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Standard Atmosphere

The standard atmosphere is "a hypothetical vertical distribution of temperature, pressure, and density that, by international agreement, is taken to be representative of the atmosphere for the purposes of pressure altitude calibrations, aircraft performance calculations, aircraft and missile design, ballistic tables, etc." (Glosssary of Meteorology, 2000). Essentially, the standard atmosphere represents an average vertical profile of temperature, pressure and density.

Shown below are the height of standard pressure surfaces from 850 mb to 50 mb based on latitudinal variations of standard atmosphere values. Two tables are given, one for the Northern Hemisphere Winter and one for the Northern Hemisphere Summer. The same pressure altitude values and 15N annual values are presented in each table.

Northern Hemisphere Winter (January)

All values are in feet unless otherwise specified.

Pressure Pressure
Altitude		 75 N lat 60 N lat 45 N lat 30 N lat 15 N
Annual
50 mb 67,507 64,101 65,551 66,873 67,224 67,694
100 mb 53,084 50,194 51,204 52,513 53,570 54,281
150 mb 44,646 41,959 42,762 44,052 45,466 46,467
200 mb 38,661 36,060 36,759 38,022 39,567 40,528
250 mb 33,999 31,470 32,103 33,323 34,843 35,692
300 mb 30,066 27,707 28,301 29,432 30,833 31,578
400 mb 23,573 21,611 22,152 23,035 24,213 24,777
500 mb 18,287 16,686 17,133 17,838 18,819 19,229
700 mb 9,882 8,921 9,137 9,613 10,243 10,384
850 mb 4,780 4,245 4,367 4,678 5,033 5,016

Northern Hemisphere Summer (July)

All values are in feet unless otherwise specified.

Pressure Pressure
Altitude		 75 N lat 60 N lat 45 N lat 30 N lat 15 N
Annual
50 mb 67,507 69,403 69,075 69,075 68,517 67,694
100 mb 53,084 54,085 54,088 54,567 54,600 54,281
150 mb 44,646 45,118 45,318 46,178 46,640 46,467
200 mb 38,661 38,780 39,098 40,184 40,699 40,528
250 mb 33,999 33,904 34,275 35,358 35,846 35,692
300 mb 30,066 29,934 30,302 31,260 31,716 31,578
400 mb 23,573 23,438 23,743 24,491 24,869 24,777
500 mb 18,287 18,150 18,383 18,986 19,272 19,229
700 mb 9,882 9,738 9,849 10,233 10,394 10,384
850 mb 4,780 4,652 4,708 4,941 5,033 5,016

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Last updated on 3/09/10