Open AccessMeasurement of geopotential heights by GPS radio occultation
Author(s) -
Leroy Stephen S.
Publication year - 1997
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/96jd03083
Subject(s) - geopotential height , radio occultation , geopotential , troposphere , environmental science , stratosphere , global positioning system , climatology , meteorology , geodesy , geology , atmospheric sciences , geography , precipitation , telecommunications , computer science
Geopotential heights of constant pressure surfaces are retrieved from global positioning system (GPS) radio occultation data. In order to assess accuracy a subset of data obtained by GPS/MET during spring 1995 and summer 1995 are compared to the output of the European Centre for Medium‐Range Weather Forecasts (ECMWF) global model. The root‐mean‐square measurement error is 20 m throughout the upper troposphere and lower stratosphere. Furthermore, the ECMWF global model contains enhanced errors in the southeast Pacific. In probing the data for potential utility in climate studies, a Bayesian interpolation technique is used to map the geopotential height fields in the upper troposphere during the summer. Despite limitations of the GPS/MET data set the global average 300‐mbar geopotential height over a 2‐week period in summer 1995 is determined with an accuracy of 7 m. By obtaining greater coverage and partially resolving synoptic variability, a future constellation of 16 orbiting receivers could obtain global average geopotential height estimates in the upper troposphere with an accuracy of l m each day. Accuracy would be somewhat worse for regional studies, except in the tropics where synoptic variability is depressed.