SAN FRANCISCO STATE UNIVERSITY Meteorology 430 DEPARTMENT OF GEOSCIENCES Fall 2010
1. For questions involving use of equations or calculations, lay out all equations carefully, show all units, show all steps, number equations sequentially.
2. For questions involving analysis or mapping techniques, use proper color conventions, use proper mapping techniques (NO grease pencil on final copies).
3. This examination is open book, open notes.
4. Answer on separate sheets or on back of exam.
Part A. Surface Charts (100 points)
1. The first chart included in the group of charts labeled “Part A Charts” is a print of sfcwxall showing
surface observations in the eastern Pacific, and nam_maps nam_thick for 12 UTC 12/11/06. First, draw advection arrows and do a frontal analysis on nam_thick. (30 points)
2. Using your results in 1 above (the last question above) do a surface synoptic analysis on the unanalyzed chart IN THE DASHED BOX. The analysis will be graded for meteorological accuracy, proper color and analysis conventions AND neatness. Use the other charts provided (and any other map or chart included in this exam) for insight. Also, although you will not be contouring outside the dashed box, you should use the observations (that are readable) outside the box to help you (70 points)
Part B. Relation of Upper Air to Surface Patterns (150 points)
1. The simplified vorticity equation in natural coordinates is
a. Name and describe each term in equation (1). Then identify the term that can be dropped from equation (1) when applying it to the synoptic scale vorticity and divergence fields in the upper troposphere? (Don't explain WHY the simplification is made. Just state what it is and what the resulting equation looks like). (50 points)
b. In the group of charts labeled “Part B Charts,” you will find the 300 mb absolute vorticity advection contour plot and the contour plot of the 300 mb absolute vorticity field for 1200 UTC 12/11/06. Using the equation you simplified in the previous questions, provide an estimate of the 300 mb horizontal divergence at location A. (Show all steps!) (40 points)
c. Compare/contrast the divergence you computed to that actually observed, as depicted on the contour plot of the actual 300 mb divergence field provided in Part B Charts. (20 points)
d. One of the charts included in Part B Charts shows the surface pressure tendency for the 3 hours ending. Does the pattern at A correspond to what you would expect from the pressure tendency equation , assuming that the sign of 300 mb divergence field is an estimate of the net divergence over the region? Explain. (20 points)
e. Compare the 500 mb vertical velocity field (given in Part B Charts) for 1200 UTC 12/11/06 with your results in (b) and (c). Do the vertical velocity values at A qualitatively correspond to what you would expect from Dine’s Compensation, assuming that the sign of 300 mb divergence field is an estimate of the net divergence over the region? Explain. (20 points)
1200 UTC December 11, 2006
Part A Charts
Part B Charts