A highly nonlinear coupled mode of decadal variability in a mid-latitude ocean–atmosphere model
Kravtsov, Sergey K.
Dewar, William K.
Berloff, Pavel S.
McWilliams, James C.
MetadataShow full item record
This study examines mid-latitude climate variability in a model that couples turbulent oceanic and atmospheric flows through an active oceanic mixed layer. Intrinsic ocean dynamics of the inertial recirculation regions combines with nonlinear atmospheric sensitivity to sea-surface temperature (SST) anomalies to play a dominant role in the variability of the coupled system. Intrinsic low-frequency variability arises in the model atmosphere; when run in a stand-alone mode, it is characterized by irregular transitions between preferred high-latitude and less frequent low-latitude zonal-flow states. When the atmosphere is coupled to the ocean, the low-latitude state occurrences exhibit a statistically significant signal in a broad 5–15-year band. A similar signal is found in the time series of the model ocean’s energy in this coupled simulation. Accompanying uncoupled ocean-only and atmosphere-only integrations are characterized by a decrease in the decadal-band variability, relative to the coupled integration; their spectra are indistinguishable from a red spectrum. The time scale of the coupled interdecadal oscillation is set by the nonlinear adjustment of the ocean’s inertial recirculations to the high-latitude and low-latitude atmospheric forcing regimes. This adjustment involves, in turn, SST changes resulting in long-term ocean–atmosphere heat-flux anomalies that induce the atmospheric regime transitions.
Author Posting. © Elsevier B.V., 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Dynamics of Atmospheres and Oceans 43 (2007): 123-150, doi:10.1016/j.dynatmoce.2006.08.001.
Suggested CitationPreprint: Kravtsov, Sergey K., Dewar, William K., Berloff, Pavel S., McWilliams, James C., Ghil, M., "A highly nonlinear coupled mode of decadal variability in a mid-latitude ocean–atmosphere model", 2006-08-10, https://doi.org/10.1016/j.dynatmoce.2006.08.001, https://hdl.handle.net/1912/1793
Showing items related by title, author, creator and subject.
Kravtsov, Sergey K.; Dewar, William K.; Ghil, M.; McWilliams, James C.; Berloff, Pavel S. (2007-08-08)A simple heuristic model of coupled decadal ocean–atmosphere modes in middle latitudes is developed. Previous studies have treated atmospheric intrinsic variability as a linear stochastic process modified by a deterministic ...
Firing, Eric (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1978-08)A two-layer linear analytic model is used to study the response of the mid-latitude ocean to the seasonal variation of the windstress. The most important component of the response is a barotropic quasi-steady Sverdrup ...
Prieto, Rui; Tobeña Morcillo, Marta; Silva, Monica A. (2016-08)Understanding the dynamics of baleen whale distribution is essential to predict how environmental changes can affect their ecology and, in turn, ecosystem functioning. Recent work showed that mid-latitude habitats along ...