GE 172                                                                                                            Prof. John E. Ebel

Weather, Climate and the Environment                                                           November, 2009


Second Midterm Exam


This exam is an in-class, closed book exam covering primarily chapters 6-10 of the textbook.  Some prior material may be useful in answering some of the questions.  Please write all your answers in the blue books that are provided.  There are a total of 100 points possible on this exam.  Please keep in mind the university rules concerning academic integrity.  Good Luck!


Part I.  Definitions (4 points each)


    Please give a concise definition for each term listed below in your blue book.


1. Cyclogensis

2. Conditionally unstable air

3. Cold front

4. Collector raindrop

5. Arctic airmass


Part II.  Multiple Choice (4 points each)


     Please write the most correct answer for each question in your blue book.


6.  As a chinook wind is drawn down the leeward slopes of a mountain range

                   a.  the air temperature rises.

                   b.  the saturation vapor pressure increases.

                   c.  the relative humidity decreases.

                   d.  All of the above are correct.

                   e.  None of the above is correct.


7.  A cloud that completely covers the sky and is made up entirely of ice crystals is

                   a.  a cumulus cloud.

                   b.  an altostratus cloud.

                   c.  a lenticular cloud.

                   d.  a cirrostratus cloud.

                   e.  None of the above is correct.


8.  At the center of a polar high, the horizontal pressure gradient is weak and winds are

                   a.  strong.

                   b.  moderate.

                   c.  light or calm.


9.  The northeast trade winds

                   a.  are the product of a strong Coriolis force.

                   b.  span the horse latitudes.

                   c.  are the result of air flowing from the subtropical high to the ITCZ.

                   d.  have been the dread of sailors for centuries.


10.  As a warm type occluded passes

                   a.  the air temperature goes from cool to cold.

                   b.  the air temperature goes from cool to hot.

                   c.  the air temperature goes from cold to cool.

                   d.  the air temperature goes from cold to hot.

                   e.  None of the above is correct.


Part III.  Fill in the blanks (4 points each).


     Please write the most correct answer for each question in your blue book.


11.  In an inversion layer, the air temperature  _____________________ as one goes up in elevation.


12.  Strong north-south flow in the mid-latitude westerlies is called  __________ flow.


13.  The process by which snowflakes grow is called the ____________________ process.


14. ___________________ air masses are warm, moist air masses.


15. Deserts like the Sahara in Africa form under semi-permanent systems that have  _______________ air pressure.


Part IV.  Diagrams (8 points each).


     Please draw and clearly label each of the following sketches in your blue book.


16.  Make one or more sketches to illustrate how raindrops form.  As part of your answer, be sure to indicate why all cloud droplets do not turn into raindrops.


17.  Please make one or more sketches to illustrate how the geostrophic wind forms.  Be sure to label the important forces that act on the air to drive that wind.



Part V.  Essays (8 points each).


     Please answer concisely each of the following questions in your blue book.  An answer of no more than 5-6 sentences should be sufficient for each question.


18.  Please briefly explain why upwelling of cool water occurs along the west coast of South America.  What happens to this upwelling during an El Nino episode?


19.  Please briefly describe the different air masses that typically affect Boston area weather in the wintertime.  From what areas do each of these air masses originate?


20.  What is vorticity, and how does it affect the formation of mid-latitude cyclones?