wet-bulb depression

[ wet-buhlb di-presh-uhn ]

noun

, Meteorology.

1. the difference between the dry-bulb temperature and the wet-bulb temperature, with a larger depression representing less atmospheric humidity. Compare temperature-humidity index ( def ).

Word History and Origins

Origin of wet-bulb depression¹

First recorded in 1820–30

Example Sentences

One interesting fact to be noticed, after wading through these tables, is this—that, as a general result, the transparency of the air increases about 3·7 times for any increase in dryness from 2° to 8° of wet-bulb depression.

From Project Gutenberg

It was found that the air from the thinly inhabited parts, that is, the north-west quadrant, was nine times clearer than the air from other directions with the same wet-bulb depression, and that the density of the haze was directly proportional to the density of the population of the area from which the wind blew.

From Project Gutenberg

All the observations taken when the wet-bulb depression was between 2� and 4� were put in one table, all those when it was between 4� and 7� in another, and all those when it was over 7� in a third.

From Project Gutenberg

In the tables above referred to along with the number of particles was entered the limit of visibility at the time; when this was done it was at once seen that as the number of particles increased the limit of visibility decreased, as will be seen from the following short table of the Rigi Kulm observations when the wet-bulb depression was between 2� and 4�.

From Project Gutenberg

Aitken for some years made observations on the haze in the air at Falkirk by simply noting the direction of the wind, the wet-bulb depression at the time, and the transparency of the air.

From Project Gutenberg