Yes, it's all of that. Tides, temperature variations, ocean surface winds, and circulation all go in to changing sea surface height, at various time scales. I

Yes, it's all of that. Tides, temperature variations, ocean surface winds, and circulation all go in to changing sea surface height, at various time scales. It amounts to order of a couple of meters, peak-to-peak, in a weekly average. Sea surface height (SSH) has been measured from space with great accuracy, using radar altimetry, since 1992. We can now also measure sea surface temperature (SST), salinity (SSS), and surface winds. The winds are knowable because wind ruffles the water surface and this changes the radar scatter properties. Therefore, somewhat surprisingly, we know more about the ocean than the land. For more: https://en.wikipedia.org/wiki/Ocean_surface_topography; https://en.wikipedia.org/wiki/Ocean_surface_topography; the data is at http://podaac.jpl.nasa.gov/CoreMeasurements http://podaac.jpl.nasa.gov/CoreMeasurements