ESCI 106 – Weather and Climate Lecture 1 8-18-2011 Jennifer D. Small Weather Fact of the Day: August 18 2005: 27 tornadoes were documented in WI, thus establishing its record for the greatest number of tornadoes reported in a calendar day. Most were F0 or F1, but an F3 storm killed 1, and hurt 23 between Fitchburg and Rockdale. 4 other injuries were reported FOCUS Successful students focus on the work to be done. They are academically selfdisciplined, spending appropriate amounts of time studying. They come to class on time and prepared. They complete all assignments and turn them in on time. They finish their programs. ADVANCE Successful students advance by always improving. They embrace life-long learning. They understand that subject expertise requires a long-term commitment, and commit to ongoing development of thinking skills and learning skills. LINK UP Successful students link up to make connections with the academic community. They get involved. They get to know their professors and study in groups, surrounding themselves with focused students and mentors. They use college resources and programs to help them with their learning. COMPREHEND Successful students comprehend. They study for comprehension. They seek to understand course content rather than simply complete requirements. They ask questions to gain understanding, reflect on what they are learning as well as if they are learning. ORGANIZE Successful students organize a plan to succeed. They have an educational goal. They focus on their educational purposes, maintain a specific education plan, and choose classes with an intentional learning purpose in mind. They are well-organized to meet all of their commitments and to achieve their goals. NEW IDEAS Successful students nurture new ideas. They are curious. They seek out new ideas, perspectives, and skills. They transfer concepts to new contexts in order to solve problems. They integrate concepts and knowledge to form a greater personal understanding. How do you envision a scientist? Most will picture a white middle aged man White coat Chemistry equipment… Villians in movies Does this look familiar?? TEXT BOOK Tarbuck, E.J., and Lutgens, F.K, 2010, Textbook: The Atmosphere – An Introduction to Meteorology, 11th edition. Available from the bookstore. Reading Assignments! Should be completed BEFORE class!!!! Come prepared to discuss the material covered in each chapter! What topics will we cover?? Too many to list on one slide!! Tornadoes Thunderstorms Hurricanes Global Winds Energy Budget Natural Disasters Cloud Types and Formation What is Meteorology?? Meteorology is the scientific study of the atmosphere and atmospheric phenomena including weather and climate. Not just TV Weather People Researchers (NASA, NOAA) Private Companies (AccuWeather, Weather Channel) Academics (Universities, Colleges) Why do we study Meteorology?? Daily Weather – affects how we plan our days Severe Weather – causes damage, loss of life, loss of property (memorable) Includes, tornadoes, hurricanes, snow storms, floods, thunderstorms… and much more. Climate Change – How will weather and climate change in the future? Affects quality of life, water supplies, food supplies Did you know?? On average, ~150 people die each year in the US from floods and flash floods—more than any other natural disaster? Can you name any recent weather related natural disasters in the US or Globally? 2004 – Hurrican Ivan 2005 - Hurricane Katrina 2011 Tornadoes - Midwestern US 2011 Blizzards – East Coast Snow Storms Current heat wave in Central US (TX etc). Meteorology is a mathematical science! Scientific Quantities and SI Units Science has it’s own language Scientific Notation To make things easier when dealing with very large and very small numbers Significant Figures Accuracy and precision are important! LETS WORK THROUGH SOME EXAMPLES TOGETHER! Scientific Quantities and Units! Mass – kg Distance – m Time – s Energy – Joules, J = Nm = kg*m/s2 * m (Force times distance) Pressure – N/m2 = Pascale, Pa (Force divided by area) kg*m/s2 *1/m2 Temperature – K Force – Newton, N, kg*m/s2 (Mass times acceleration) Density (ρ) – kg/m3 (Mass per volume) Area – m2 Velocity – m/s (Distance per unit time) Volume – m3 Acceleration – m/s2 (change in velocity/change in time) Power – Watt = J/s (energy per time) Mole – 6.023*1023 Things Scientific Notation! 