CIMSS Homepage  GOES Sounder Brightness Temperature
Intercomparisons   HELP   Page

General Information:

This web page is designed to allow users to compare several different types of brightness temperatures related to the processing of CIMSS GOES Sounder single Field-of-View (FOV) physical retrievals (Li et al.(2008)) of temperature and moisture. These retrievals are produced hourly in near-realtime from the Sounder instruments aboard each operational NOAA geostationary satellite: GOES-East (see the region of coverage), and GOES-West (see the region of coverage). As can be seen, the retrieval domain from both satellites combined covers the Continental U.S. (CONUS), plus some adjacent coastal waters. Only data from those retrievals determined as being cloud-free within this domain is included when computing any information presented on this web page.

The web page contains 4 separate regions, or "panels," to use for plotting data. After a given plot has been generated, you can move your mouse along the plot to see specific date/time/data values. If you then try to generate a second plot in the same panel, the default behaviour is to erase the panel prior to generating the second plot. However, if you click on the "Allow overplotting" button, more than one kind of data can be plotted on the same panel. For example, you can plot both the channel 8 and channel 7 observed brightness temperatures on one panel. (In this case, you would probably want to select a different color and(or) symbol to use for the second plot.)

The "... (canned) QuickPlots" menu allows the user to quickly generate plots that may have significant scientific or general interest. For example, GOES-East (13) Sounder channel 15 (4.45µm) has historically been a very noisy channel. The first QuickPlot option allows the user to plot the standard deviation for the last 6 months of observed brightness temperatures for this channel, while the second option will plot the same data, but for GOES-West. It is fairly easy to add other plots to this list. If you wish to add other plots, please contact: E-Mail

To generate a typical plot, 4 basic steps are involved:

  1. Select a range of dates of data to plot. You can either enter the date(s) by hand, or left-click on either text box to bring up a clickable calendar to use. The plot will start at 00UTC on the first date selected, and will extend through 23UTC on the last date selected, unless the last date is the current day, in which case the end of the plot will be the current UTC hour. Once the date bounds have been selected for a given panel, you CANNOT CHANGE the bounds, unless you click on the "Erase the panel" button within the "Plot Options" section.
  2. Select the parameter to plot. Note that you can select from 18 different GOES Sounder bands. Furthermore, you need to select the data to plot, which can be either: 1.) observed or forward-calculated brightness temperatures, or 2.) differences between brightness temperatures. Then for whatever data you decide to plot, you must specify the desired statistic to display. The default statistic to display is average.
  3. Select any plot options. Note that many of the options are determined for the user ahead of time.
  4. After selecting the panel to use for your plot (1 -> 4), click on the "Create Plot" button to generate the plot. Then if you wish to save a PNG file containing your plot, click on the "Save plot as PNG file" button and follow the instructions.
Web page usage hints:
  1. When using the calendar to select either your starting or ending date(s), there are buttons for previous/future months/years to the left/right of the calendar month currently displayed. You should be able to find and use the buttons if you move your mouse within the upper left/right portions of the calendar display.
  2. The earliest allowed starting date for data to plot is: 12Feb2011 (2011043)
  3. The graphing software used in this web page (jqPlot) will automatically determine the Y-axis bounds to use when plotting a graph on a given panel. If you wish to hardwire the Y-axis plotting bounds for a given panel, make sure you set them via the "Minimum value" and "Maximum value" buttons BEFORE creating any plots for that panel!
  4. When plotting widely disparate data on the same panel (e.g., average temperature and standard deviation (SD) of temperature), that can involve a range of several hundred units, it is best to first set the Y-axis bounds to encompass all potential graphs on the panel. In the example, since SD is always >= 0.0, you could first set the Y-axis bounds to something like minimum=0.0, maximum=320.0. If you do not establish the Y-axis bounds being used in these disparate data plotting situations, it is possible one or more of your plots will fail!
  5. If you want to completely reload the web page, clearing all menu selections and panels, simply click on the "Reload/reset entire webpage!" button.
See also:
  1. To see corresponding CIMSS near-realtime GOES Sounder single Field-of-View (FOV) physical retrieval products, please click here.
  2. If you have further questions, please contact: E-Mail
References:

 Li, Z., J. Li, W. P. Menzel, T. J. Schmit, J. P. Nelson III, J. Daniels, and S. A. Ackerman (2008),
    GOES sounding improvement and applications to severe storm nowcasting, Geophys. Res. Lett., 35,
    L03806, doi:10.1029/2007GL032797.


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