Isolines are lines where the value of a
variable stays constant. In
meteorology, there are many different types of isolines. These isolines are used to analyze
weather maps and to make future
forecasts. Here are some of the many types:
- Isobar
a line of constant pressure
- Isotherm
a line of constant temperature
- Isodrosotherm
a line of constant dew point temperature
- Isohypse
a line of constant height above sea level
When drawing isolines on a map, different colors are used to represent different types. Isobars and Isohypses are black. Isotherms are red, and isodrosotherms are green.
Also there are guidelines to follow when analyzing a map with isolines. They are as follows:
- All data points along an isoline have the same value
- The interval between isolines is a constant value on any one map
- Lower values are always on one side of an isoline while higher values are on the other side.
- Isolines cannot cross or touch.
- Isolines never split.
- Isolines will generally tend to be smooth and parallel.
- Interpolation between points should be as exact as possible
- Do not draw lines where there are no data points.
- If possible, connect isolines of the same value
- Label each open isoline on its ends and each closed isoline in the center.
- Isolines must be drawn so as to separate or include all data points.