Geography 210H Assignment 4 Due Friday, March 8 The due date for this assignment is extended over a two-week period to allow greater time flexibility for students in their explorations. I am keeping track of the assignments that are completed, whether they reach me on paper or by electronic means. Our subject matter for this assignment encompasses two broad topics: (1) atmospheric pressure, winds, and the general circulation of the atmosphere and oceans; and (2) moisture and precipitation, their global patterns and seasonal variations. I have identified a number of sources for investigation. I will list them here, but the guidelines for this assignment will be in some respects a little less specific than for the previous two assignments. In connection with each site identified below I have framed one or two basic questions that you might investigate, and in some cases I have provided guidelines on a specific option that will allow you to plot spatial and temporal trends that may be of interest. However you don't need to follow these guidelines if you can find something else to do that is both interesting and relevant to the kinds of questions raised here. The minimum assignment is this: pick at least one significant question relevant to each of the two main topics identified above, and investigate available information through the Web in a way that provides some insight into the question that you did not previously have or that augments what you learned from the lecture course. You may choose to formulate your own question after reading the related chapter in the textbook and then go searching the Web for information. You may turn in your assignment on paper, or you may choose to complete the work in the form of messages posted to the newsgroup. I will evaluate your work based not only on whether you perform specific analyses as requested, but also on the degree to which you demonstrate that you are looking at the information accessed and thinking about it. The level of insight and of intellectual curiosity expressed in your comments over the course of the semester will provide the primary basis for evaluating performance. Here is a list of some things worth looking at: 1. http://covis.atmos.uiuc.edu/guide/html/forecast.html Guide to weather maps and images This provides a general introduction to the basics of reading weather maps and satellite images. In particular look at the discussions of surface maps, constant-pressure surfaces, upper-air troughs and ridges, surface contours, iosbars and wind direction, and upper-air contours. 2. Go to the Weather Visualizer: http://covis1.atmos.uiuc.edu/covis/visualizer/ This site offers a menu of options and allows you to generate a current surface wether map of the continent U.S. with pressure readings, isobars, wind barbs, and a variety of other features (my advice is not to clutter it up with too much). Note the relationship between the pressure distribution and the direction and strength of the wind. Can you identify cyclonic or anticyclonic flow? You can also look at multiple slices through the atmospher at different "elevations" (actually different pressure surfaces), such as 850, 500, and 250 mb. Note how the wind patterns change with increasing height. Do you see any visible evidence of jet streams and associated weather patterns? 3. You can also look at the Weatherworld surface maps http://www.atmos.uiuc.edu/wxworld/html/detailed.html which gives you the additional option of animating sequences of surface maps, upper-air maps, or satellite images. 4. The Wxwise Homepage: http://oldthunder.ssec.wisc.edu/wxwise/wxwise.html includes an informative discussion of land and sea breezes and their relevance to larger issues pertaining to winds and circulation patterns. It includes satellite images and an animation. 5. National Science Foundation Weather: http://atm.geo.nsf.gov/cgi-bin/nsfweather provides direct access to data from a station in Arlington, VA. You can look at daily, weekly, or monthly plots. I recommend looking at monthly plots showing both sea-level pressure and wind velocity (display them on separate plots at the same time, not on a single plot). Do you notice any relationship between these two variables? If so, how might you explain it? You can also look at rainfall with the same questions in mind. 7. Weathernet: http://cirrus.sprl.umich.edu/wxnet/maps.html provides access to a very wide range of weather maps. 8. The Purdue weather processor: http://thunder.atms.purdue.edu/surface.shtml provides access to some good surface maps. You can compare sea- level pressure contour maps and surface temperature maps and see whether you can find the location of the subpolar jet stream. 9. NASA Advanced Visualizations: http://globe.gsfc.nasa.gov/globe/sample/advanced.html Includes interesting perspective views of the globe with cloud cover, and also includes an MPEG animation of cloud cover. Looking at this animation, see if you can see any indication of the direction of atmospheric motion. 10. NCDC Climate Visualization: http://www.ncdc.noaa.gov/onlineprod/drought/xmgr.html#gr is a site we visited last time to look at single-station or paired- station temperature patterns. It can access a lot of other variables as well, including pressure, wind speed, and precipitation. Worth exploring. 11. NOAA's Live Access to Climate Data http://ferret.wrc.noaa.gov/fbin/pcgi_bin_v2.0/process_cgi Produces world maps without the continents filled in, but if you can use your imagination over the land areas it has a lot of useful information. You can make maps showing distributions of temperature, pressure, wind speed, and specific humidity (compare January and July) 12. http://www.cdc.noaa.gov/~wkb/research.html#Monthly - rainfall or http://www.cdc.noaa.gov/~jtb/maproom/text/climate_products.shtml contains monthly rainfall images(among other things) that could be quite informative. If you look at several of these you can get an interesting picture of seasonal patterns of rainfall that may or may not conform to the pattern discussed in the textbook. 13. If you didn't read it before, http://www.agu.org/mockler.html provides an interesting introduction to the role of water vapor and clouds inthe climate system. Well worth reading. 14. Also the University of Illinois electronic texbook: http://covis.atmos.uiuc.edu/guide/clouds/html/cloud.home.html has a fair amount of information about cloud types, their formation, etc.