What version of the ERSST analysis is currently being used?
ERSST version 3b is currently used. ERSST version 3 improved upon version 2 in several ways: first, by changing the low-frequency tuning, effectively increasing the sensitivity to data prior to 1930; by internally handling sea ice calculations to increase the timeliness of the dataset; and by using satellite observations to increase data where in-situ measurements are sparse (Smith et al., 2008). In version 3b, the satellite observations were removed from the product because they were found to have introduced a bias that caused problems for many of our users. The bias was strongest in the middle and high latitude Southern Hemisphere where in-situ (ship and buoy) observations are sparse. More detailed information about the switch to version 3b.
