure T01: Composition of the Atmosphere 3 1 8/21/24 Why so much Oxygen? And so little CO2? Venus and Mars both have about 95% CO2 and about 5% N2. Early Earth likely looked very similar. What happened? 4 Learning Objectives Describe the evolution of Earth’s atmosphere over the last 4.5 Ga (1 Ga = 1 billion years) Explain the various processes that are responsible for the evolution of Earth’s Atmosphere Why is there so little Carbon Dioxide? Why is there SO MUCH Oxygen? Explain how life on Earth has changed the atmospheric composition 5 Evolution of the Atmosphere Note: 1Ga = 1 billion years ago Hadean: 4.6Ga – 4Ga Influenced by formation of the solar system, Moon formation “event”, bombardment / volcanic outgassing Archean: 4Ga – 2.5Ga Volcanic outgassing, gradual oxidation of the mantle, origin of life Great Oxidation Event: Rapid increase in Oxygen about 2.3Ga Present (Proterozoic / Phanerozoic): 2.5Ga - Present Life! Loss of Carbon Dioxide, increase in Oxygen and Ozone 6 2 8/21/24 The (really) Big Bang 7 8 Earth’s first ATM – pre-moon formation Hadean Atmosphere: Bombardment / Accretion from solar nebula Source: Accretion / gravitational attraction of whatever was in the solar nebula. Primarily H2, He, some N (nitrogen), C (carbon) and O (oxygen) Sink: Lighter gasses escape to space Evidence: Comparison with outer planets like Jupiter, Saturn, Uranus, Neptune. 9 3 8/21/24 Moon Formation Event Mars-sized planet collides with Earth around 4.5Ga Oceans vaporize immediately Atmosphere and whatever oceans may have existed were lost within hours. Differentiation: densest material (Iron and Nickel) form core and mantle; light elements driven to the surface to form oceans / atmosphere 10 Hadean Atmosphere (4.5-4.0Ga) Hadean Atmosphere (4.5 – 4.0Ga): Bombardment / Volcanism Sources: Bombardment / volcanic activity provides CO, CO2, H2, H2O, Nitrogen Sinks: H2 escapes to space, H2O condenses into oceans. Note: Earth’s mantle was likely less oxidized (less oxygen) than present, so more H2 (rapidly lost) and CO than present. 11 Archean Atmosphere (4.0 – 2.5Ga) Archean atmosphere inherits what was present at the end of the Hadean. Bombardment slows down, but volcanism continues Atmospheric composition during the Archean: CO2 & CO: ~80% ç Where did all the CO2 go? H2O: ~10% N2 ~10% Other gasses… 1 to 10 atmospheres worth of CO2 – surface temperature of 85°C Where did the CO2 go? What are we missing? 12 4 8/21/24 What happened to all of Earth’s CO2? Chemical Weathering: CO2 dissolves in water, forming Carbonic Acid. Carbonic acid interacts with Silicate rocks, forming ions that are transported to the ocean, used by plankton (shells), fall to the ocean floor, and become sedimentary rocks. Plate Tectonics: Carbonate are rocks “recycled” into Earth’s mantle via tectonic activity 13 What about Oxygen? Before ~2.5Ga, evidence suggests very little oxygen in our atmosphere (< 0.1%). Around 2.4-2.1Ga, Oxygen levels increased dramatically during the “Great Oxidation Event”. Why? https://uwaterloo.ca/wat-on-earth/news/earths-oxygen-revolution 14 What about Oxygen? Why didn’t O2 build up prior to 2.3Ga? 1. Sinks prior to 2.3 Ga quickly depleted whatever O2 was produced Mineral oxidation (Iron especially) Atmospheric processes (methane and ammonia) 2. Biological Activity Evolution of oxygenic photosynthesis Eukaryotic cells – more complex life! https://uwaterloo.ca/wat-on-earth/news/earths-oxygen-revolution 15 5 8/21/24 Rise of Oxygen: Evidence Red Beds GRE Form in more oxygen-rich AT O environments (1-2% ATM) Start around 2 Ga XID ATIO EVEN Banded Iron Formations: NT Bands of magnetite (Fe3O4) and (2.4 silicate (iron poor) -2.1 Form in oxygen-depleted water environments (< 1%) Ga) Stop around 2 Ga 16 Evidence for cyanobacteria Ancient (3.5Ga) rock formations from the Warrawoona Group (Australia) may be stromatolites... But evidence of fossil cyanobacteria is sketchy… Likely, anoxic bacteria during early earth. 17 Evidence for early cyanobacteria Gene sequencing to reconstruct ancestral lines, combined with evolutionary age models, suggest multicellular cyanobacteria emerged just before the Great Oxidation Event. 