Geography 110H
First Assignment for Fall 2000
Due Sept. 7, 2000
This assignment consists of three parts. The first is more conceptual and asks you to apply some of the concepts in chapter 1 of the textbook to one of two questions. The second asks you to do a little research to come up with a definition pertaining to the technology and software used in modern physical geography and environmental science. The third asks you to look at some aspects of earth-sun relations and their implications, which may include graphical analysis of trends in quantitative data.
In order to complete this assignment, you should log into the course website, click on "Communications" and go to the discussion board in order to post your answer to questions 1 and 2. Your answer to question 3 can also be posted to the discussion board. The answer to question 4, if done in digital form, can be turned in by going to "Student tools" and then clicking on "Student dropbox" in order to upload the file. We will talk in class about how to do this.
1. Apply the systems concept as described in the book to one of the following two scenarios.
a. Recent wildfires across much of the western U.S. can be looked in terms of causes and impacts. Describe what may happen in the aftermath of these fires in terms of the systems concept as described on pages 7 to 12 in Christopherson. In other words, define your system (e.g. the entire western U.S., the forest ecosystem within a burned area, the soil subsystem, the forest and the overlying atmosphere, or what have you) and discuss how the fires affect both processes internal to the system and processes that connect the system with its external environment. For class discussion try to draw at least one chart illustrating these relationships.b. Recent observations suggest dramatic warming in the Arctic near the North Pole, such that there are areas clear of sea ice that appear to be much larger and longer-lasting than at any time in recent memory. Describe these changes in terms of the systems concept as described on pages 7 to 12 in Christopherson; the system you choose can be either global or local in scale, but you should try to illustrate with a chart at least one set of relationships that either have a role in causing the recent trend or that may lead to further consequences of that trend.
For either one of these topics, it would make sense to draw on additional sources of information that explain what is going on and what may be causing it. Once you have some information to go on you can try to analyze it in terms of the systems concept. Be prepared to discuss your answer in class.
2. Come up with a definition of either GPS or GIS and explain how it
(whichever one you choose) is applied to a real problem or question in
physical geography; find a real example to illustrate what you mean.
3. Earth-sun relations that govern the duration of daylight and the location of the circle of illumination can be illustrated using the Earth Viewer at the following location:
http://www.fourmilab.ch/earthview/expert.html
You can see the areas in sunlight and darkeness for the particular moment at which you are visiting the site, and you can choose to look at a flat map or a global view centered over any location of your choosing. (The images load slowly, so you may not want to do this at prime time.) If you look at a flat topographic map, note the shape of the line dividing day from night. Now look at it on a global view (click on "above location" and select a latitude, longitude, and altitude above earth's surface before clicking on "View Earth"). What does this say to you about the information provided on maps and the interpretation of coordinate systems?
Try several different views from different latitudes (including polar and equatorial views) and compare what you see with the discussion in the textbook of earth-sun relations for different seasons.
4. The U.S. Naval Observatory maintains a web site called the Directorate of Time. Here is its address:
http://tycho.usno.navy.mil/srss.html
A subset of this web site will allow you to calculate times of sunrise and sunset for one day any location expressed in geographic coordinates:
http://aa.usno.navy.mil/AA/data/docs/RS_OneDay.html
or, alternatively, at the following site, if you type in the name of a U.S. town or city, you can get a whole year's worth of sunrise and sunset times:
http://aa.usno.navy.mil/AA/data/docs/RS_OneYear.html
Visit one of these sites and find times of sunrise and sunset as well as length of daylight for the 22nd day of each month through the year, for each of several latitudes. Tabulate this information and make a plot showing how either time of sunrise and sunset or duration of daylight varies by month; superimpose plots for several different latitudes on the same page. You can also pick a single date and plot how duration of daylight varies with latitude. I will accept any combination of graphs that shows you have explored the range of variation by date and location; provide a brief discussion that relates your observations to the discussion of earth-sun relations in the textbook.
Here's another page with information about the time of "apparent" sunrise and sunset and why it differs from the time of "real" sunrise and sunset: