isotimic surface

A surface in space on which the value of a given quantity is everywhere equal; isotimic surfaces are the common reference surfaces for synoptic charts, principally constant-pressure surfaces and constant-height surfaces.

Related terms:

• isotimic line
• isotimic
• isobar
• surface weather observation
• isentropic surface
• surface chart
• isohypsic surface
• constant-level surface
• isobaric surface
• baroclinic disturbance