ATSC5160      Midterm 2002            due Monday 25 March 5 pm firm (22%)

 

Some questions are from the set of problems at the end of Parts I and II in Bluestein (1993). Others are original. This is an individual effort, with unrestricted resources. Answer 6 questions in total, from a total of 8 questions listed (you have to do 1 and 2). Good luck ! The midterm should be graded by the end of next week.

 

 

1. (a) Use IPV thinking to demonstrate that an upper-level positive PV anomaly, located a quarter wavelength to the east of a low-level positive PV anomaly in an environment where dU/dz ~ -dT/dy >0, is cyclolytic, ie both the UL and the LL PV anomalies will weaken.

1. (b) Demonstrate that this statement (a) is independent of hemisphere.

 

2. Coastally-trapped wind reversals (CTWRs) frequently occur along the US west coast in summer. They are accompanied by a northward surge of stratus or fog, and a wind reversal. Discuss the large-scale and mesoscale dynamics of these CTWRs. Your discussion should be original, and should make reference to the literature as in any paper. For your reference list, use the AMS journal standard. Conciseness is encouraged, with a maximum length for this discussion of 3 pages (1.5-spaced, font 12). Your discussion should cover the following (not necessarily in this order):

  • the seasonal variation of CTWR events
  • the prevailing wind and pressure pattern along the west coast in the relevant season
  • a description of the evolution of a CTWR, including
    • the variation of the CTWR strength normal to the coast line
    • the variation of the depth of the marine boundary layer (BL), both along and across the coastline
    • the variation of wind direction before and after the passage of a CTWR
  • the trigger for a CTWR onset
  • the significance of upper-level ridging and/or a frontal wave disturbance
  • the reason for the coastal trapping
  • the occurrence of stratus, and its feedback on the evolution of a CTWR

 

choose 4 of the following 6 questions

  1. Question 2.44 in Bluestein: additional assumption: the horizontal wind field shown in the figure applies to the locations of the southeastern (-15) and northwestern (-25) isotherms (and vertical motion contours), and this wind field varies linearly in between.

 

  1. Question 2.38 in Bluestein
  2. Question 2.14 in Bluestein
  3. Question 2.9 in Bluestein
  4. Question 1.47 in Bluestein
  5. Question 1.29 in Bluestein