18 6 8/21/24 Earthʼs Present Atmosphere: the Proterozoic (2.5Ga – 0.55Ga) Life! Life begins ~3.8 - 3.5 Ga, but likely utilized anoxygenic photosynthesis (O2 was not a byproduct). Oxygenic photosynthesis: uses a ”donated” electron from H2O; O2 produced as byproduct. Cyanobacteria: blue-green algae Oxygen levels increase to ~1-2% of present levels 19 Why no life on land? First plants arrive on land around 500 Mya Ultraviolet Radiation doesn’t permit life on land, or in surface oceans O3 (ozone) layer is needed! O2 + photon (λ < 240 nm) → 2 O O + O2 + M → O3 + M Once O2 levels reach 1-2%, there is “enough” oxygen for ozone to form. Rhynia gw ynne-vaughanii, 400 m illion-year-old fossil plant stem from This allows evolution of life on land. Aberdeenshire, Scotland. Im age credit: Natural History M useum , London. From https://w w w.sci.news/biology/first-land-plants-05740.htm l 20 Figure T01: Composition of the Atmosphere 21 7 8/21/24 Evolution kicks in… As O2 increases, O3 increases via photochemical reactions ==> Ozone layer! What next? Early life: anaerobic bacteria (photosynthesis) Aerobic bacteria develop ~2 Ga (respiration!) Eukaryotic cells develop (~1.5-2 Ga) ~0.5-1.5Ga, meiosis (sexual reproduction)… Evolution ==> diversity! 22 ~600Ma – present: Life takes off!!! 23 Figure T01: Composition of the Atmosphere 24 8 8/21/24 Learning Objectives Describe the evolution of Earth’s atmosphere over the last 4.5 Ga (1 Ga = 1 billion years) Explain the various processes that are responsible for the evolution of Earth’s Atmosphere Why is there so little Carbon Dioxide? Why is there SO MUCH Oxygen? Explain how life on Earth has changed the atmospheric composition 25 9 9/13/24 ATM OCN 100 / 101 Week 2: Atmospheric Constituents Atmospheric Composition Origin of the Atmosphere The Carbon Cycle and Climate Change 1 Learning Objectives Describe some major features of the global carbon cycle Explain the difference between a reservoir of carbon, and a flux of carbon. How do they relate to each other? Describe where anthropogenic sources of carbon dioxide are coming from, both regionally and via sectors. Describe some possible “solutions” for reducing greenhouse gas emissions 2 1 9/13/24 What gasses are in the atmosphere? Variable Gas: concentration varies in space and / or in time 0.0421 %, or 421 ppm (parts per million) Figure T01: Composition of the Atmosphere 3 Budget Equation: Change in Source Sink amount of a gas = (rate) - (rate) (through time) Definitions: Reservoir (amount): the amount of carbon stored in a given system. In the atmosphere, we also refer to this as concentration. Flux (sources / sinks): Rate at which carbon is being transferred from one reservoir to another. Net Flux: Sum of all sources and sinks Anthropogenic: Generated by humans 4 2 9/13/24 Budget Equation: Because Earth is a closed system (no transport of Carbon to or from Earth from space) we can describe the amount of carbon in, or fluxed to or from, a reservoir or in terms of the total amount of carbon. Reservoirs: Amount / Concentration Units 1 GtC = 1 billion tonnes Carbon = 1,000,000,000kg C = 1 PgC 1 GtCO2 = 12/44 GtC = 0.27 GtC 1 ppmv = 2.13 GtC Flux (source or sink) or change in time units: Usually GtC per yr or GtCO2 per yr. Occasionally ppmv per year 5 The Global Carbon Cycle Reservoirs: Carbon is “stored” in the atmosphere, ocean, and land. Atmosphere: 589 GtC Ocean: 50,000 GtC Soils / Veg: 2,500 GtC Permafrost: 1,700 GtC Fossil Fuels: 1,700 GtC https://www.noaa.gov/education/resource-collections/climate/carbon-cycle 6 3 9/13/24 The Global Carbon Cycle Fluxes: Carbon is constantly being exchanged between the atmosphere, ocean, and land. Land / Atmosphere: Photosynthesis / Respiration dominates land cycle, and nearly balance. Some net flux to soils / vegetation. https://www.noaa.gov/education/resource-collections/climate/carbon-cycle 7 The Global Carbon Cycle Ocean / Atmosphere: Carbon dioxide enters and leaves the ocean directly through air/sea fluxes. Ocean / Land: Carbon moves from land to the ocean via river runoff, and from the ocean to land via sedimentation. https://www.noaa.gov/education/resource-collections/climate/carbon-cycle 8 4 9/13/24 The Global Carbon Cycle Ocean Carbon Pump: Phytoplankton use carbon in photosynthesis, and some are eaten by zooplankton and other life. As plankton die and dissolve, they return most of that carbon to the ocean (dissolved organic carbon). But some marine matter sinks to the seafloor, returning to the lithosphere. https://www.noaa.gov/education/resource-collections/climate/carbon-cycle 9 Chemical Weathering: (~100 million year) Chemical Weathering: CO2 