T/P versus Pacific Gauges

NOAA Laboratory for Satellite Altimetry

Topex/Poseidon vs. Pacific Tide Gauges (Oct 1992 - July 2002)

Topex/Poseidon altimeter data were processed as collinear differences, and sea level time series were averaged in 4x1 (longitude x latitude) cells for each month. (These are the Topex/Poseidon Gridded Deviations described elsewhere on our web site.) The monthly altimeter deviations were compared with similar averages from Pacific island tide gauges. Both were corrected for the inverse barometer effect.

Results are shown in the table below, and a figure is provided for each island comparison. The method is described in Cheney et al., 1994. Locations given below correspond to the 4x1 cells which gave the smallest rms differences.

N Lat, E Lon Island Months rms (cm) r
-1, 266 Baltra 99 2.5 0.96
-2, 186 Canton 106 1.7 0.96
0, 202 Christmas 117 2.0 0.98
-8, 178 Funafuti 118 1.9 0.98
-10, 158 Honiara 116 4.2 0.94
1, 158 Kapinga 113 2.5 0.95
9, 170 Kwajalein 118 2.8 0.92
7, 170 Majuro 116 2.5 0.95
8, 134 Malakal 117 2.8 0.98
1, 170 Nauru 107 2.6 0.96
-9, 202 Penrhyn 118 1.8 0.95
7, 158 Ponape 118 2.0 0.98
0, 174 Tarawa 118 1.8 0.97
10, 138 Yap 118 2.2 0.98

Plots are available for each tide gauge site (gauge=blue, T/P=black):

Baltra, Canton, Christmas, Funafuti, Honiara, Kapinga, Kwajalein, Majuro, Malakal, Nauru, Penrhyn, Ponape, Tarawa, Yap.

Higher-quality postscipt versions of these plots are available on anonymous ftp.

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