1137:
855:
927:"...roughly the height above sea level of a pressure level. For example, if a station reports that the 500 mb height at its location is 5600 m, it means that the level of the atmosphere over that station at which the atmospheric pressure is 500 mb is 5600 meters above sea level. This is an estimated height based on temperature and pressure data."
698:
441:
773:
238:
537:
276:
561:
471:
300:
555:
in order to relate pressure to ambient temperature and geopotential height for measurement by barometric altimeters regardless of latitude or geometric elevation:
338:
836:
816:
796:
324:
160:
1038:
Minzner, R. A.; Reber, C. A.; Jacchia, L. G.; Huang, F. T.; Cole, A. E.; Kantor, A. J.; Keneshea, T. J.; Zimmerman, S. P.; Forbes, J. M. (May 1976).
971:
Minzner, R. A.; Reber, C. A.; Jacchia, L. G.; Huang, F. T.; Cole, A. E.; Kantor, A. J.; Keneshea, T. J.; Zimmerman, S. P.; Forbes, J. M. (May 1976).
846:, the simplification obtained by assuming a constant value of gravitational acceleration is the sole reason for defining the geopotential altitude.
1039:
972:
109:: "the unit-mass must be lifted higher at the equator than at the pole, if the same amount of work is to be performed". It is a useful concept in
547:
Geopotential height plays an important role in atmospheric and oceanographic studies. The differential form above may be substituted into the
704:
101:
is not constant, varying markedly with altitude and latitude; thus, a 1-m geopotential height difference implies a different
168:
1141:
904:) which are typically seen on upper air charts. The geopotential thickness between pressure levels – difference of the 850
1122:
1111:
1040:"NASA Technical Report R-459: Defining Constants, Equations, and Abbreviated Tables of the 1976 Standard Atmosphere"
973:"NASA Technical Report R-459: Defining Constants, Equations, and Abbreviated Tables of the 1976 Standard Atmosphere"
916:, which is faster where the contours are more closely spaced and tangential to the geopotential height contours.
859:
893:
as a vertical coordinate, and express the slopes of those pressure surfaces in terms of geopotential height.
1157:
483:
886:
896:
A plot of geopotential height for a single pressure level in the atmosphere shows the troughs and ridges (
121:; it also remains a historical convention in aeronautics as the altitude used for calibration of aircraft
1046:
1031:
979:
1162:
59:
79:
920:
870:
548:
1005:. Carnegie Institution of Washington publication. Carnegie Institution of Washington. p. 13
693:{\displaystyle {dP}={-g}\ {\rho }\ {dZ}={-g_{0}}\ {\rho }\ {dH}={\frac {-g_{0}\ P}{R\ T}}\ {dH}}
246:
1000:
818:
are ambient pressure and temperature, respectively, as functions of geopotential height, and
436:{\displaystyle {H}={\frac {\Phi }{g_{0}}}\ ={\frac {1}{g_{0}}}\int _{0}^{Z}\ g(\phi ,Z)\,dZ}
942:
890:
449:
285:
139:
8:
909:
882:
55:
27:
897:
878:
821:
801:
781:
309:
145:
98:
1078:
1002:
Dynamic
Meteorology and Hydrography: Part [1]-2, [and atlas of plates]
1118:
1107:
937:
901:
843:
122:
102:
913:
474:
83:
75:
950:, a similar quantity used in geodesy, based on a slightly different gravity value
947:
106:
51:
43:
35:
332:
may be obtained from normalizing geopotential by the acceleration of gravity:
1151:
905:
552:
1117:
Eskinazi, S. "Fluid
Mechanics and Thermodynamics of our Environment", 1975.
877:
along a constant-pressure surface, because then it has the properties of a
874:
839:
134:
118:
94:
47:
39:
996:
912:
in that layer. Geopotential height contours can be used to calculate the
114:
110:
908:
and 1000 hPa geopotential heights for example – is proportional to mean
866:
869:
sciences such as meteorology often prefer to express the horizontal
303:
71:
63:
279:
93:
Geopotential height differs from geometric height (as given by a
1136:
1106:
Hofmann-Wellenhof, B. and Moritz, H. "Physical
Geodesy", 2005.
854:
87:
67:
31:
768:{\displaystyle {\frac {dP}{P}}=-{\frac {g_{0}}{R\ T}}\ {dH}}
1037:
970:
233:{\displaystyle \Phi (Z)=\int _{0}^{Z}\ g(\phi ,Z)\,dZ}
824:
804:
784:
707:
564:
486:
452:
341:
312:
288:
249:
171:
148:
1067:. McGraw-Hill Science/Engineering/Math. p. 116.
1027:. McGraw-Hill Science/Engineering/Math. p. 109.