dissolves in water, forming Carbonic Acid. Carbonic acid interacts with Silicate rocks, forming ions that are transported to the ocean, used by plankton (shells), fall to the ocean floor, and become sedimentary rocks. Plate Tectonics: Carbonate are rocks “recycled” into Earth’s mantle via tectonic activity 10 5 9/13/24 Carbon Dioxide Concentrations over the last 800Kyr Homo sapiens 11 Carbon Dioxide Greenhouse Gasses: “Trap” energy in lower atmosphere Anthropogenic: Caused by human activity Greenhouse gasses are increasing Charles Keeling 12 6 9/13/24 https://www.globalcarbonproject.org/carbonbudget/index.htm 13 2021 Global Carbon Budget (Atmosphere) NOTE: To convert GtCO2 to GtC multiply by 12/44 (the ratio of atomic weights) To convert GtC to ppm, divide by 2.13 (explanation is a little more involved) Sources (Gt CO2 per yr): Sinks (Gt CO2 per yr): Land: +500 Land: +511 Land Use: +5 Ocean: +290 Ocean: +300 Volcanoes: (small, ~0.4) Fossil Fuels: +35 TOTAL: +830 TOTAL: 811 ATMOSPHERE GAINS 19 GtCO2 PER YEAR è CONCENRATION INCREASES 14 7 9/13/24 Learning Objectives Describe some major features of the global carbon cycle Explain the difference between a reservoir of carbon, and a flux of carbon. How do they relate to each other? Describe where anthropogenic sources of carbon dioxide are coming from, both regionally and via sectors. Describe some possible “solutions” for reducing greenhouse gas emissions 15 CO2 concentration: Historical contributions Since 1850, coal, oil, and gas have contributed about 220 ppmv to CO2 concentration. Land use has contributed another 103 ppmv. The ocean and land have absorbed about 60% of that. About 40% remains in the atmosphere. 16 8 9/13/24 17 Source of Information: https://www.globalcarbonproject.org/ Anthropogenic carbon dioxide emissions (source) exceed the ocean and land sinks for carbon dioxide. And, emissions are increasing each year. Carbon Dioxide Concentration Fossil CO2 Emissions 18 9 9/13/24 How have emissions evolved through time? Most of historical emissions have come from coal and oil. These sources are not increasing (but still positive sources!) 19 Where do we get our energy (Globally)? Fossil fuels (coal, oil, gas) have, and still do, dominate energy production globaly. Growth: Gas (linear growth), Renewables (exponential growth) 20 10 9/13/24 Regional CO2 Emissions: Total global emissions are increasing each year. Emissions in the USA and Europe are decreasing, while increases in China, India, and the rest of the world are increasing. BUT… 21 Regional CO2 Emissions per person: Historically, the USA and Europe have had some of the highest emissions per person. 22 11 9/13/24 Where do we get our energy in the US? 70-80% of energy still comes from fossil fuel sources. Coal use is decreasing rapidly, but natural gas is increasing (market driven). Renewable energy now supplies about 8% of our energy, and is growing rapidly. 23 How much more can we emit, in total? Answer depends on how much warming we are willing to accept. 24 12 9/13/24 What do emissions look like? Future emissions determine future warming. Ultimately, though, emissions (source) need to decrease rapidly, and sinks (including geoengineering?) need to increase to reduce expected climate change. 25 Learning Objectives Describe some major features of the global carbon cycle Explain the difference between a reservoir of carbon, and a flux of carbon. How do they relate to each other? Describe where anthropogenic sources of carbon dioxide are coming from, both regionally and via sectors. Describe some possible “solutions” for reducing greenhouse gas emissions 26 13 9/13/24 27 28 14 9/13/24 Solutions: There are many, many solutions that are available now, and more will be available as technology develops No one solution solves the problem. No ten solutions solve the problem. There are a LOT of solutions that are needed è GOOD NEWS! Everyone can do SOMETHING Future warming depends on future concentration. There are many emissions pathways to the same future concentrations 29 15 9/16/24 ATM OCN 100 / 101 Week 3: Energy in the Atmosphere Energy, Temperature, and the First Law of Thermodynamics The Second Law of Thermodynamics: Applications in our Atmosphere Application: Latent Heat and Hurricanes 1 Learning Objectives Identify “forms of energy” in everyday situations Describe the difference between Internal Energy and Temperature