The MLS GPH Product
Basic Information
MLS measures geopotential height (GPH) on fixed pressure surfaces.
GPH is a vertical scale like elevation, but the length of the "meter stick" varies with
the magnitude of the local gravitational acceleration, g, and so is a function of latitude
and height. GPH is commonly used in meteorological calculations because it simplifies
certain equations. Where the density contribution of water vapor to air can be neglected,
the GPH difference between two pressure surfaces is proportional to the temperature of the
slab between them, so a temperature profile and GPH on a reference pressure surface are
sufficient to determine a GPH profile. GPH contours on pressure surfaces are stream functions
for geostrophic wind.
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Map of GPH
Map from 2005d264
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How it is part of MLS Science Objectives
Changes in general circulation of the atmosphere associated with climate change will be reflected
in GPH gradients. Determination of the height of MLS pressure surfaces is also an important intermediate step in
understanding all of the other retrieved fields.
How EOS MLS measures GPH
The standard product for GPH is formed from the retrieval of a reference geopotential height for the 100 hPa surface and a hydrostatic integration of the standard product temperature profiles.
In simulations of GPH retrievals, biases in the troposphere and stratosphere are less than 50 m except in the uppermost stratosphere (1.47-1.0 hPa), where they are less than 150 m.
(map from 2005d264)
Quick Product Information for data version v2.2
- Swath Name: GPH
- Vertical Resolution: ~5km at 316-10 hPa
>8km for middle atmosphere
- Useful Range: 316-0.001 hPa
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- DAAC Short Name: ML2GPH
- Precision: +/- 35m at 316-1.0 hPa
+/- 60-100m at 0.1 to .001 hPa
- Accuracy: TBD
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Publications related to the MLS GPH data product
2008
- Schwartz, M.J., A. Lambert, G.L. Manney, W.G. Read, N.J. Livesey, L. Froidevaux, C.O. Ao, P.F. Bernath, C.D. Boone, R.E. Cofield, W.H. Daffer, B.J. Drouin, E.J. Fetzer, R.A. Fuller, R.F. Jarnot, J.H. Jiang, Y.B. Jiang, B.W. Knosp, K. Kruger, J-L.F. Li, M.G. Mlynczak, S. Pawson, J.M. Russell III, M.L. Santee, W.V. Snyder, P.C. Stek, R.P. Thurstans, A.M. Tompkins, P.A. Wagner, K.A. Walker, J.W. Waters, D.L. Wu, "Validation of the Aura Microwave Limb Sounder Temperature and Geopotential Height Measurements", vol 113, pgs. D15S11, 2008. Reprint
- Manney, G.L., K. Kruger, S. Pawson, K. Minschwaner, M.J. Schwartz, W.H. Daffer, N.J. Livesey, M.G. Mlynczak, E.E. Remsberg, J.M. Russell III, J.W. Waters, "The evolution of the stratopause during the 2006 major warming: Satellite Data and Assimilated Meteorological Analyses", vol 113, pgs. D11115, 2008. Reprint
- Sandford, D.J., M.J. Schwartz, N.J. Mitchell, "The Wintertime two-day wave the the Polar Stratosphere, Mesosphere and lower Thermosphere", vol 8, pgs. 749-755, 2008. Reprint
- Schwartz, M.J., D.E. Waliser, B. Tian, D.L. Wu, J.H. Jiang, W.G. Read, "Characterization of MJO-Related Upper-Tropospheric Hydrological Processes Using MLS", vol 35, pgs. L08812, 2008. Reprint
2006
- Cofield, R.E., P.C. Stek, "Design and field-of-view calibration of 114-660 GHz optics of the Earth Observing System Microwave Limb Sounder", vol 44, num no. 5, pgs. 1166-1181, 2006. Reprint
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