millibar Meteorol.
(ˈmɪlɪbɑː(r))
[f. milli- + bar n.6]
The usual unit of barometric pressure, equal to one thousandth of a bar (bar n.6 2), i.e. 1000 dynes per sq. cm.
| 1910, etc. [see bar n.6 2]. 1914 Q. Jrnl. R. Meteorol. Soc. XL. 187 The megadyne per square centimetre has been adopted and called the ‘bar’... The bar is less convenient for printing and conversation than the millibar, its 1/1000th part, and the latter has therefore been generally adopted; it is equivalent to the pressure produced by about three-hundredths of an inch of mercury or by three-quarters of a millimetre. 1924 Glasgow Herald 23 Dec. 5 So far as I can judge from the synoptic chart for December 9, 7 a.m.,..the pressure at New Pitsligo at 7 a.m. seems to have been 1016 millibars, and by noon to have risen to about 1012 millibars, equivalent to 30·12 inches. 1942 V. C. Finch et al. Elem. Meteorol. v. 104, 1/10 inch on a barometer or barograph is equivalent to about 3 millibars. Either inches or millibars may be used in numbering the isobars on a weather map. 1963 G. M. B. Dobson Exploring Atmosphere i. 3 A scale at the side of the frontispiece gives the average pressure at different heights in millibars (mb), where 1000 mb is approximately the average pressure at sea level. |