On the use of tide gauges to determine altimeter drift

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Abstract
TOPEX measurements of sea level variability have been compared to tide gauge measurements from 40 sites and to dynamic topography measurements computed from temperatures recorded at 23 Tropical Ocean-Global Atmosphere (TOGA)-Tropical Atmosphere-Ocean (TAO) buoys in the eastern Pacific and mean temperature-salinity profiles. Buoy data in the western Pacific were not used because of large long-term slopes in the data that appear to be due to interannual salinity variations. The relative drift between TOPEX and the two different in situ sets of data agree within 1 mmyr-1, with a weighted average of -2.6 mmyr-1 and an estimated uncertainty of 1.5 mmyr-1, if values from an internal calibration of the TOPEX altimeter are applied. The consistency of the two relative drifts suggests that the slope is due at least in part to a drift in the TOPEX measurement. A substantial portion of this drift may be due to a drift in the TOPEX microwave radiometer (TMR), since comparisons with three independent external measurements indicate a drift in sea level due to the TMR measurement of about -2 mmyr-1.
Year of Publication
1998
Journal
Journal of Geophysical Research
Volume
103
Number of Pages
12885-12890
Date Published
06/1998
URL
http://adsabs.harvard.edu/abs/1998JGR...10312885C
DOI
10.1029/98JC01197
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