NATS 101, Sections 31 and 32

Homework #6 – Seasonal Changes around the Globe

Due in class on Monday, April 28, 2008

 

April 23.  I have placed additional suggestions / information within this assignment.  These are shown in red below.

 

Your assignment is to choose three cities located at vastly different latitudes, gather some astronomical and climatic information about each of them, place this information in a table, and write a paragraph summarizing the differences between them.

 

Selection of cities.  The first city must be located well within the tropics, latitude must be less than 15°; the second city must be located in the lower middle latitudes, latitude must be in range from 30° to 45° (includes most of the continental United States); and the third city must be a high latitude location, latitude must be higher than 60°.  You are free to choose any cities in the world as long as one is located within each of the three latitude zones specified above and you can dig up the required information.  Please select your own cities.  If multiple students select the same three cities, those students will not be given credit for this assignment!

 

Information to collect.  The data you gather should be placed into a table.  The table will be composed of 15 columns of data.  Here is a list of the required columns:

  1. Name of city
  2. Country that the city is located in
  3. Latitude of the city.  Be sure to indicate either north or south latitude.
  4. Local time of sunrise on the 2008 summer solstice (June 20, 2008).  If your city has 24 hours of sunlight or darkness, enter N/A in the corresponding column.
  5. Local time of sunset on the 2008 summer solstice (June 20, 2008).  If your city has 24 hours of sunlight or darkness, enter N/A in the corresponding column.
  6. Length of day (sunlit hours) on 2008 summer solstice.  You can figure this using the information that you entered in columns 4 and 5.
  7. Solar angle at noon on the summer solstice.  Calculate this value based on the latitude of your city and using a solar declination of 23.5° North latitude.  Be careful to define the solar angle the same way that we have done in class.  We defined it as the angle between the sun and straight up.  So when the Sun is directly overhead (straight up) at noon, the solar angle is 0°.  Some websites include a value for solar angle at noon.  Make sure they define the angle the same way that we do in class.  Just to be sure and to practice for the quiz, I suggest that you compute the solar angle yourself instead of copying it from a web page.  The difference is that some sources of information measure the sun angle from the horizon instead of straight up.  Under that system, when the Sun is directly overhead (straight up) at noon, the solar angle is 90°.  YOU NEED TO USE OUR DEFINITION OF SOLAR ANGLE ON YOUR HOMEWORK. 
  8. Local time of sunrise on the 2008 winter solstice (December 21, 2008).  If your city has 24 hours of sunlight or darkness, enter N/A in the corresponding column.
  9. Local time of sunset on the 2008 winter solstice (December 21, 2008).  If your city has 24 hours of sunlight or darkness, enter N/A in the corresponding column.
  10. Length of day (sunlit hours) on 2008 winter solstice.  You can figure this using the information that you entered in columns 8 and 9.
  11. Solar angle at noon on the winter solstice.  Calculate this value based on the latitude of your city and using a solar declination of 23.5° South latitude.  See Comment in red above under point #7.
  12. Warmest month of year, based on monthly average high temperature.
  13. Monthly average high temperature for this month.  All values in this column should be in the same units (either Fahrenheit or Celsius).
  14. Coldest month of year, based on monthly average high temperature.
  15. Monthly average high temperature for this month.  All values in this column should be in the same units (either Fahrenheit or Celsius).

 

Presentation of results.  All of the information above must be presented in a table.  Therefore, you will need a table with 4 rows (one heading row to label the columns, and one row for each of the three cities), and the 15 columns specified above.  If using WORD, your table will have to be 15 by 4.  You are free to lay out your table with 4 columns (one heading column to label rows, and one for each city) and 15 rows (one for each of the 15 items specified above.  You will have to decide how to lay out this information on a page to make a nice, easy-to-read presentation.  One possibility is to try to lay out your results in a landscape orientation rather than a portrait orientation.  If you are unable to fit your entire table neatly across the page, you may decide to somehow split up groups of columns (or rows) on multiple lines, but the rows (or columns that you use for the cities) should not be split up, so that a reader can easily compare the three different cities.  If you decide to do this, you should re-label the city name in the far right column (or top row), so that a reader can easily match the correct information with the correct city.  The reader must also be clear about what information is contained in each column (or row).  For column (or row) headings, you can label them fully within the table or use footnotes.  An example of how to use a footnote would be to label a column (or row) using a number in parentheses {for example, (7)}, then below the table explain each footnote, for example

            (7) Solar angle at noon on the summer solstice in degrees.

 

Summary paragraph.  After presenting your table, you need to write a summary paragraph that compares the seasonal changes (yearly ranges) in length of day, solar angle at noon, and monthly average high temperature among the three cities you selected.  You should also work in some kind of general statement about how the severity of seasonal changes is related to latitude (location on Earth).

 

Grading.  50% of the grade will be based on the correctness of your data and calculations; 30% will be based on neatness and presentation of the results; and 20% will be based on what is contained in the summary paragraph (both content and grammar). 

 

Where to find information / preciseness of information.  I will leave where to find information to you.  It should not be difficult.  Much is available on line (use search engines).  Try not to become fixated with a particular city.  If it is difficult to find information for a city, try another one.  Local times and length of day numbers should be within the nearest minute, i.e., you do not have to include seconds in your results (unless you want to).  The latitude for each city can be rounded to the nearest integer number in degrees, i.e., you do not have to include minutes and seconds of latitude in your results (unless you want to).  You may not be able to find both the sunrise/sunset times and the average temperature information for each city using a single web site, i.e., you may have to find information using more than one web site.