5. Glossary


A sequence of two (pressure, temperature) pairs that specify the bottom left-hand corner and the top right-hand corner of the plot. The pressure data points must be in units of mb or hPa, and the temperature data points must be in units of oC.

dry adiabat

A line of constant potential temperature, measured in units of oC. The zeroth dry adiabat line is an axis of the tephigram, see Dry adiabats.

humidity mixing ratio

A line of constant saturation mixing ratio with respect to a plane water surface, measured in g kg-1, see Humidity mixing ratio.


A line of constant pressure, measured in millibars or hectopascals, see Isobars.


A line of constant temperature, measured in oC. The zeroth isotherm line is an axis of the tephigram, see Isotherms.

line specification

A sequence of one or more tuple pairs containing a line step value and a zoom level value. Used to control the frequency at which the tephigram plots isobar lines, humidity mixing ratio lines, and saturated adiabat lines. Note that, specifying a zoom level of None forces the associated lines always to be visible.

line step

The first value in the tuple pair of a line specification. An integer that denotes Nth step multiples. i.e. a line step of 25 denotes all lines that are a multiple of 25, or every 25th item from an enumerated list of values.

pseudo saturated wet adiabat

A line of constant equivalent potential temperature for saturated air parcels, measured in units of oC, see Pseudo saturated wet adiabats.

saturated adiabat

See pseudo saturated wet adiabat.

zoom level

An inverted zoom level fraction that is a ratio of current tephigram plot display width over the original plot display width.