METEOROLOGY 205A
ADVANCED ATMOSPHERIC DYNAMICS
Fall 2007 Prof. Alison Bridger
Mon-Wed 1400-1515 DH 620 ... 924-5206
fax … 924-5191
e-mail: bridger@met.sjsu.edu
web: http://www.met.sjsu.edu/~bridger/m205page.htm
(class stuff will be posted here)
OFFICE HOURS
(tentative)
Mon-Wed
10:45-11:45 & by appointment & by email. Any changes will be announced!
PREREQUISITIES
METR
121A,B (or equivalent), each with grades B or better.
REQUIRED TEXT
J.R. Holton: “An Introduction to Dynamic Meteorology” (4th Ed.). Academic Press (JRH).
BRING TO CLASS – it will be needed for diagrams, equations etc.
ALSO “RECOMMENDED”:
G.J. Haltiner
& R.T. Williams: “Numerical Prediction and
Dynamic Meteorology”. Wiley
(HW).
Was used in the distant past in MET 240 & 205A;
contains some material not covered in Holton, and is a good dynamics reference
(as is the original by Haltiner). Out
of print! Amazon.com shows new/used copies available starting at $90. Look for
a library copy!
C.A. Riegel:
“Fundamentals of Atmospheric Dynamics and Thermodynamics”. World Scientific Publishing Co. (CAR).
MET 121A,B text.
Final
officially
Wednesday December 12, 1215-1430[1] 35%
Assignments weekly 30%
Exams
will be in-class & closed-book.
NOTES
1)
No
class Monday September 3 (Labor Day) or Monday November 12 (Veterans’
Day). Last day of classes is Monday
December 10 = pizza day!!!
2)
I
will probably be at a meeting in the October 8-10 week. We will make
arrangements for missed class time.
3)
The
American Geophysical Union’s annual Fall meeting will be in San Francisco for
the week Dec 10-14. This is a great (and fairly cheap!) opportunity to find out
what is going on in various fields, including dynamics!
TOPICS
(TENTATIVE)
· Review of basics.
A brief review of topics covered in undergraduate
dynamics (e.g., 121A,B) and contained
in Chts. 1-4 of JRH – you should be familiar with
this material.
· Synoptic-scale
motions/Quasi-geostrophic analysis (JRH Cht. 6).
The quasi-geostrophic framework is
used extensively in the study of mid-latitude
synoptic- and large-scale motions and
disturbances. The governing equations
are
systematically simplified to give the
quasi-geostrophic system (as well as other useful
diagnostic tools such as the omega equation).
Within the quasi-geostrophic
framework, we examine the structure of mid-latitude
synoptic-scale disturbances to
answer questions such as: Why do they
have their
observed structure? Must they have this structure? How does the structure relate to the
growth of the disturbances?
· Atmospheric oscillations (JRH Cht. 7)
The atmosphere is full of wave
motions, and with suitable simplifications, the governing
equations can be solved to tell us
about their structure and behavior.
The most significant (synoptically)
are Rossby waves, but we will also look at gravity
and other wave types. We will also
examine Rossby wave propagation in both the vertical and horizontal.
· Atmospheric
Instabilities/Baroclinic and Barotropic Instability (JRH Cht.
8)
Synoptic-scale disturbances are
observed to amplify with characteristic scales in
space and time. This is true in both mid-latitudes and
tropical latitudes, as well as in the
middle atmosphere (10-80 km). We will show that disturbances grow when the
flow is
unstable – either baroclinically, barotropically, or
both.
· Atmospheric Energetics (JRH Cht. 8)
If disturbances grow with time,
where does their energy come from?
Answer = the flow
in which they are embedded. Within the quasi-geostrophic framework, we
will develop
equations that show how energy
quantities (kinetic and potential) vary with time. We
then use these ideas to answer the question of why
observed disturbances have the
structure they do.
· General Circulation (JRH Cht. 10)
What does the time-averaged flow and
structure of the atmosphere look like, and how is
this structure maintained? What role is played by eddies (if any)? What is the Lorenz
energy cycle, and what does it tell
us?
· Final
topic
Depending on available
time, we will look at topics in the Tropical or Middle Atmosphere chapters.
LEARNING
OUTCOMES & THEIR ASSESSMENT
At the conclusion of this course, you should:
·
Be familiar with the full set of the equations of motion (the
primitive equations), the quasi-geostrophic set, and the assumptions that allow
the derivation of the QG system.
·
Understand the benefits of the QG system in terms of being able to
explain the dynamics of mid-latitude cyclonic storms.
·
Understand the technique of linearization, its results and
limitations.
·
Be familiar with a spectrum of wave motions in the atmosphere, and
with wave propagation characteristics.
·
Understand the nature of flow instability, in particular
baroclinic and barotropic instabilities.
·
Understand the energy cycle in the atmosphere, as well as concept
such as Available Potential Energy. Be familiar with the energy cycle
associated with the General Circulation of the troposphere.
·
Understand the differences, theoretically and observationally,
between the Eulerian mean description of the General Circulation, and the
Transformed Eulerian mean description of the General Circulation.
How will these outcomes be assessed?
·
By your performance on assigned work, including assignment
questions and exams.
·
By your participation in the class, which includes full attendance
at classes and exams. This includes participation in class discussions.
·
By your commitment to working on all assigned assignment
questions, initially in group format but ultimately on your own.