Distinguish between heat capacity and specific heat Apply the First Law of Thermodynamics to specific examples Describe ways in which energy can be transferred 2 Energy Definitions: Force: Some action that can influence the motion of an object Work: is done when a force causes an object to move (equals force times distance) Energy: “The ability to do work”. Units: 1 Joule = 1 N m = 1 kg m2/s2 1 Calorie = 4.184 J (1 Cal = 1 kcal = 4186J) 3 1 9/16/24 Forms of Energy Potential Energy: The Potential to do work 4 Forms of Energy Potential Energy: The Potential to do work 5 Forms of Energy Kinetic Energy: Energy of Motion 6 2 9/16/24 Internal Energy: “Heat” Definition: Internal Energy Total kinetic energy produced by random motions of molecules and atoms “Energy of random molecular motion” (Related to Temperature, structure, and total mass of a substance) 7 Temperature: Temperature: Measures the average kinetic energy of molecule in a substance (related to average molecular speed (~500 m/s at room temperature) Which has the higher temperature – Lake Mendota or my coffee? Which has more internal energy – Lake Mendota or my coffee? 8 Ground Temp. Obs. (Not Verified) A typical September 93.9C, Death Valley 70.7C, Lut Desert, high temperature in … Iran Air Temp. Obs. Miami 56.7C, Death Valley Madison 10 July, 1913 54.4C, Death Valley Barrow, AK 54.4C, Kuwait South Pole Station 9 3 9/16/24 Learning Objectives Identify “forms of energy” in everyday situations Describe the difference between Internal Energy and Temperature Distinguish between heat capacity and specific heat Apply the First Law of Thermodynamics to specific examples Water and sand warming up on a hot afternoon Why does air get colder as it rises? 10 Heat Capacity: Definition: Heat Capacity: Amount of heat needed to raise the temperature of a substance by 1°C Þ Proportional to mass Þ Depends (somewhat) on composition Application: Which has the higher heat capacity: Lake Mendota or a cup of coffee? If the same amount of energy is added, which would warm more? 11 Specific Heat: Problem: It’s hard to compare energy requirements between objects that have different mass. Definition: Specific Heat: Amount of heat needed to raise the temperature of 1g of an object by 1°C Þ Depends on particular properties of a substance Þ NOT proportional to mass! Note: Total Heat Capacity = Specific Heat x Mass 12 4 9/16/24 Specific Heat: Specific Heat: Amount of heat needed to raise the temperature of 1g of an object by 1°C Þ NOT proportional to mass! Cheese: 2770 Tomato Sauce: 3980 13 Learning Objectives Identify “forms of energy” in everyday situations Describe the difference between Internal Energy and Temperature Distinguish between heat capacity and specific heat Apply the First Law of Thermodynamics to specific examples Water and sand warming up on a hot afternoon Why does air get colder as it rises? 14 Conservation of Energy Concept: Conservation of Energy: Energy cannot be created or destroyed - it can only change forms 15 5 9/16/24 First Law of Thermodynamics (Simply a statement of energy conservation) First Law of Thermodynamics: Change in Heat Work done Internal = added to — by system Energy system Change in Internal Energy = Mass * Specific Heat * Temp. Change 16 Application: Why is beach sand so hot on a sunny day, but the water stays cool? First Law of Thermodynamics: ΔE = Q - W Change in Work Heat internal = added - done by energy system 17 Application: Why is beach sand so hot on a sunny day, but the water stays cool? First Law of Thermodynamics: ΔE = Q - W Change in Work Heat internal = added - done by energy system 18 6 9/16/24 Application: Why is beach sand so hot on a sunny day, but the water stays cool? The same amount of energy is being added to both the sand and the water. So, the change in internal energy is the same for both. BUT… Change in Work Heat internal = added - done by energy system 19 Application: Why is beach sand so hot on a sunny day, but the water stays cool? Mass * Spec. Heat * Temp. Change = Change in Int. Energy = Heat Added Sand: Water: Sun’s energy absorbed in Sun’s energy absorbed in ~1cm of sand ~10m of water Þ Small total mass Þ Large total mass Þ Small specific heat Þ Large specific heat Þ Small total heat capacity Þ Large total heat capacity Þ Large temperature Þ Small temperature change change 20 Heat Added: Change in Internal Energy Solar Radiation Temperature 0 21 7 9/16/24 Application: Warming up Lake Mendota How much should Lake Mendota warm up in 8hr, assuming it absorbs energy at a rate of 500 W/m2? 