Investigating Predictable Decadal Internal Variability in the North Atlantic Subpolar Gyre using the MPI-ESM-LR

Understanding decadal internal variability is important for studying and predicting long-term climate variability at regional and global scales. This variability can impact long-term changes in droughts and other extreme weather events, including tropical cyclone activity or extreme precipitation. Previous work has found that positive sea surface temperature (SST) anomalies in the subtropical North Atlantic can result in more predictable positive SST anomalies in the North Atlantic Subpolar Gyre (NASG) approximately 5-10 years later. This research expands upon those studies to look specifically at predictable internal variability in the North Atlantic. We analyze predictable temperatures in the NASG using the pre-industrial control run from the Max Planck Institute for Meteorology Earth System Model (MPI-ESM-LR) to examine how the North Atlantic Subpolar Gyre variability is due to internal variability. We find that the specific pattern of sea surface temperature (SST) anomalies from previous work appears to result in predictable positive SST anomalies in the NASG in the MPI-ESM control, implying a role for predictable internal variability in decadal prediction. A link to large scale variability, such as the Pacific Decadal Oscillation and the Atlantic Multi-decadal Variability, is investigated.