The School of Earth and Atmospheric Sciences Presents Dr. Nathaniel Johnson, Princeton University
Prospects for Linking Advances in Understanding ENSO Diversity to Improved Seasonal Forecasts
Recent studies on the El Niño-Southern Oscillation (ENSO) have revealed its rich spatial and temporal diversity, underscoring that the phenomenon cannot be captured by a single spatial pattern or index. However, translating these advances into improved seasonal forecasts has remained challenging.
Here I will discuss some of these challenges as well as recent research that suggests promise for predictable variations of “ENSO flavors” and their impacts. Some flavors may have distinct wintertime impacts over North America, as the nonlinear relationship between sea surface temperature (SST) and deep convection in the eastern tropical Pacific induces nonlinearities in the El Niño teleconnection patterns.
SST pattern variations also can induce deviations from the canonical El Niño atmospheric response in the central tropical Pacific, as a zonal SST gradient pattern potentially can amplify or offset the canonical response.
Overall, the identification of these distinct flavors of ENSO provide hope to seasonal forecasters that there are sources of skill beyond the canonical ENSO pattern.