500 Energy flux: 500 W / m2 Lake Mendota average depth: 13m Specific Heat of Water: 4186 J / kg / oC Density of Water: 1000 kg / m3 22 Application: Warming up Lake Mendota Step 1: Set up budget equation, terms: Change in Heat Work Internal = added to — done by 500 Energy system system 23 Application: Warming up Lake Mendota Step 2: Identify total amount of heat added 500 24 8 9/16/24 Application: Warming up Lake Mendota Step 3: Plug in numbers and rearrange to get temperature change 500 25 Example (on your own): Let’s plug in some numbers! Assume 500 Joules per second from the sun 1 m2 Water: Density: ~1000 kg/m3 Volume: 10 m2 Specific Heat: 4186 J/C/kg Step 1: Change in Internal Energy = Heat Added – Work Done ç No work done Step 2: Total Heat Added = 1m 2 * 500 J/(m 2s) * 3600 s/hr * 8hr = 14,400,000 J Step 3: Convert Change in Internal Energy to Temperature Change: Change in Internal Energy = Mass * Specific Heat * Temperature Change Change in Internal Energy = Volume * Density * Specific Heat * Temperature Change 14,400,000 J = (1m 2 * 10 m) * 1,000 kg/m 3 * 4,186 J/(kg oC) * Temperature Change è Temperature Change = 14,400,000 J/m 2 / (10,000 kg * 4,186 J/(kg oC) ) = 0.34 oC 26 Example (on your own): Let’s plug in some numbers! Assume 500 Joules per second from the sun 1 m2 Sand: Density: ~1500 kg/m3 Volume: 0.01 m2 Specific Heat: 795 J/(kg oC) Step 1: Change in Internal Energy = Heat Added – Work Done ç No work done Step 2: Total Heat Added = 1m 2 * 500 J/(m 2s) * 3600 s/hr * 8hr = 14,400,000 J Step 3: Convert Change in Internal Energy to Temperature Change: Change in Internal Energy = Mass * Specific Heat * Temperature Change Change in Internal Energy = Volume * Density * Specific Heat * Temperature Change 14,400,000 J = (1m 2 * 0.01 m) * 1,500 kg/m 3 * 795 J/(kg oC) * Temperature Change è Temperature Change = 14,400,000 J/m 2 / (15 kg * 795 J/(kg oC) ) = 1,207 oC … Wait… that’s too hot. W hat’s going on here? We’ll have to wait until we learn the SECOND LAW OF THERMODYNAMICS! 27 9 9/16/24 First Law of Thermodynamics Application: Why does temperature decrease with altitude? First Law of Thermodynamics: ΔE = Q - W Change in Work Heat internal = added - done by energy system Definition: Adiabatic: No heat added to system 28 Application: Why does temperature decrease with altitude? Consider: A dry parcel of air, that HEIGHT (m) rises adiabatically (i) Parcel has the same pressure and temperature (20°C) as it’s environment Temperature (°C) 29 Consider: A dry parcel of air, that rises adiabatically HEIGHT (m) (i) Parcel has the same pressure and temperature (20°C) as it’s environment Temperature (°C) 30 10 9/16/24 Consider: A dry parcel of air, that (ii) Suppose the rises adiabatically parcel rises 1000m => environmental pressure decreases HEIGHT (m) (i) Parcel has the same pressure and temperature (20°C) as it’s environment Temperature (°C) 31 (iii) Air in parcel pushes outward to (ii) Suppose the equilibrate with parcel rises 1000m environmental => environmental pressure => It does pressure decreases HEIGHT (m) Work!!! Internal energy decreases, temperature drops to 10°C (i) Parcel has the same pressure and temperature (20°C) Consider: A dry as it’s environment parcel of air, that rises adiabatically Temperature (°C) 32 Dry Adiabatic Lapse Rate: Concept: The Dry 10°C per 1000m HEIGHT (m) Adiabatic Lapse Rate As an unsaturated parcel of air rises, it cools at the Dry Adiabatic Lapse Rate, Or 10°C per 1000m Temperature (°C) 33 11 9/16/24 Example 2: Why does temperature decrease with altitude? ΔE = Q - W 34 Learning Objectives Identify “forms of energy” in everyday situations Describe the difference between Internal Energy and Temperature Distinguish between heat capacity and specific heat Apply the First Law of Thermodynamics to specific examples Water and sand warming up on a hot afternoon Why does air get colder as it rises? 