A simple coupled model of tropical Atlantic decadal climate variability

LDEO Publication: 
Publication Type  Journal Article
Year of Publication  2002
Authors  Kushnir, Y.; Seager, R.; Miller, J.; Chiang, J. C. H.
Journal Title  Geophysical Research Letters
Volume  29
Issue  23
Pages  -
Journal Date  Dec 13
ISBN Number  0094-8276
Accession Number  ISI:000181097000005
LDEO Publication Number  6371
Key Words  ocean-atmosphere model; surface-temperature; northeast brazil; circulation; rainfall

[1] A linear, zonally averaged model of the interaction between the tropical Atlantic (TA) atmosphere and ocean is presented. A balance between evaporation and meridional heat advection in the mixed layer determines the sea surface temperature tendency. The atmosphere is a fixed-depth, sub-cloud layer in which the specific humidity anomaly is determined by a steady-state balance between evaporation, meridional advection, and a parameterized humidity exchange with the free atmosphere. When the model is integrated, forced with observed surface wind anomalies from 1965 to the present, its simulation of the observed sea surface temperature (SST) is realistic and comparable to a simulation with a full ocean GCM. A statistical representation of surface winds and their relationship to the SST gradient across the equator is used to formulate and test a coupled model of their regional variability. Forced on both sides of the equator, in the trade-wind regions, with "white-noise'' windspeed perturbations, the SST-wind relationship in the near-equatorial region feeds back positively on existing SST anomalies and gives rise to decadal variability.


647MQTimes Cited:11Cited References Count:18

URL  <Go to ISI>://000181097000005
DOI  Doi 10.1029/2002gl015874