IMIS | Flanders Marine Institute
 

Flanders Marine Institute

Platform for marine research

IMIS

Publications | Institutes | Persons | Datasets | Projects | Maps
[ report an error in this record ]basket (0): add | show Printer-friendly version

Interannual atmospheric variability forced by the deep equatorial Atlantic Ocean
Brandt, P.; Funk, A.; Hormann, V.; Dengler, M.; Greatbatch, R.J.; Toole, J.M. (2011). Interannual atmospheric variability forced by the deep equatorial Atlantic Ocean. Nature (Lond.) 473(7348): 497-500. https://hdl.handle.net/10.1038/nature10013
In: Nature: International Weekly Journal of Science. Nature Publishing Group: London. ISSN 0028-0836, more
Peer reviewed article  

Available in  Authors 

Keyword
    Marine

Authors  Top 
  • Brandt, P.
  • Funk, A.
  • Hormann, V.
  • Dengler, M.
  • Greatbatch, R.J.
  • Toole, J.M.

Abstract
    Climate variability in the tropical Atlantic Ocean is determined by large-scale ocean-atmosphere interactions, which particularly affect deep atmospheric convection over the ocean and surrounding continents(1). Apart from influences from the Pacific El Nino/Southern Oscillation(2) and the North Atlantic Oscillation(3), the tropical Atlantic variability is thought to be dominated by two distinct ocean-atmosphere coupled modes of variability that are characterized by meridional(4,5) and zonal(6,7) sea-surface-temperature gradients and are mainly active on decadal and interannual timescales, respectively(8,9). Here we report evidence that the intrinsic ocean dynamics of the deep equatorial Atlantic can also affect sea surface temperature, wind and rainfall in the tropical Atlantic region and constitutes a 4.5-yr climate cycle. Specifically, vertically alternating deep zonal jets of short vertical wavelength with a period of about 4.5 yr and amplitudes of more than 10 cm s(-1) are observed, in the deep Atlantic, to propagate their energy upwards, towards the surface(10,11). They are linked, at the sea surface, to equatorial zonal current anomalies and eastern Atlantic temperature anomalies that have amplitudes of about 6 cm s(-1) and 0.4 degrees C, respectively, and are associated with distinct wind and rainfall patterns. Although deep jets are also observed in the Pacific(12) and Indian(13) oceans, only the Atlantic deep jets seem to oscillate on interannual timescales. Our knowledge of the persistence and regularity of these jets is limited by the availability of high-quality data. Despite this caveat, the oscillatory behaviour can still be used to improve predictions of sea surface temperature in the tropical Atlantic. Deep-jet generation and upward energy transmission through the Equatorial Undercurrent warrant further theoretical study.

All data in IMIS is subject to the VLIZ privacy policy Top | Authors