35 12 9/18/24 ATM OCN 100 / 101 Week 3: Energy in the Atmosphere Energy, Temperature, and the First Law of Thermodynamics The Second Law of Thermodynamics: Applications in our Atmosphere Application: Latent Heat and Hurricanes 1 Learning Objectives Describe different ways that energy is transferred in our atmosphere and climate system Explain how phase changes of water can affect the internal energy of the environment that is interacting with that water Describe the spatial structure of a hurricane Explain how heat transfer between the ocean and atmosphere provides energy for hurricanes 2 1 9/18/24 Concept: Second Law of Thermodynamics WARM COLD HEAT TRANSFER If two objects with different temperatures are “in contact”, heat will transfer from a warm object to a cold object. 3 Modes of Heat Transfer Definitions: Conduction: molecule to molecule / direct contact Convection: transfer by buoyant fluid transport (usually vertical transport) Advection: transfer by horizontal fluid transport Latent Heat: phase change Radiation: transfer by electromagnetic radiation 4 2 9/18/24 Heat Transfer in the Atmosphere Radiation: Ultimate source of energy for the Earth system. Also, Earth loses energy to space via radiation Conduction: A THIN layer of air in contact with the ground transfers energy with the ground via conduction Latent Heat: evaporation from the oceans and land transfers heat to the atmosphere (when water condenses) Convection: Heat is moved upward via rising plumes of air 5 Conduction 6 3 9/18/24 Pacific Northwest Heat Wave 7 Conduction VERY closely confined to the ground… Why? Air is a very poor conductor, in general. So conduction only affects a thin layer near the surface. BUT, once the air in that thin layer heats up, it is transferred upward via convection. 8 4 9/18/24 Surface inversions: Air near the surface is colder than air just above the surface 9 Surface inversions: Land cools more rapidly than air (we’ll get to this). Energy transfer to land from air via conduction (thin layer) Low wind è no vertical mixing, so cold air stays trapped near surface Tend to occur on cold, clear nights 10 5 9/18/24 Heat Transfer: Convection: Heat transfer via fluid motion (hot air rises, cold air sinks) Buoyant plumes are called “thermals” If most buoyant air is already on top, convection does not occur (stable situation) 11 Heat Transfer: Advection: Heat transfer via horizontal fluid motion 12 6 9/18/24 13 Learning Objectives Describe different ways that energy is transferred in our atmosphere and climate system Explain how phase changes of water can affect the internal energy of the environment that is interacting with that water Describe the spatial structure of a hurricane Explain how heat transfer between the ocean and atmosphere provides energy for hurricanes 14 7 9/18/24 Latent Heat: Definition: Latent heat is the heat required (or released) for a substance to change phase. Add Heat è Substance switches to “less ordered” state Remove Heat è Substance switches to “more ordered” state Latent Heat of Vaporization, H2O: Lv = 2.25x106 J/kg Lv = 2,250,000 J/kg Latent Heat of Fusion, H2O: Lf = 3.34x105 J/kg Lf = 334,000 J/kg 15 Latent Heat: Heat required for a substance to change phase Examples: Evaporation takes energy from the environment to convert liquid to vapor. à Boiling water stays at 100oC even though heat is added à You feel cold when stepping out of a shower à Rain falls, evaporates into a dry layer and the air cools 16 8 9/18/24 Latent Heat: Heat required for a substance to change phase Examples: Condensation “releases” energy to the environment as vapor condenses to liquid. à Steam burns à Steam heat (what we use around campus!) à Condensation in thunderstorms provides a source of energy 17 Example: Raindrop evaporates in dry air Raindrop falls through dry air, starts to evaporate Energy is required to change phase from liquid to vapor That energy comes from the internal energy in the system (think temperature) Air is colder after the raindrop evaporates (Same process for stepping out of a swimming pool or shower è you feel colder!) 