Seasonal analysis of topex/poseidon altimeter Data Corrections

Abstract

One year of global TOPEX altimeter sea‐level and correction data were analyzed to consider the effect on the statistics of altimeter range corrections due to (1) seasonal variability. (2) removal of shallow water, (3) area and data‐density weighting, and 14) separate consideration of the equatorial region. Seasonal analysis was done to provide a better understanding of the temporal behavior of the statistics. The effects of shallow water were removed, since shallow water has different dynamics than deep water and could skew some resuts. Area and data‐density weighting was performed to keep the disproportionate amount of data available at the turning latitude from biasing the results. Finally, the equatorial region was considered separately, since equatorial conditions and dynamics are different than those at mid and high latitudes. It was determined that the statistics of each of the corrections was affected by one or more of these factors. Knowledge of these statistics should be useful in applying the corrections to future altimeter measurements. Overall, this effort should provide a better basis for using advanced filter techniques to improve altimeter sea‐level heights.