Role of an Indian Ocean Heating Dipole in ENSO Teleconnection to North Atlantic European Region
Key Findings: -
In early winter, a warm (cold) ENSO event is connected through an atmospheric bridge with positive (negative) rainfall anomalies in the western and negative (positive) anomalies in the eastern IO.
This early winter heating dipole, forced by a warm (cold) ENSO event, can set up a wave train emanating from the subtropical SAJET region that reaches NA and leads to a response that spatially projects onto the positive (negative) phase of NAO.
The IO heating dipole is partly forced as an atmospheric teleconnection by ENSO, but can also exist independently and is not related to local Indian Ocean SST forcing.
CMIP5 MME reproduces the early winter IO heating dipole response to ENSO and its transition in the NA region to some extent, but with weaker amplitude.