18 9 9/18/24 Example: Vapor condenses into cloud droplets Water vapor condenses into raindrops as clouds form Latent heat is released as vapor condenses That energy adds to the internal energy in the system (think temperature) Air is warmer after condensation occurs (Same process for a steam burn!) 19 Latent Heat: Why is it important? Weather: Condensation is a source of energy for rising Climate: source of heat air in clouds for higher latitudes 20 10 9/18/24 Learning Objectives Describe different ways that energy is transferred in our atmosphere and climate system Explain how phase changes of water can affect the internal energy of the environment that is interacting with that water Describe the spatial structure of a hurricane Explain how heat transfer between the ocean and atmosphere provides energy for hurricanes 21 What is the life cycle of a hurricane? Tropical Disturbance: disorganized clump of thunderstorms, often associated with the trough of a wave in the easterlies 22 11 9/18/24 What is the life cycle of a hurricane? Tropical Depression: a disturbance with a weak low-pressure center of about 1010 mb, cyclonic rotation of winds, wind speed less than 35kt. A tropical depression gets a number, but not yet a name 23 What is the life cycle of a hurricane? Tropical Storm: When sustained winds reach 35kt, a disturbance is classified as a tropical storm, and the storm is given a name 24 12 9/18/24 What is the life cycle of a hurricane? Hurricane: When sustained winds are 65kt or greater, the system is classified as a hurricane. A “major hurricane” (Cat 3-5) has sustained winds greater than or equal to 110kt 25 What is inside hurricane? At the center of low pressure is the eye, 8 to 80 km across, often almost entirely clear of clouds (sinking air) Surrounding the eye is an eye wall, a narrow, circular, rotating region of intense thunderstorms and strong upward motion Spiral bands of thunderstorms and cumulus clouds extend outwards from the eye wall. 26 13 9/18/24 Identify: Eye Eyewall Spiral rainband Clear air rainband 27 Identify: Eye Eyewall Spiral rainband Clear air rainband 28 14 9/18/24 Learning Objectives Describe different ways that energy is transferred in our atmosphere and climate system Explain how phase changes of water can affect the internal energy of the environment that is interacting with that water Describe the spatial structure of a hurricane Explain how heat transfer between the ocean and atmosphere provides energy for hurricanes 29 Latent Heat: Why is it important? Source of energy for hurricanes 1. Water (vapor) evaporates from warm ocean surface à Transfer of LATENT energy from ocean to atmosphere 30 15 9/18/24 Latent Heat: Why is it important? 2. Water vapor condenses (latent heat release) into clouds / rain à LATENT energy converted to INTERNAL energy, which warms and “expands” the atmosphere (creates pressure differences) 31 Latent Heat: Why is it important? 3. Atmosphere “does work” by converting pressure differences into kinetic energy à Atmospheric thermal energy radiated to space, and kinetic energy is dissipated by friction 32 16 9/18/24 Hurricane Katrina Path 33 Learning Objectives Describe different ways that energy is transferred in our atmosphere and climate system Explain how phase changes of water can affect the internal energy of the environment that is interacting with that water Describe the spatial structure of a hurricane Explain how heat transfer between the ocean and atmosphere provides energy for hurricanes 34 17 9/20/24 ATM OCN 100 / 101 Week 3: Energy in the Atmosphere Energy, Temperature, and the First Law of Thermodynamics The Second Law of Thermodynamics: Applications in our Atmosphere Application: Latent Heat and Hurricanes 1 Learning Objectives Explain how phase changes of water can affect the internal energy of the environment that is interacting with that water Describe the spatial structure of a hurricane, and climatological characteristics of the hurricane season Explain how heat transfer between the ocean and atmosphere provides energy for hurricanes Describe impacts of wind, storm surge, and rainfall associated with tropical cyclones 2 Latent Heat: Definition: Latent heat is the heat required (or released) for a substance to change phase. Add Heat è Substance switches to “less ordered” state Remove Heat è Substance switches to “more ordered” state Latent Heat of Vaporization, H2O: Lv = 2.25x106 J/kg Lv = 2,250,000 J/kg Latent Heat of Fusion, H2O: Lf = 3.34x105 J/kg Lf = 334,000 J/kg 3 1 9/20/24 Latent Heat: Heat required for a substance to change phase Examples: Evaporation takes energy from the environment to convert liquid to vapor. à Boiling water stays at 100 oC even though heat is added à You feel cold when stepping out of a shower à Rain falls, evaporates into a dry layer and the air cools 4 Latent Heat: Heat required for a substance to change phase Examples: Condensation “releases” energy to the environment as vapor condenses to liquid. à Steam burns à Steam heat (what we use around campus!) à Condensation