Tropospheric pathways of the late-winter ENSO teleconnection to Europe
Mezzina, B.; Garcia-Serrano, J.; Ambrizzi, T.; Matei, D.; Manzini, E.; Blade, I. (2023). Tropospheric pathways of the late-winter ENSO teleconnection to Europe. Clim. Dyn. 60(11-12): 3307-3317. https://dx.doi.org/10.1007/s00382-022-06508-6 In: Climate Dynamics. Springer: Berlin; Heidelberg. ISSN 0930-7575; e-ISSN 1432-0894, more |   |
| Authors | | Top | - Mezzina, B., more
- Garcia-Serrano, J.
- Ambrizzi, T.
| - Matei, D.
- Manzini, E.
- Blade, I.
| |
| Abstract | The late-winter signal associated with the El Niño-Southern Oscillation (ENSO) over the European continent is unsettled. Two main anomalous patterns of sea-level pressure (SLP) can be identified: a “wave-like” pattern with two opposite-signed anomalies over Europe, and a pattern showing a single anomaly (“semi-isolated”). In this work, potential paths of the tropospheric ENSO teleconnection to Europe and their role in favoring a more wave-like or semi-isolated pattern are explored. Outputs from historical runs of two versions of the MPI-ESM coupled model, which simulate these two types of patterns, are examined. A novel ray-tracing approach that accounts for zonal asymmetries in the background flow is used to test potential propagation paths in these simulations and in observations; three source regions are considered: the tropical Pacific, the North America/North Atlantic, and the tropical Atlantic. The semi-isolated pattern is suggested to be related to the well-known Rossby wave train emanating from the tropical Pacific, either via a split over northern North America or via reflection due to inhomogeneities in the background flow. The wave-like pattern, in turn, appears to be related to a secondary wave train emerging from the tropical Atlantic. The competition between these two pathways contributes to determining the actual surface response. |
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