Geography Reference
In-Depth Information
that indicates relationships between fronts, jet-stream, and so on. By consid-
ering temperature measures made at other points in time in the area, the
comparison of different temperature measures leads to some understanding
of the underlying processes.
These comparisons can be made visually, but are then plagued by uncer-
tainty. Scale is an important factor: if we consider temperature differences in
the entire United States, then it will be very difficult to tell clearly what the
differences in temperatures are between Philadelphia and Baltimore. Visual
symbols, especially color, may be easily misinterpreted. The comparisons will
also run into difficulties when a person tries to compare temperature
changes over a year, or even over a season, if the detail is significant, because
of the large number of temperature maps. A person might be able to inter-
pret differences between five maps of the United States, but comparing 500
temperature maps would be impossible for almost anybody.
Geostatistics takes a mathematical approach and works directly with the
underlying measurements. By working directly with the measurements, one
can examine the relationships between places and the processes in more
detail regardless of scale, regardless of different visual interpretations of
color, and regardless of the number of maps. In other words, even if the sta-
tistical operations are simple comparisons, mathematics helps one to get a
grasp on the complexity of mapping far more readily than visual techniques.
Additionally, because the measurements are being used directly, they can be
used for other analysis operations that can aid one in understanding the
accuracy and validity of the measurements and provide insights into climatic
processes both at the places where the measurements are made and the
places in between.
Patterns indicate characteristics or phases of processes, but all relation-
ships between patterns and processes are very complex. Other factors may
need to be considered for more accurate insights into weather processes.
While temperature is important, it is only one indicator of weather. It also
varies considerably during the day, based on exposure to winds and the sun,
according to locations, and so on. Measurements of these aspects should be
considered with temperature to gain a better understanding of the pro-
cesses.
You also need to be aware of the complexity of establishing, creating,
and validating measurements. When measurements are collected on the
environmental characteristics of things and events, they are usually collected
at distinct places. How these places are determined is a crucial question for
assessing the reliability and validity of the measures. The sampling distribu-
tion must be carefully decided on based on an analysis of known properties
and processes, or through a simulation of the patterns and process to be
studied. The types of instruments and the types of measurements are
another important point to consider. If different instruments are used in dif-
ferent places, the measurements may be significantly different. If the exact
differences can be ascertained, it may be possible to transform the measure-
ments to a common reference system. For example, measurements of tem-
perature in Fahrenheit and Celsius need to be converted to one system
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