477:at mean sea level. Expressed in differential form,
989:
830:
810:
790:
767:
692:
531:
465:
435:
318:
294:
270:
232:
154:
70:implies the vertical transport of a parcel of one
1149:
542:
66:, a geopotential height difference of one
426:
223:
1083:NOAA's National Weather Service Glossary
1062:
1022:
995:
853:
82:), it corresponds to a constant work or
532:{\displaystyle {g_{0}}\ {dH}={g}\ {dZ}}
1150:
966:
964:
16:Type of altitude above mean sea level
858:Geopotential height analysis on the
961:
13:
1100:
352:
172:
14:
1174:
1129:
1135:
923:defines geopotential height as:
1085:. NOAA National Weather Service
1071:
1056:
1016:
860:North American Mesoscale Model
423:
411:
265:
253:
220:
208:
181:
175:
140:gravitational potential energy
1:
954:
128:
326:is the geometric elevation.
7:
931:
278:is the acceleration due to
142:per unit mass at elevation
10:
1181:
271:{\displaystyle g(\phi ,Z)}
921:National Weather Service
849:
543:Role in planetary fluids
62:is assumed constant. In
46:involved in lifting one
1063:Anderson, John (2007).
1023:Anderson, John (2007).
887:weather forecast models
871:pressure gradient force
60:acceleration of gravity
54:through a hypothetical
1065:Introduction to Flight
1025:Introduction to Flight
929:
863:
832:
812:
792:
769:
694:
533:
467:
437:
320:
296:
272:
234:
156:
86:difference of 9.80665
42:) that represents the
925:
857:
842:. For the subsequent
833:
813:
793:
770:
695:
534:
468:
466:{\displaystyle g_{0}}
438:
321:
297:
295:{\displaystyle \phi }
273:
235:
157:
123:barometric altimeters
24:geopotential altitude
1158:Atmospheric dynamics
1144:at Wikimedia Commons
943:Above mean sea level
891:hydrostatic pressure
822:
802:
782:
705:
562:
549:hydrostatic equation
484:
450:
339:
310:
286:
247:
169:
146:
1142:Geopotential height
910:virtual temperature
883:primitive equations
881:. For example, the
873:as the gradient of
473:= 9.80665 m/s, the
404:
330:Geopotential height
201:
28:vertical coordinate
20:Geopotential height
879:conservative force
864:
828:
808:
788:
765:
690:
529:
463:
433:
390:
316:
292:
268:
230:
187:
152:
1163:Vertical position
1140:Media related to
938:Atmospheric model
862:(NAM) at 500 hPa.
844:definite integral
831:{\displaystyle R}
811:{\displaystyle T}
791:{\displaystyle P}
756:
752:
747:
721:
681:
677:
672:
661:
631:
623:
594:
586:
520:
501:
407:
388:
369:
365:
319:{\displaystyle Z}
204:
155:{\displaystyle Z}
103:vertical distance
1170:
1139:
1094:
1093:
1091:
1090:
1075:
1069:
1068:
1060:
1054:
1053:
1051:
1045:. Archived from
1044:
1035:
1029:
1028:
1020:
1014:
1013:
1011:
1010:
993:
987:
986:
984:
978:. Archived from
977:
968:
914:geostrophic wind
838:is the specific
837:
835:
834:
829:
817:
815:
814:
809:
797:
795:
794:
789:
774:
772:
771:
766:
764:
754:
753:
751:
745:
740:
739:
730:
722:
717:
709:
699:
697:
696:
691:
689:
679:
678:
676:
670:
665:
659:
658:
657:
644:
639:
629:
628:
621:
620:
619:
618:
602:
592:
591:
584:
583:
572:
538:
536:
535:
530:
528:
518:
517:
509:
499:
498:
497:
496:
475:standard gravity
472:
470:
469:
464:
462:
461:
442:
440:
439:
434:
405:
403:
398:
389:
387:
386:
374:
367:
366:
364:
363:
351:
346:
325:
323:
322:
317:
301:
299:
298:
293:
277:
275:
274:
269:
239:
237:
236:
231:
202:
200:
195:
161:
159:
158:
153:
84:potential energy
76:standard gravity
1180:
1179:
1173:
1172:
1171:
1169:
1168:
1167:
1148:
1147:
1132:
1103:
1101:Further reading
1098:
1097:
1088:
1086:
1077:
1076:
1072:
1061:
1057:
1049:
1042:
1036:
1032:
1021:
1017:
1008:
1006:
994:
990:
982:
975:
969:
962:
957:
934:
852:
823:
820:
819:
803:
800:
799:
783:
780:
779:
757:
741:
735:
731:
729:
710:
708:
706:
703:
702:
682:
666:
653:
649:
645:
643:
632:
624:
614:
610:
606:
595:
587:
576:
565:
563:
560:
559:
545:
521:
513:
502:
492:
488:
487:
485:
482:
481:
457:
453:
451:
448:
447:
399:
394:
382:
378:
373:
359:
355:
350:
342:
340:
337:
336:
311:
308:
307:
287:
284:
283:
248:
245:
244:
196:
191:
170:
167:
166:
147:
144:
143:
131:
99:Earth's gravity
78:value (9.80665
74:; adopting the
17:
12:
11:
5:
1178:
1177:
1166:
1165:
1160:
1146:
1145:
1131:
1130:External links
1128:
1127:
1126:
1115:
1102:
1099:
1096:
1095:
1070:
1055:
1052:on 2017-03-07.
1030:
1015:
988:
985:on 2017-03-07.
