NATS 101 Intro to Weather and Climate Section 06: 12:30PM TTh ILC 150 Dr. E. Robert Kursinski TA: Nathan Johnson Please turn off cell phones

Lecture 1-Nats 1012 Who Am I? Professor Department of Atmospheric Science Joint Faculty Appointment Dept. of Planetary Sciences Worked for many years at NASA JPL in So. Cal. Research Specialty Remote Sensing, Water cycle, Planetary atmospheres Ph.D. in Planetary Sciences M.S. in Electrical Engineering B.S. in Physics, Minor in Music Theory

Lecture 1-Nats 1013 Vital Statistics Office Hours: Dr. Kursinski W 2:00-3:00 pm PAS Bldg, Rm 580 and by Appointment Mr. Johnson MWF 1:00-2:00 pm PAS Bldg, Rm 526 and by Appointment Required Text: Essentials of Meteorology-An Invitation to the Atmosphere, 4 rd Ed. by C. Donald Ahrens Picture Link Publisher Download, Save $Picture LinkPublisher Download, Save $ Recommended Text: Study Guide for Essentials of Meteorology, 4 rd Ed. by C. Donald Ahrens LinkLink Required Material: Thirty (30) 4''x 6'' index cards.

Lecture 1-Nats 1014 Course Description Introduction to the science of weather processes and climate change: atmospheric structure and composition, energy balance, clouds and precipitation, wind systems, weather fronts, cyclones, weather forecasting, thunderstorms and lightning, hurricanes, monsoons, ozone hole, air pollution, climate and global warming and optical phenomena. The new Global Climate Change lecture series website is up:

Lecture 1-Nats 1015 Course Description Emphasis will be given to phenomena that have strong impacts on human activities. The fundamental importance of physics, chemistry and mathematics will be noted. Atmospheric Science is a branch of Applied Physics

Lecture 1-Nats 1016 Attendance Policy Attendance is mandatory, and will be tallied throughout the term. After three unexcused absences prior to week 9, I will submit to the Office of Curriculum and Registration an administrative drop from the course and assign a grade in accordance with UA policy.

Lecture 1-Nats 1017 Student Behavior UA Code of Academic Integrity, Code of Conduct and Student Code of Conduct are enforced in this course. Every student is responsible for learning these codes and abiding by them. Students can submit complaints online at

Lecture 1-Nats 1018 Grading Policy Final grade will be based on scores from closed book/closed notes quizzes and final exam. Quizzes will consist of multiple choice questions and short answer questions. Quizzes will cover new material presented through the end of the previous lecture day. Extra credit questions given on some quizzes. Extra credit impromptu “pop” quizzes given.

Lecture 1-Nats 1019 Grading Policy There will be seven quizzes during the term. Dates for the quizzes are listed on the home page. Students who arrive late on quiz days will be not allowed to take the quiz after the first student turns in her/his quiz. No Exceptions The lowest score among the seven quizzes will be excluded from the course grade. Therefore, no make-up quizzes.

Lecture 1-Nats Grading Policy If your final exam score exceeds the average of your 6 best quizzes, the quizzes will comprise 60% of your term grade and the final 40%. Otherwise, the quizzes will comprise 75% of your term grade and the final 25%. CARROT:CARROT: If your average is 90% or higher on all 7 quizzes, you will earn an exemption from the final and will receive an "A'' for the course. No Extra Credit Projects. No Exceptions. So Plan Accordingly!

Lecture 1-Nats Final Examination Section 06 (12:30 am TTh): ILC 150 Thursday Dec. 14, 11:00 am - 1:00 pm The final will consist of approximately 60 multiple choice questions and short answer questions. A number of questions will be taken verbatim from the old quizzes.

Lecture 1-Nats Course Grading Course Grading Scale A 90% or higher B % C % D % E< 55.0%

Lecture 1-Nats Expectations Every student is expected to: Complete all of the assigned reading before the lecture (unless you hear otherwise). Devote a minimum of 2 hours outside of class studying, reading, etc. for every hour of classroom lecture. Unit Credit DefinitionUnit Credit Definition dismissedAttend class daily, arrive on time, leave when class is dismissed (courtesy to peer students).

Lecture 1-Nats The Golden Rule Instructor and students all show: Mutual Respect!

