Contours calculated from CMEMS/Aviso gridded sea level anomalies (SLAs) with 0.25° horizontal resolution (follow link for more details). The mean annual cycle at each location and global mean sea level have been subtracted from each daily value.
The difference between observed and predicted tides at the NOS Honolulu tide gauge can be roughly (though not exactly) accounted for by adding the anomaly in the map closest to Honolulu and the 'Convert to cm above HNL MSL' value in the lower left hand corner of the map. This value accounts for long-term sea level changes in Honolulu since the National Tidal Datum Epoch (1983–2001) over which the current value for Honolulu Mean Sea Level (HNL MSL) is defined. This is not a perfect conversion due to differences in coastal vs. open ocean sea level and the atmospheric inverted barometer effect.
Note: The satellite altimeters repeat their track every 10 days; daily resolution is achieved by interpolating in both space and time. Please interpret small-scale features in these maps with this caveat in mind.
Play, pause, and scrub through the daily sea level anomalies using the controls below the image.
Contours calculated from CMEMS/Aviso gridded sea level anomalies (SLAs) averaged during calendar months with at least 21 days of data. The SLA fields have been smoothed to have an effective horizontal resolution of about 5°. The mean annual cycle and long-term trend have been subtracted from each location. The most recent month is shown in the top left panel with time before present increasing along rows and then columns.