NASA-SSH Global Mean Sea Level from Simple Gridded Sea Surface Height

This file contains a time series of globally-averaged sea level change, or "global mean sea level" (GMSL) in units of centimeters. The estimate is based on satellite observations of sea surface height anomaly, measured by reference radar altimeter missions such as TOPEX/Poseidon, the Jason series, and Sentinel-6. The indicator values were calculated using NASA-SSH Simple Gridded Sea Surface Height from Standardized Reference Missions Only Version 1 https://podaac.jpl.nasa.gov/dataset/NASA_SSH_REF_SIMPLE_GRID_V1 .

GMSL was calculated as the area-weighted average over each map in the time series of Simple Gridded Sea Surface Height. Because maps are computed using 10-days of observations, but are computed once every 7 days, there is a small amount of overlap between data used to compute successive time steps. A version of the estimate smoothed over 60 days is also provided.

Expert users, please note that this estimate has NOT been adjusted for Glacial Isostatic Adjustment, to account for the slight long-term depression of the sea floor. Users who study the sea level budget will need to account for this effect in order to properly evaluate closure of the budget.

Note that occasional improvements to data quality can result in mm level change in the historical portions of this estimate. However, such changes remain small relative to the 3-5 mm uncertainty in global sea level estimates over the course of the 30+ year record (https://essd.copernicus.org/articles/11/1189/2019/)

The file with the filename "NASA_SSH_GMSL_INDICATOR.txt" is always the most up-to-date time series containing the most recent data.