Lecture 1-Nats Literacy Requirements Although the writing requirement for this course is negligible, there is a science literacy requirement: Use scientific notation for writing numbers (especially rather large or small ones). Specify units of physical quantities (e.g. meters for elevation, etc.). Attempt to quantify physical relationships.

Lecture 1-Nats Announcements Course Homepage…is now functional Click Students and Courses Click Course Links Click NATS101 – Kursinski User Name: nats101-6 (if established) Password: fall2006 (if established)

Lecture 1-Nats Class Format: Lecture Days 2-4 minutes - Interesting weather discussion 2-3 minutes - Review/Summary/Clean-up From Prior Lecture, Optional minutes - New Material Lecture, Demos, Discussion 2-3 minutes - Wrap-up and Summary

Lecture 1-Nats Class Format: Quiz Days 2-3 minutes - Review/Summary/Clean-up From Prior Lecture, Optional 30 minutes - Lecture 10 minutes - Last Minute Questions Passing Out Quiz Materials 30 minutes - Quiz

Lecture 1-Nats Class LISTSERV Use for any questions, comments, discussions that are general interest to the class. is reserved for personal requests not of general To subscribe go to and click the link “Subscribe to a list” Follow straightforward instructions

Lecture 1-Nats LISTSERV You can subscribe by sending an to with the following as the only line in the body of the subscribe xxxxxx Firstname Lastname Substitute the list you want to join for xxxxxx, i.e. Substitute your first name for Firstname Substitute your last name for

Lecture 1-Nats Importance of Atmosphere Necessary for a wide spectrum of features Oceans Clouds, Rain, Fresh Water Erosion by Water and Wind Life, Life on Land Blue Skies, Red Sunsets, Twilight Sound

Lecture 1-Nats Importance of Atmosphere Point 1- Offers Protection Consider surface temperatures Without atmosphere? 0 o F global average, large diurnal swings Similar to the Moon’s Climate With atmosphere… 60 o F global average, moderate diurnal swings

Lecture 1-Nats Importance of Atmosphere Point 2 - Offers Protection Consider Surface Radiation Shields against harmful UV radiation

Lecture 1-Nats Importance of Atmosphere Consider Survival Time Without Food  few weeks Without Water  few days Without Air  few minutes

Lecture 1-Nats To Understand the Atmosphere Examine its interfaces with land/ocean with space Sun Space Earth Atmosphere 13,000 km Is a very thin skin 99% below 50 km (31 miles) 50% below 5.5 km (3.4 miles) Atmosphere Picture Energy Flow Solar Input = Output to Space

Lecture 1-Nats NASA photo gallery Note “thinness” of atmosphere in light blue

Lecture 1-Nats Example of Ocean-Atmosphere Coupling: El Nino-La Nina

Lecture 1-Nats

Lecture 1-Nats 10129

Lecture 1-Nats Local Weather and Climate: The North American Monsoon Tucson gets half of its rainfall during the summer Sonora, Mexico gets most of its rainfall during the summer During summer, high pressure sets up to the east/northeast of Arizona which brings moisture in from the south The monsoon is still going: Thunderstorms yesterday For a monsoon overview and daily forecast, see:

Lecture 1-Nats July minus June Rainfall Douglas et al (1993)

Lecture 1-Nats Local: Recent Monsoon Rainfall Record water flow through the Sabino and Rillito Creeks on July 31 Rillito flow higher than Colorado river! See

Lecture 1-Nats Course Building Blocks Intro  1 st week or so Energy  ~2 weeks Moisture  ~2 weeks Dynamics  ~3 weeks Above are interdependent Specific Topics  ~6 weeks

Lecture 1-Nats Atmospheric Composition Permanent Gases N 2 and O 2 are most abundant gases Percentages hold constant up to 80 km Ar, Ne, He, and Xe are chemically inert N 2 and O 2 are chemically active, removed & returned Ahrens, Table 1.1, 4 th Ed.

Lecture 1-Nats N 2 Boiling point: 77 °K or -196°C or –320 °F O 2 Boiling point: 90 °K or -183 °C or -297 °F N 2 and O 2 Balance between input (production) and output (destruction): Input:plant/animal decaying Output: soil bacteria; oceanic plankton-->nutrients Input:plant photosynthesis Output: organic matter decay chemical combination (oxidation) breathing

Lecture 1-Nats Atmospheric Composition Important Trace Gases Ahrens, Table 1.1, 3 rd ed. Which of these is now wrong even in the 4th edition of Ahrens?

