SNMAP plots any parameters which can be derived from the data in a GEMPAK sounding data file for specified levels and vertical coordinate.
SNMAP runs similarly to SFMAP. The only fundamental difference is that SNMAP will map sounding (upper air) data instead of surface data. As a result, you must define the level GLEVEL and vertical coordinate GVCORD on which to map the data.
GDMAP is very similar to SFMAP and
SNMAP. The only fundamental difference is that GDMAP will plot gridded data
points on a map. Usually, however, we use contours, streamlines, or vectors
to view gridded data, so this program is of limited use.
We'll discuss the new variables unique to grid programs in the
Grid Programs section. Consult the on-line
help file, or the User's Manual for information on how to use this program.
In this chapter, we have learned how to plot data on maps. In general, these programs are more heavily used than listing programs, which we will cover in the next chapter. Listing programs provide textual representation of the data; mapping programs
provide a mapped representation. The next chapter will provide a third
representation of data--graphs. After working through this chapter, you should now be familiar with:
Before moving on to the next chapter, test your GEMPAK skill by working
through the Mapping Program Exercises.
After each question, there will be a answer window
The next chapter discusses graphing programs. These programs are used
to represent data without the geo-referencing. Examples include meteograms
and Skew T-Log P plots. Cross section programs are also included in this
category.
3.1.3| GDMAP
3.1.4| Mapping Exercises
Both the maping and listing programs run in the same general way. The variables are the same or are analogous, and both can represent the three types of data.
.
Work through the exercise, and then check your results against the answers.