From: "Dr. Andrew Miller; GEOG" <miller@umbc.edu>

Newsgroups: umbc.course.geog110h

Subject: Next assignment (#4)

Date: Mon, 24 Feb 1997 16:13:21 -0500

Geography 110H

Assignment 4

Due Friday, March 7

Before I say anything else, please note that on Friday, March 7, there will be a special presentation at 1 p.m., probably on the seventh floor of the library, by Tom Horton. Horton is a columnist for the Baltimore Sun and the author of several books about Chesapeake Bay and the environment of this region. You are all invited to attend, and in fact I am willing to consider attendance at the talk as a substitute for the 2 p.m. class. (Of course, how that will affect our ability to sit and talk about the issues raised in this assignment is another matter...)

The due date for this assignment is extended over a two-week period to allow greater time flexibility for students in their explorations. However you may want to visit some of these sites before studying for your exam next week.

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: for each of the two main topics identified above, pick at least one significant question.

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 in class. You may choose to formulate your own question after

reading the related chapter in the textbook and then go searching the Web for information.

Here is a list of some things worth looking at:

1. http://covis.atmos.uiuc.edu/guide/guide.html

The University of Illinois Onlide Guide to Meteorology has a number of different modules on topics related to atmospheric pressure, pressure gradient force and the Coriolis effect, winds, fronts, land and sea breezes, clouds, El Nino, weather maps, hurricanes, etc. A good site for some review before (and after) an exam. In fact, you can use this site as a supplementary text for the next three chapters of the book.

One of the options at this site is:

http://covis.atmos.uiuc.edu/guide/wmaps/html/weather.home.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 weather map of the continental 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 atmosphere 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. 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.

4. NSF weather at Arlington, Virginia

http://atm.geo.nsf.gov/cgi-bin/nsfweather

and

NSF weather at National Center for Atmospheric Research http://www.atd.ucar.edu/cgi-bin/mlabweather

provide direct access to data from local weather stations at those two locations. You can look at daily, weekly, or monthly plots. I recommend looking at monthly plots showing both

sea-level pressure and wind velocity. Look at weekly plots if you need a more detailed view with better resolution. 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.

5. Weathernet:

http://cirrus.sprl.umich.edu/wxnet/maps.html

provides access to a very wide range of weather maps. You can find some really unusual things here, like a map of lightning strikes, a snow-cover map, a jet-stream analysis, an image showing distribution of precipitable water in the atmosphere, and others. (Of course, some of these maps actually come from other locations.)

6. The Purdue weather processor:

http://wxp.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. Note that this site can be quite slow - if it's not responding, go somewhere else.

7. NASA Advanced Visualizations:

http://globe3.gsfc.nasa.gov/cgi-bin/show.cgi/page=gallery-advanced.ht

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.

8. 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.

9. 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)

10. 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. (Recommended!)

11. 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.

12. The University of Illinois atmospheric sciences home page also has a separate list of pages devoted to ocean-atmosphere interaction, including El Nino:

http://covis.atmos.uiuc.edu/geosciences/instructional/atmossci/ocean.html