Lecture 1-Nats Sources vegetative decay volcanic eruptions animal exhalation combustion of fossil fuels (CH O 2 > 2 H 2 O + CO 2 ) Sinks photosynthesis (oxygen production) dissolves in water phytoplankton absorption (limestone formation) Carbon Dioxide CO 2

Lecture 1-Nats CO 2 Trend “Keeling Curve” Some gases vary by season and over many years. The CO2 trend is the cause for concern about global warming. CO 2 increases in northern spring, decreases in northern fall See

Lecture 1-Nats H 2 O Vapor Variability Precipitable Water (mm) Some gases can vary spatially and daily

Lecture 1-Nats Aerosols 1 cm 3 of air can contain as many as 200,000 non-gaseous particles. –dust –dirt (soil) –ocean spray –volcanic ash –water –pollen –pollutants

Lecture 1-Nats Aerosols - Volcanic Ash Fig. 1-4, p.6

Lecture 1-Nats Aerosols - Dust Particles Dust Storm on Interstate 10, between Phoenix and Tucson, AZ.

Lecture 1-Nats Aerosols Provide condensation nuclei for water vapor. Provide a surface area or catalyst needed for much atmospheric chemistry. Aerosols can deplete stratospheric ozone. They can also cool the planet by reflecting sunlight back to space.

Lecture 1-Nats Two Important Concepts Let’s introduce two new concepts... Density Pressure

Lecture 1-Nats What is Density? Density (  ) = Mass (M) per unit Volume (V)  = M/V  = Greek letter “rho” Typical Units: kg/m 3, gm/cm 3 Mass = # molecules (mole)  molecular weight (gm/mole) Avogadro number (6.023x10 23 molecules/mole)

Lecture 1-Nats Density Change Density (  ) changes by altering either a) # molecules in a constant volume b) volume occupied by the same # molecules a b

Lecture 1-Nats What is Pressure? Pressure (p) = Force (F) per unit Area (A) Typical Units: pounds per square inch (psi), millibars (mb), inches Hg Average pressure at sea-level: 14.7 psi 1013 mb in. Hg

Lecture 1-Nats Pressure Can be thought of as weight of air above you. (Note that pressure acts in all directions!) So as elevation increases, pressure decreases. Higher elevation Less air above Lower pressure Lower elevation More air above Higher pressure Bottom Top

Lecture 1-Nats Density and Pressure Variation Key Points 1.Both decrease rapidly with height 2.Air is compressible, i.e. its density varies Ahrens, Fig. 1.5

Lecture 1-Nats Why rapid change with height? Consider a spring with 10 kg bricks on top of it compressible The spring compresses a little more with each addition of a brick. The spring is compressible. 10 kg

Lecture 1-Nats Why rapid change with height? Now consider several 10 kg springs piled on top of each other. Topmost spring compresses the least! Bottom spring compresses the most! The total mass above you decreases rapidly w/height.  mass

Lecture 1-Nats Why rapid change with height? Finally, consider piled-up parcels of air, each with the same # molecules. The bottom parcel is squished the most. Its density is the highest. Density decreases most rapidly at bottom.

Lecture 1-Nats Why rapid change with height? Each parcel has the same mass (i.e. same number of molecules), so the height of a parcel represents the same change in pressure  p. Thus, pressure must decrease most rapidly near the bottom. pppp pppp pppp pppp

Lecture 1-Nats A Thinning Atmosphere Bottom Top Lower density, Gradual drop Higher density Rapid decrease NASA photo gallery

Lecture 1-Nats Pressure Decreases Exponentially with Height Logarithmic Decrease For each 16 km increase in altitude, pressure drops by factor of km - 1 mb 32 km - 10 mb 16 km mb 0 km mb 100 mb 10 mb 1 mb 16 km 32 km 48 km Ahrens, Fig. 1.5

Lecture 1-Nats Exponential Variation Logarithmic Decrease For each 5.5 km height increase, pressure drops by factor of km mb 11 km mb 5.5 km mb 0 km mb

Lecture 1-Nats Reading Assignment Ahrens Pages 1-22; (Appendix A: Units etc.), (Appendix C: Weather chart symbols) Problems 1.2, 1.3, 1.10, 1.14, 1.17, 1.18, 1.20 (1.17  Chapter 1, Question 17) Don’t Forget the 4”x6” Index Cards