isentropic thickness chart

A thickness chart of an atmospheric layer bounded by two selected isentropic surfaces (surfaces of constant potential temperature); the thickness of such a layer is directly proportional to the static instability of that layer; hence, these charts have been called instability charts. Also known as thick-thin chart.

Related terms:

• isentropic weight chart
• thickness chart
• isentropic chart
• thickness
• geopotential thickness
• thickness line
• isentropic mixing
• thick-thin chart
• constant-height chart
• thickness pattern