TY - JOUR
T1 - El Nino and la Nina amplitude asymmetry caused by atmospheric feedbacks
AU - Frauen, Claudia
AU - Dommenget, Dietmar
PY - 2010
Y1 - 2010
N2 - Interannual variability of tropical Pacific sea surface temperatures (SST) has an asymmetry with
stronger positive events, El Ni??o, and weaker negative events, La Ni??a, which is generally attributed to
processes in the ocean. Here we present evidence from a new hybrid coupled model that the asymmetry
and seasonality of El Ni??o can be caused by nonlinear and seasonally varying atmospheric feedbacks.
The model consists of the ECHAM5 global atmospheric general circulation model (GCM) coupled to
the 2-dimensional El Ni??o linear recharge oscillator ocean model in the tropical Pacific and a mixed
layer ocean elsewhere. Despite the models simplistic and, by construction, linear representation of the
ocean dynamics, it is able to simulate the main statistical features of El Ni??o including period,
seasonality, skewness, and kurtosis. Analyses of the model show that a nonlinear relationship between
the zonal wind stress and SST is causing the El Ni??o-La Ni??a asymmetry.
AB - Interannual variability of tropical Pacific sea surface temperatures (SST) has an asymmetry with
stronger positive events, El Ni??o, and weaker negative events, La Ni??a, which is generally attributed to
processes in the ocean. Here we present evidence from a new hybrid coupled model that the asymmetry
and seasonality of El Ni??o can be caused by nonlinear and seasonally varying atmospheric feedbacks.
The model consists of the ECHAM5 global atmospheric general circulation model (GCM) coupled to
the 2-dimensional El Ni??o linear recharge oscillator ocean model in the tropical Pacific and a mixed
layer ocean elsewhere. Despite the models simplistic and, by construction, linear representation of the
ocean dynamics, it is able to simulate the main statistical features of El Ni??o including period,
seasonality, skewness, and kurtosis. Analyses of the model show that a nonlinear relationship between
the zonal wind stress and SST is causing the El Ni??o-La Ni??a asymmetry.
UR - http://www.scopus.com/record/display.url?eid=2-s2.0-77957596287&origin=inward&txGid=l9kwAZQzvFLnV9vIm5CqLHm%3a11
U2 - 10.1029/2010GL044444
DO - 10.1029/2010GL044444
M3 - Article
VL - 37
SP - L18801 - L18806
JO - Geophysical Research Letters
JF - Geophysical Research Letters
SN - 0094-8276
ER -