10000 = 1 x 104 1000 = 1 x 103 100 = 1 x 102 10 = 1 x 101 1 = 1 x 100 1/10 = 1 x 10-1 1/100 = 1 x 10-2 1/1000 = 1 x 10-3 1/10000 = 1 x 10-4 24327 = 2.4327 x 104 7354 = 7.354 x 103 482 = 4.82 x 102 89 = 8.9 x 101 0.32 = 3.2 x 10-1 0.053 = 5.3 x 10-2 0.0078 = 7.8 x 10-3 0.00044 = 4.4 x 10-4 Significant Figures! No more than 3 sig figs, usually 2000 2 x 103 has ONE sig fig 2000 2.0 x 103 has TWO sig fig RULES 1) Multiplication & Division Round the final result to the least number of significant figures of any ONE term…. See example 2) Addition & Subtraction Round the final result to the least number of decimal places, regardless of the significant figure of any one term…. See example Chapter 1 – Introduction to the Atmosphere Weather The state of the atmosphere at any given time Climate A description of aggregate weather conditions; the sum of all statistical weather information that helps describe a place or region “Climate is what you expect, but weather is what you get” Meteorology every day Our typical experience with meteorology is through TV, print and online weather forecasts Great resource: http://www.nws.gov/ National Weather Service Earth’s Spheres http://www.its-about-time.com/iesart/iesspheres.jpg The Geosphere Extends from the surface to the center of the Earth (6400 km, 4000 miles) The largest of the spheres Main components are the crust, mantle, core http://earth.rice.edu/mtpe/geo/geosphere/what_images/interior.jpg The Biosphere Includes all life on Earth Ocean life is concentrated near the surface (sun penetrating) Life land can survive a few meters underground and flying insects and birds up to 1 km above the surface Extraordinary life found near deep sea vents, hot springs, deep rocks, upper atmosphere Showing different biomes, forests, deserts, plankton… http://earth.rice.edu/mtpe/geo/geosphere/what_images/interior.jpg The Hydrosphere Evaporation from the ocean and Transpiration from plants Cloud formation via condensation Precipitation onto land and ocean Runoff and infiltration The Water Cycle http://earth.rice.edu/mtpe/geo/geosphere/what_images/interior.jpg The Atmosphere The life giving envelope of gases VERY THIN Provides air we breath Provides protection from damaging UV radiation from the Sun All the weather experiences takes place within it. The Layers of the Atmosphere NOT TO SCALE!!!! http://www.theozonehole.com/atmosphere.htm Evolution of the Atmosphere The Earth’s atmosphere is the product of a lengthy evolutionary process that began 4.6 billion years ago Solar winds swept away the Earth’s early Hydrogen (H) and helium (He) atmosphere Primeval Phase An atmosphere unfamiliar to us Modern Phase What we live in now Primeval Atmosphere Our Solar System, including the Earth is believed to have developed from the accretion of dust and gases The Earth grew by accretion as the planet swept up cosmic dust in its path and it was hit by meteorites. In time, volcanoes began to spew forth lava, ash and gases By 4.4 billion yrs ago the Earth’s gravitational field was strong enough to retain a thin gaseous envelope Primeval Atmosphere The principle source of atmospheric gases was OUTGASSING The release of gases from rock through volcanic eruptions and impact of meteorites Perhaps 85% of all outgassing took within a million years of the planet’s formation Primeval Atmosphere was mostly CO2, N2, H2O, little CH4, NH3 (ammonia), SO2, HCl. Radioactive decay of an isotope of potassium added argon. Free Oxygen (O or O2) was absent!!! Primeval Atmosphere The Primeval atmosphere was rich in CO2 and may have been 10-20 times denser! Computer models predict that the average temperature of the earth as 185-230F!! After 4 billion years, the Earth (rocks) cooled enough to allow water vapor to condense into clouds and rain. CO2 dissolves in water so the rain, and oceans, “washed out” some of the CO2… cooling the planet further. After life emerged, primarily photosynthetic bacteria (~2.5 billion yrs ago), emerged O2 began building up, since O2 is a product of photosynthesis (and removes CO2). Modern Atmospheric Composition 78% Nitrogen (N) – basically inert so it was able to build up in the atmosphere 21% Oxygen (O) 1% Argon (Ar) – also inert Carbon Dioxide (CO2) – from respiration, combustion, GHG Methane (CH4) – cows, wetlands, rice patties, low oxygen environments, GHG Ozone (O3) – in both the stratosphere (good) and troposphere (bad) Water (H2O) – 0-5% variable over the surface of the earth Hydrogen (H2) Helium (He) Carbon Monoxide (CO) Ammonia (NH3) Nitrogen Oxide (NO) Nitrous Oxide (N2O) Sulfur Dioxide (SO2) Nitrogen Dioxide (NO2) Particles – Aerosols, dust, smoke Atmospheric Composition Where did all the Nitrogen come from? The answer lies mostly in three facts: 1. nitrogen is volatile in most of its forms 2. it is unreactive with materials that make up the solid earth 3. it is very stable in the presence of solar radiation. Over geological time, it has built up in the atmosphere to a much greater extent than oxygen It is an important component of life on earth (Nitrogen Cycle) Nitrogen Cycle http://www.chemicool.com/el ements/nitrogen.html Atmospheric Composition Why is Argon Third? Argon is formed by radioactive decay within the earth and released into the atmosphere through volcanic activity. It is an inert (and nonradioactive) gas and does not react chemically, so it gradually accumulates in the atmosphere. After a few billion years' worth of volcanoes, it's now the third (or fourth, depending on the humidity) most common gas in the atmosphere. Fun Fact: Used in Neon Lights! Atmospheric Composition Where does the oxygen come from? The primary way in which the Earth generates oxygen for the atmosphere is through photoshynthesis Photosynthesis accounts for 98% of the world's