OBSOLETE - Ferret V5 no longer exists.
Using Ferret "Live Access Server" data
A rich source of data is the NOAA live access server. Here you can get data that is not available on the WorldWatcher CD and that is very useful in exploring ocean structure, as well as accessing data that is more recent than that from WorldWatcher.
Note: There are various versions of the Live Access Server, and it works with different browsers on different computers. On Macintosh, it will work best on version 4.7x of Netscape. You can find old versions for download at: http://wp.netscape.com/download/archive/client_archive47x.html. PC users have a better situation. It should work with most versions of Explorer.
Definitions you will need:
Climatology: concerns averages of data. For example, the SST (sea surface temperature) for month of January would consist of an average of sst data for January for many years.
Meridional: North-South component. For example, a positive value of the meridional winds would be the component of wind flow in the South to North direction.
Zonal: A positive zonal wind would be the component of wind flowing from East to West. If the zonal and meridional components of the wind were equal and positive, wind would be flowing from SoutheEast to NorthWest.
Tutorial for Version 5 of the Live Access Server
Tutorial for Version 6 of the Live Access Server
The figure below shows what you see when you access this site. It is targeted for researchers, but is also easy to use for students.
:
Follow this short tutorial to get started:
1. Open your browser and go to http://ferret.wrc.noaa.gov/las/. If the page does not look like that above, access the "idiosyncrasies" link to figure out what's wrong. Or, better yet, try the version 6.0 Live Access Server link above. This site does not work with Internet Explorer, but it is very valuable and it is worth your while to download Netscape to view it.
2. Wait. It takes awhile for all of the java code to load.
3. In the left hand panel, find “Levitus (1982) global seasonal climatology."
4. Click on the (+) sign at the left of the entry.
5. After the panel updates, you should see a listing like the one shown to
the left. Click on “Salinity.” The text will turn red.
6. Now click on “Get Data.” In a few seconds, a window that is a plot of the global salinity averaged over many years, for March. If you want to save this save it to your disc drive, as explained in lab 1.
Now, let’s get a salinity cross section of the Atlantic Ocean.
7. Click on the close box at the upper right hand corner of the window containing the salinity plot.
8,. From the “Select View” popup menu, select “xz lat/depth slice.” You will see a vertical line on the selector map. Move the vertical line so it bisects the Atlantic Ocean.
9. Click “Get Data,” and you will get a plot that is similar to the one shown in Figure 9.
You will find the datasets that can be displayed to be very pertinent to your investigations. Ignore and datasets that you can’t understand. Use the information icon at the left of the dataset selection line to get a bit more, sometimes rather cryptic, information about the data.
Examples:
Salinity plot from NOAA “Live Access Server.” Notice that the salinity is highest at mid-latitudes.
Cross section of salinity, in a North-South direction through the Atlantic Ocean. Notice that the salinity decreases with depth and is highest, and high salinities extend deepest, in mid-latitudes. Can you spot where high salinity water flows out of the Mediterranean Sea?
Newer versions of the Live Access Server (version 6.0): Here is a link to version 6. It works a bit better on Macintosh computers. It's user interface is a bit simpler, but also more cumbersome. The basic idea is similar to the tutorial above. Choose the "select dataset" link from the first page that is displayed after you click the link below.