Tropical rainfall, Rossby waves and regional winter climate predictions

By Adam A. Scaife, R. Comer, N. Dunstone, J. Knight, Doug M. Smith, C. MacLachlan, N. Martin, K. Peterson, D. Rowlands, E. Carroll and 2 more. 2017

196 citations recorded by the source corpus.

Skilful climate predictions of the winter North Atlantic Oscillation and Arctic Oscillation out to a few months ahead have recently been demonstrated, but the source of this predictability remains largely unknown. Here we investigate the role of the Tropics in this predictability. We show high levels of skill in tropical rainfall predictions, particularly over the Pacific but also the Indian and Atlantic Ocean basins. Rainfall fluctuations in these regions are associated with clear signatures in tropical and extratropical atmospheric circulation that are approximately symmetric about the Equator in boreal winter. We show how these patterns can be explained as steady poleward propagating linear Rossby waves emanating from just a few key source regions. These wave source ‘hotspots’ become more or less active as tropical rainfall varies from winter to winter but they do not change position. Finally, we show that predicted tropical rainfall explains a highly significant fraction of the predicted year‐to‐year variation of the winter North Atlantic Oscillation.

Subfields: Atmospheric Science, Global and Planetary Change, Oceanography

View Paper: https://www.semanticscholar.org/paper/a311530cc605376e4809de9be84412337c0c5eba

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atmospheric Science

1. A. Butler
2. C. Garfinkel
3. Adam A. Scaife
4. D. Domeisen
5. Hai Lin
6. T. Woollings
7. S. Ineson
8. A. Bodas‐Salcedo

In Global and Planetary Change

1. A. Butler
2. Adam A. Scaife
3. C. Garfinkel
4. D. Domeisen
5. Hai Lin
6. T. Woollings
7. S. Ineson
8. A. Bodas‐Salcedo

In Oceanography

1. A. Butler
2. C. Garfinkel
3. D. Domeisen
4. Adam A. Scaife
5. R. Wood
6. E. Maloney
7. T. Woollings
8. Hai Lin

Citations in the corpus

• The Teleconnection of El Niño Southern Oscillation to the Stratosphere (2019, background): “, regionally enhanced convection in the tropical Pacific) such as the MJO and tropical rainfall (which can also be associated with ENSO) can be used to consider possible nonlinearities of the stratospheric response to wave trains from the tropics in a far-larger sample than is currently possible wit”
• Review of Tropical‐Extratropical Teleconnections on Intraseasonal Time Scales (2017, methodology): “…of the influence of tropical-extratropical interactions on forecast skill have used reforecasts made with full GCMs (see Hamill & Kiladis, 2014; Scaife et al., 2017; Vitart & Molteni, 2010; Vitart, 2014; Wu et al., 2016 for recent examples) and re-forecasts made with statistical models, in…”
• The Met Office Global Coupled Model 3.0 and 3.1 (GC3.0 and GC3.1) Configurations (2017, background): “There is a southward displacement of the Atlantic ITCZ which, as well as affecting the Sahel, may be important for teleconnections to the midlatitudes (Scaife et al., 2017).”