in thunderstorms provides a source of energy 5 Example: Vapor condenses into cloud droplets Water vapor condenses into raindrops as clouds form Latent heat is released as vapor condenses That energy adds to the internal energy in the system (think temperature) Air is warmer after condensation occurs (Same process for a steam burn!) 6 2 9/20/24 Latent Heat: Why is it important? Weather: Condensation is a source of energy for rising Climate: source of heat air in clouds for higher latitudes 7 Learning Objectives Explain how phase changes of water can affect the internal energy of the environment that is interacting with that water Describe the spatial structure of a hurricane, and climatological characteristics of the hurricane season Explain how heat transfer between the ocean and atmosphere provides energy for hurricanes Describe impacts of wind, storm surge, and rainfall associated with tropical cyclones 8 What are Tropical Cyclones? Large (~200-1000km), long-lived (several days) circulating storms that have a closed circulation around a well- defined center Wind Speeds: Tropical Depression: < 35 kt Tropical Storm: 35-64 kt Hurricane (Atlantic): > 65 kt Hurricane Katrina, August 27, 2005 9 3 9/20/24 Where do Tropical Cyclones form? 10 11 What is the life cycle of a hurricane? Tropical Disturbance: disorganized clump of thunderstorms, often associated with the trough of a wave in the easterlies 12 4 9/20/24 What is the life cycle of a hurricane? Tropical Depression: a disturbance with a weak low-pressure center of about 1010 mb, cyclonic rotation of winds, wind speed less than 35kt. A tropical depression gets a number, but not yet a name 13 What is the life cycle of a hurricane? Tropical Storm: When sustained winds reach 35kt, a disturbance is classified as a tropical storm, and the storm is given a name 14 What is the life cycle of a hurricane? Hurricane: When sustained winds are 65kt or greater, the system is classified as a hurricane. A “major hurricane” (Cat 3-5) has sustained winds greater than or equal to 110kt 15 5 9/20/24 What is inside hurricane? At the center of low pressure is the eye, 8 to 80 km across, often almost entirely clear of clouds (sinking air) Surrounding the eye is an eye wall, a narrow, circular, rotating region of intense thunderstorms and strong upward motion Spiral bands of thunderstorms and cumulus clouds extend outwards from the eye wall. 16 Identify: Eye Eyewall Spiral rainband Clear air rainband 17 Identify: Eye Eyewall Spiral rainband Clear air rainband 18 6 9/20/24 FIGURE 8-22: Photograph of the eye wall of Hurricane Katrina south of Louisiana landfall on August 28, 2005 taken from a “hurricane hunter” aircraft..(Photographe r: Lieutenant Mike Silah, NOAA Corps, NOAA AOC.) 19 Flight through Tropical Storm Idalia on NOAA WP- 3D Orion N43RF Miss Piggy on August 28, 2023. https://www.omao.noaa.gov/aircraft-operations/noaa-hurricane-hunters 20 Lt. Cm dr. Rebecca Waddington and Capt. Kristie Twining aboard NOAA's Gulfstream IV-SP during a hurricane surveillance flight on August 5, 2018. https://www.om ao.noaa.gov/ 21 7 9/20/24 Learning Objectives Explain how phase changes of water can affect the internal energy of the environment that is interacting with that water Describe the spatial structure of a hurricane, and climatological characteristics of the hurricane season Explain how heat transfer between the ocean and atmosphere provides energy for hurricanes Describe impacts of wind, storm surge, and rainfall associated with tropical cyclones 22 Latent Heat: Why is it important? Source of energy for hurricanes 1. Water (vapor) evaporates from warm ocean surface à Transfer of LATENT energy from ocean to atmosphere 23 Latent Heat: Why is it important? 2. Water vapor condenses (latent heat release) into clouds / rain à LATENT energy converted to INTERNAL energy, which warms and “expands” the atmosphere (creates pressure differences è Potential Energy) 24 8 9/20/24 Latent Heat: Why is it important? 3. Atmosphere “does work” by converting potential energy into kinetic energy à Atmospheric thermal energy radiated to space, and kinetic energy is dissipated by friction 25 Hurricane Katrina Path 26 Learning Objectives Explain how phase changes of water can affect the internal energy of the environment that is interacting with that water Describe the spatial structure of a hurricane, and climatological characte