Predictability of North Atlantic Sea Surface Temperature and Upper Ocean Heat Content

AbstractUnderstanding the extent to which Atlantic sea surfaces temperatures (SST) are predictable is important due to the strong climate impacts of Atlantic SST on Atlantic hurricanes and temperature and precipitation over adjacent landmasses. However, models differ substantially on the degree of predictability of Atlantic SST and upper-ocean heat content (UOHC). In this work, a lower bound on predictability timescales for SST and UOHC in the North Atlantic is estimated purely from gridded ocean observations using a measure of the decorrelation timescale based on the local autocorrelation. Decorrelation timescales for both wintertime SST and UOHC are longest in the subpolar gyre, with maximum timescales of about 4–6 years. Wintertime SST and UOHC generally have similar decorrelation timescales, except in regions with very deep mixed layers, such as the Labrador Sea, where timescales for UOHC are much larger. Spatial variations in the wintertime climatological mixed layer depth explain 51-73% (range for 3...