SAN FRANCISCO STATE UNIVERSITY
Name ___________________________________
DEPARTMENT OF EARTH & CLIMATE SCIENCES
Fall 2013
TEST 1 (200 points)
Part I. Quasigeostrophic Omega Equation (75 points)
The quasigeostrophic omega equation is
æ 2 fo2 ¶ 2 ö
fo ¶ é
2
ù- R
w
=
-V
·
Ñ
z
+
f
Ñ
-Vg · Ñ pT )
çÑ p +
÷
(
)
(
g
p
g
ë
û
2
¶
p
s
p
s ¶p ø
s
è
Term A
Term B
æ
ö f
-R
Ñ 2 ç 1 dQ ÷ - o ¶ (-K f z g )
s p è Cp
dt ø s ¶ p
Term C
Term D
where forcing terms for diabatic heating (Term C) (where Q is sensible heating) and
friction (Term D) are also included. For the following question you can assume that
ONLY Term D (differential effects of friction) is small and can be neglected.
a Discuss why in discussing the forcing for upwards omega the terms A and B can
be neglected during the summer in the middle and upper troposphere over the
United States; (40 points)
(b) Examine the potential temperature pattern (next page). Assume that the pattern
represents the average daily DIURNAL HEATING (in other words, assume that
the chart shows the heating that produces a change in potential temperature from
morning to afternoon). This effect is maximum at the ground and decreases with
height, but is still present, at 700 mb and abovec. Given your answer in (a)
discuss the average daily nature of the forcing for 700 mb qg omega over the
western United States (35 points)
Part II. Gigantic, Stupendous Case Study (125 points)
For Part A. Attached at rear of exam find the following charts for 12 UTC 3/1/07:
(a) 500 mb heights/Absolute Vorticity—nam_vort
(b) Sealevel Pressure/1000-500 mb Thickness—nam_thick
(c) Unanalyzed Surface Plot
(d) 850 mb Heights and Isotherms
(e) 500 mb Heights and Isotherms
(f) 300 mb Heights, Isotachs and Isotherms
(g) Radar Composite
(h) Enhanced Infrared Sat Image
(i) Soundings for Oklahoma City and Birmingham
For Part B. Attached at rear of exam find the following charts for 00 UTC 3/2/07:
2
(j) 500 mb heights/Absolute Vorticity—nam_vort
(k) Sealevel Pressure/1000-500 mb Thickness—nam_thick
(l) isothva
(m) 700 mb Q-vector Convergence
Part A. Analysis (Done in Lab on Monday 7 October; Please Turn In Before Test on
Wednesday 9 October)
Part B. Forecast for QG-Forced Omega over northwest Mississippi at 0000 UTC 3/2/07
1. Using (j) and (k), characterize the QG-forced omega at 700 mb forecast to occur over
extreme northwest Mississippi at 00 UTC. Please be careful to list the assumptions you
made in using these charts to estimate the nature of the 700 mb QG-forced
omegapts)
2. Using (l) and (m), characterize the QG-forced omega at 700 mb forecast to occur over
extreme northwest Mississippi at 00 UTC. (20 points)
3. Discuss the extent to which your results in (1) just above are consistent or
inconsistent with your results in (2). (20 points)
3