Data Processing Methods
Edited: 2013-01-21
The table below describes the parameters used in computing the global mean sea level.
| Parameter | TOPEX | Jason-1 | Jason-2 |
| Time Period | 1992-12-06 to 2002-01-10 |
2002-01-15 to 2008-07-02 |
2008-07-03 to present |
| Cycles | 8-343 |
1-239 |
1-current |
| Base Data Set | MGDR-B | GDR-C | GDR-D |
| Orbit | STD0905 (Lemoine et al., 2010) | GDR | |
| Range & Corrections | |||
| Waveform Tracker | GDR | GDR MLE-4 | |
| Dry Troposphere | GDR (from ECMWF) | ||
| Wet Troposphere | TMR (Replacement Product v.1.0) |
GDR-C (Cycles 1-227); JMR Replacement Product (Cycles 228-259) | AMR (GDR) |
| Ionosphere | GDR (not smoothed) |
||
| Sea State Bias | CLS Collinear v. 2009 (Tran et al., 2010) | GDR | |
| Center of Gravity | MGDR-B | N/A |
|
| Mean Sea Surface & Corrections |
|||
| Mean Sea Surface | CLS01 |
||
| Ocean Tide & Loading Tide | GOT4.7 (Ray, 1999) | ||
| Long Period Equilibrium Tide | Cartwright & Tayler, 1971, Cartwright & Edden, 1973 | ||
| Solid Earth Tide | GDR (Cartwright & Tayler, 1971; Cartwright & Edden, 1973) | ||
| Pole Tide | GDR (Wahr, 1985) | ||
| Atmospheric Pressure (Inverted Barometer) | AVISO Dynamic Atmosphere Correction (DAC) that combines MOG2D high frequency and inverted barometer low frequency signals (Pascual et al., 2008) | ||
| Glacial Isostatic Adjustment (GIA) | -0.3 mm/yr (Peltier, 2001, 2002, 2009; Peltier & Luthcke, 2009) | ||
| Processing Corrections | |||
| Inter-Mission Bias | 88.48 mm (TOPEX to Jason-1) |
-100.82 mm (Jason-1 to Jason-2) | |
| Minimum Ocean Depth | 120 m | ||
| Outlier Removal |
anomaly greater than 2 m |
||
Global mean sea level
We chose to reference TOPEX and Jason SSH anomalies on the common ground-track to an along-track mean computed by the CLS_01 mean sea surface [1]. Each cycle of T/P and Jason data are referenced to a standard set of locations using a cross-track gradient correction. Global mean sea level was computed from the corrected SSH anomalies using a simple equal-area weighted average [2]. See our calibration paper ( "Calibration of TOPEX/Poseidon and Jason Altimeter Data to Construct a Continuous Record of Mean Sea Level Change." Marine Geodesy 27, no. 1 (2004): 79.) for more information.