Transcript Lecture 1
NATS 101 Intro to Weather and Climate
Section 06: 12:30PM TTh ILC 150
Dr. E. Robert Kursinski TA: Nathan Johnson
Who Am I?
• • • •
Professor Department of Atmospheric Science Joint Faculty Appointment Dept. of Planetary Sciences Research Specialty Remote Sensing, Water cycle Ph.D. in Planetary Sciences M.S. in Electrical Engineering B.S. in Physics, Minor in Music Theory
Lecture 1-Nats 101 2
Vital Statistics
• • • •
Office Hours
: Dr. Kursinski W 2:00-2:50 pm PAS Bldg, Rm 580 or by Appointment Mr. Johnson TBD PAS Bldg, Rm 526 or by Appointment
Required Text
:
Essentials of Meteorology-An Invitation to the Atmosphere, 4 rd Ed.
by C. Donald Ahrens Picture Link Publisher Download, Save $
Recommended Text
:
Study Guide for Essentials of Meteorology, 4 rd Ed.
by C. Donald Ahrens Link
Required Material
: Thirty (30) 4''x 6'' index cards.
Lecture 1-Nats 101 3
Course Description
Introduction to the science of weather processes and climate change: atmospheric structure and composition, energy balance, clouds and precipitation, wind systems, fronts, cyclones, weather forecasting, thunderstorms, lightning, hurricanes, ozone hole, air pollution, global warming and optical phenomena.
Lecture 1-Nats 101 4
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 Sciences Applied Physics Lecture 1-Nats 101 5
Attendance Policy
Attendance is mandatory, and I reserve the right to tally it 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.
http://catalog.arizona.edu/2005-06/policies/classatten.htm
Lecture 1-Nats 101 6
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.
http://w3.arizona.edu/~studpubs/policies/ppmainpg.html
Students can submit complaints online at http://web.arizona.edu/~dos/uapolicies/ Lecture 1-Nats 101 7
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 101 8
Grading Policy
• • •
There will be seven quizzes during the term.
Dates for the quizzes are
Jan 27, Feb 10, Feb 24, Mar 10, Mar 31, Apr 14, Apr 28.
No Exceptions 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 101 9
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: 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 101 10
Final Examination
Section 06 (11:00 am MWF): ILC 150 Thursday Dec. 14, 11:00 am - 1:00 pm No Exceptions per UA Policy
• The final will consist of 60 multiple choice questions and short answer questions.
• At least 30, but no more than 40 questions, will be taken verbatim from the old quizzes.
Lecture 1-Nats 101 11
Course Grading
•
Course Grading Scale A B C D E 90% or higher 80.0-89.99% 65.0-79.99% 55.0-64.99% < 55.0%
Lecture 1-Nats 101 12
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 Definition • Attend class daily, arrive on time, leave when class is dismissed (courtesy to peer students).
Lecture 1-Nats 101 13
The Golden Rule
Instructor and students all show:
Mutual Respect!
Lecture 1-Nats 101 14
Literacy Requirements
Although the writing requirement for this course is negligible, there is a science literacy requirement. This means that we: • 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 101 15
Announcements
Course Homepage…is functional!
http://www.atmo.arizona.edu/ Click Students and Courses Click Course Links Click NATS101 – Kursinski User Name: nats101 (if established) Password: spring2006 (if established)
Lecture 1-Nats 101 16
Class Format: Lecture Days
• •
2-4 minutes - Interesting weather (if any) 2-3 minutes - Review/Summary/Clean-up From Prior Lecture, Optional
•
60-65 minutes - New Material Lecture, Demos, Discussion
•
2-3 minutes - Wrap-up and Summary
Lecture 1-Nats 101 17
Class Format: Quiz Days
•
10 minutes - Last Minute Questions Passing Out Quiz Materials
•
30 minutes - Quiz
Lecture 1-Nats 101 18
LISTSERV Established
• • • •
Use for any questions, comments, discussions that are general interest to the class.
is reserved for personal requests not of general interest.
To subscribe go to http://listserv.arizona.edu/ and click the link “Subscribe to a list” http://listserv.arizona.edu/Subscribe.html
Follow straightforward instructions!
Lecture 1-Nats 101 19
LISTSERV
If you DID NOT receive an email two days ago, you need to subscribe to the list. You can subscribe by sending an email to [email protected]
with the following as the only line in the body of the message. subscribe xxxxxx Firstname Lastname Substitute the list you want to join for
xxxxxx , i.e. [email protected]
. Substitute your first name for
Firstname
Substitute your last name for
Lastname
Lecture 1-Nats 101 20
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 101 21
Importance of Atmosphere
•
Point 1- Offers Protection Consider surface temperatures
Without atmosphere? 0 o F average, large diurnal swings Similar to the Moon’s Climate With atmosphere… 60 o F average, moderate diurnal swings
Lecture 1-Nats 101 22
Importance of Atmosphere
•
Point 2 - Offers Protection Consider Surface Radiation Shields against harmful UV radiation
Lecture 1-Nats 101 23
Importance of Atmosphere
•
Consider Survival Time Without Food
few weeks Without Water
few days Without Air
few minutes
Lecture 1-Nats 101 24
To Understand the Atmosphere
Sun Atmosphere Examine its interfaces with land/ocean with space Earth 13,000 km Is a very thin skin 99% below 50 km (31 miles) 50% below 5.5 km (3.4 miles) Atmosphere Picture Space
Lecture 1-Nats 101 25
Note “thinness” of atmosphere in light blue 26
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 101 27
Reading Assignment
•
Thomas Friedman NYT Article Homepage Link “Reading Assignments”
•
Ahrens Pages 1-13 Problems 1.2, 1.3, 1.10, 1.14
Lecture 1-Nats 101 28
Atmospheric Composition Permanent Gases
•
N 2 and O 2 are most abundant gases Ahrens, Table 1.1, 3 rd Ed.
•
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
Lecture 1-Nats 101 29
Atmospheric Composition Important Trace Gases
Ahrens, Table 1.1, 3 rd ed.
Lecture 1-Nats 101 30
CO
2
Trend
Keeler Curve from Hawaii Obs Some gases can vary by season and can vary over many years CO 2 increases in spring decreases in fall Ahrens, Fig. 1.3, 3th Ed.
Lecture 1-Nats 101 31
H
2
O Vapor Variability
Precipitable Water (mm)
Some gases can vary spatially and daily
Lecture 1-Nats 101 32
Two Important Concepts Let’s introduce two new concepts...
Density Pressure
Lecture 1-Nats 101 33
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
molecular weight (gm/mole) Avogadro number (6.023x10
23 molecules/mole)
Lecture 1-Nats 101 34
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 101 35
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 29.92 in. Hg
Lecture 1-Nats 101 36
Pressure
Can be thought of as weight of air above you.
(Note that pressure acts in all directions!) So as elevation increases, pressure decreases.
Top Bottom Higher elevation Less air above Lower pressure Lower elevation More air above Higher pressure Lecture 1-Nats 101 37
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 101 38
Why rapid change with height?
Consider a spring with 10 kg bricks on top of it The spring compresses a little more with each addition of a brick. The spring is compressible.
10 kg 10 kg 10 kg 10 kg 10 kg 10 kg Lecture 1-Nats 101 39
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.
Lecture 1-Nats 101
mass
mass
mass
mass
40
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 101 41
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
Lecture 1-Nats 101 42