atmospheric oxygen The breakup of water molecules by ultraviolet radiation composes the other 1-2%. Atmospheric Composition Carbon dioxide News worthy Global Climate Change CO2 is an efficient absorber of energy emitted by the sun! Present in minute amounts ~0.0387% or 387 ppm Proportion of CO2 is relatively constant over the earth Steadily increasing since the 1960s…. Keeling Curve We’ll talk more about later Atmospheric Composition Variable Components Water Vapor Varies from 0-4% by volume Clouds and precipitation Heats the atmosphere like CO2 Releases or absorbs energy when it changes states (gas-liquid-solid) Aerosols Tiny solid and liquid particles Dust, pollution, sea salt, ash, smoke, biogenic particles Ozone NEXT SLIDE! Atmospheric Composition Ozone (O3) Water Vapor Three Oxygen Molecules! Concentrated high above the surface (in the stratosphere) Protects us from UV rays from the sun (what gives us sun burns) We’ll go into detail later… Ozone Hole We’ll spend a whole lecture on this later… Predominantly found in the Antarctic Montreal Protocol – What happens when the scientists and politicians of the world come together. SUCCESS!!! Atmospheric Composition Extent of the Atmosphere No clear boundary at the upper atmosphere Rapidly thins as altitude increases Half the atmosphere lies below ~5.6 km (3.5 miles) Rate of pressure decrease is not constant Air is HIGHLY compressible Thermal Structure of the Atmosphere Troposphere – warmed by earth decreases with height Stratosphere – sun warms ozone, ozone warms the air, temperature increases with height Mesosphere – returns to normal temperature decrease with height Thermosphere – very high temperatures, the sun warms N2 and O2 and heats up the rarefied “air”. The molecules have lots of energy and that energy is not necessarily in ‘heat’ energy. Thus, the temperature is high due to the interactions of the energized molecules bumping into one another. Troposphere Name literally means the region where air “turns over” Where “Weather” happens Due to vertical and horizontal mixing of air Temperature decreases with height Environmental lapse rate 6.5 deg K per km 3.6 deg F per 100 ft Highly variable Inversions – when it’s reversed Decreases until ~12 km TROPOPAUSE! Is the main focus of meteorologists Often called the “weather sphere” Stratosphere Begins above the tropopause (12 km - ~50 km) Temperature remains the same from ~12-20 km Temperatures increase from the Stratopause until the Mesopause (~50km - ~80 km) Temperature INCREASES with height -60 C to ~ 0 C (-80 F to 32 F) Due to the presence of OZONE, which heats the layer Ozone absorbs solar radiation Maximum from 15-30 km We study this layer with Weather balloons High altitude aircraft Satellites Mesosphere COLDEST temperatures in the atmosphere are observed here ~80-90 km (Mesopause) -90 C (-130 F) Pressure is very low Is the least studied region Difficult to access by Aircraft, balloons and satellites Still learning more!! Noctilucent clouds occur here! Thermosphere Begins after the Mesosphere and has no well defined upper limit (~80 km and above) Temperature begins to increase with height again! Counter intuitive, yup Minute fraction of the mass Extremely high temps (1000 C) Temperature is defined as: Average speed at which molecules move Gases here move FAST in thermosphere Even though there are few of them… What if an astronaut exposed his hand? It would not feel hot, not enough particles! Ionosphere The Ionosphere Located between 80-400 km Overlaps with the Thermosphere Is an electrically charged layer An ion is a atomic-scale particle that carries an electric charge No influence on daily weather Important for long wave radio transmission since it reflects radio transmissions They travel in straight lines and bounce off the Ionosphere The ionosphere is also the site of Aurora – Pretty!! Auroras The Auroras Aurora borealis (northern lights) Aurora australis (southern lights) Closely correlated with solar-flare activity Geographic location (Earth’s magnetic poles) Appear in the night sky as overlapping curtains Bottom at 100 km (62 miles) Tops at 400 km (248 miles or higher) Triggered by the Solar Wind A stream of electrically charged particles Includes protons and electrons Earth’s magnetic field deflects that wind Magnetosphere (next slide) Collisions rip apart molecules and excite atoms. As atoms shift down from the excited states or combine with free electrons they emit radiation (part of which is the visible aurora) Magnetosphere The magnetopshere The region of the upper atmosphere encompassed by the Earth’s magnetic field Earth’s magnetic field deflects the solar wind Results in it’s characteristic teardrop shape surrounding the planet Problem Solving Refer to weather map from Weather.com from 8-16-11 Estimate the observed high temperatures in central New York State and central Texas Central NY: 64 F Central TX: 86 F Refer to weather map from Weather.com from 8-18-11 Where is the coldest area on the weather map? Where is the warmest? Northern Maine Death Valley, CA/West Arizona