959:
958:
956:
953:
952:
951:
948:Dynamic height
945:
940:
933:
930:
851:
848:
827:
807:
787:
776:
775:
763:
760:
750:
744:
738:
734:
728:
725:
720:
716:
713:
700:
688:
685:
675:
669:
664:
656:
652:
648:
642:
638:
635:
627:
617:
613:
609:
605:
601:
598:
590:
582:
579:
575:
571:
568:
544:
541:
540:
539:
527:
524:
516:
512:
508:
505:
495:
491:
460:
456:
444:
443:
432:
429:
425:
422:
419:
416:
413:
410:
402:
397:
393:
385:
381:
377:
372:
362:
358:
354:
349:
345:
315:
291:
267:
264:
261:
258:
255:
252:
241:
240:
229:
226:
222:
219:
216:
213:
210:
207:
199:
194:
190:
186:
183:
180:
177:
174:
151:
130:
127:
107:physical space
52:unit of length
38:(assumed zero
36:mean sea level
30:referenced to
15:
9:
6:
4:
3:
2:
1176:
1175:
1164:
1161:
1159:
1156:
1155:
1153:
1143:
1138:
1134:
1133:
1124:
1123:0-12-242540-5
1120:
1116:
1113:
1112:3-211-23584-1
1109:
1105:
1104:
1084:
1080:
1074:
1066:
1059:
1048:
1041:
1034:
1026:
1019:
1004:
1003:
998:
992:
981:
974:
967:
965:
960:
949:
946:
944:
941:
939:
936:
935:
928:
924:
922:
917:
915:
911:
907:
903:
899:
894:
892:
888:
884:
880:
876:
872:
868:
861:
856:
847:
845:
841:
825:
805:
785:
761:
758:
748:
742:
736:
732:
726:
723:
718:
714:
711:
701:
686:
683:
673:
667:
662:
654:
650:
646:
640:
636:
633:
625:
615:
611:
607:
603:
599:
596:
588:
580:
577:
573:
569:
566:
558:
557:
556:
554:
553:ideal gas law
550:
525:
522:
514:
510:
506:
503:
493:
489:
480:
479:
478:
476:
458:
454:
430:
427:
420:
417:
414:
408:
400:
395:
391:
383:
379:
375:
370:
360:
356:
347:
343:
335:
334:
333:
331:
327:
313:
305:
289:
281:
262:
259:
256:
250:
227:
224:
217:
214:
211:
205:
197:
192:
188:
184:
178:
165:
164:
163:
149:
141:
137:
136:
126:
124:
120:
116:
112:
108:
104:
100:
96:
91:
89:
85:
81:
77:
73:
69:
65:
61:
58:in which the
57:
53:
49:
45:
41:
37:
33:
29:
25:
21:
1087:. Retrieved
1082:
1073:
1064:
1058:
1047:the original
1033:
1024:
1018:
1007:. Retrieved
1001:
997:Bjerknes, V.
991:
980:the original
926:
918:
895:
875:geopotential
865:
840:gas constant
777:
546:
445:
329:
328:
242:
135:Geopotential
133:
132:
119:oceanography
95:tape measure
92:
48:unit of mass
40:geopotential
23:
19:
18:
867:Geophysical
115:climatology
111:meteorology
1152:Categories
1089:2012-03-15
1009:2023-10-05
955:References
889:solve use
129:Definition
97:) because
727:−
647:−
626:ρ
608:−
589:ρ
578:−
415:ϕ
392:∫
353:Φ
290:ϕ
257:ϕ
212:ϕ
189:∫
173:Φ
50:over one
1079:"Height"
999:(1910).
932:See also
304:latitude
72:kilogram
64:SI units
280:gravity
138:is the
1121:
1110:
778:where
755:
746:
680:
671:
660:
630:
622:
593:
585:
519:
500:
446:where
406:
368:
306:, and
243:where
203:
117:, and
88:joules
1050:(PDF)
1043:(PDF)
983:(PDF)
976:(PDF)
898:highs
885:that
850:Usage
68:meter
56:space
32:Earth
26:is a
1119:ISBN
1108:ISBN
919:The
902:lows
900:and
798:and
551:and
44:work
906:hPa
302:is
105:in
90:.
80:m/s
34:'s
22:or
1154::
1081:.
963:^
282:,
162::
125:.
113:,
1125:.
1114:.
1092:.
1012:.
826:R
806:T
786:P
762:H
759:d
749:T
743:R
737:0
733:g
724:=
719:P
715:P
712:d
687:H
684:d
674:T
668:R
663:P
655:0
651:g
641:=
637:H
634:d
616:0
612:g
604:=
600:Z
597:d
581:g
574:=
570:P
567:d
526:Z
523:d
515:g
511:=
507:H
504:d
494:0
490:g
459:0
455:g
431:Z
428:d
424:)
421:Z
418:,
412:(
409:g
401:Z
396:0
384:0
380:g
376:1
371:=
361:0
357:g
348:=
344:H
314:Z
266:)
263:Z
260:,
254:(
251:g
228:Z
225:d
221:)
218:Z
215:,
209:(
206:g
198:Z
193:0
185:=
182:)
179:Z
176:(
150:Z
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.