tephigram

tephigram

[′tef·ə‚gram]

(meteorology)

A thermodynamic diagram designed by Napier Shaw with temperature and logarithm of potential temperature as coordinates; isobars are gently curved lines and the chart is rotated so that pressure increases downward; vapor lines and saturation adiabats are curved; on this chart, energy is proportional to the area enclosed by the curve representing the process.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

tephigram

An aerological map on which temperatures and potential temperatures (pot temp) are marked along the X- and Y-axes, respectively. Tephigrams are used to ascertain the stability of the atmosphere. Information about the MINTRA level i.e., the minimum flight level above which contrails will form) and the DRYTRA level (i.e., the maximum flight level above which condensation trails will not form) are also obtained from the tephigram.

An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved