The Annual Peak in the SST Anomaly Spectrum

• Published in: Journal of climate Vol. 21; no. 12; pp. 2810 - 2823
• Main Authors: Möller, Jens, Dommenget, Dietmar, Semenov, Vladimir A.
• Format: Journal Article
• Language: English
• Published: Boston, MA American Meteorological Society 15.06.2008
• Subjects: Air temperature; Air-sea interaction; Annual variations; Anomalies; Atmosphere; Atmospheric models; Atmospherics; Climate change; Climate change models; Climate models; Datasets; Earth, ocean, space; Exact sciences and technology; External geophysics; General circulation models; Heat; Intergovernmental Panel on Climate Change; Marine; Meteorology; Modeling; Modelling; Ocean circulation models; Ocean currents; Ocean temperature; Oceans; Physics of the oceans; Salinity; Sea surface; Sea surface temperature; Sea surface temperature anomalies; Sea-air exchange processes; Seasonal variations; Simulation; Simulations; Statistical variance; Studies; Surface temperature; Temperature anomalies; Temperature variability; Time series; Time series models; France; United States > US; Ocean-atmosphere model; Extratropical zone; annual variations; General circulation models; Decadal variation; variance analysis; digital simulation; Sea surface temperature; ocean-atmosphere interaction; anomalies
• ISSN: 0894-8755; 1520-0442
• DOI: 10.1175/2007JCLI2025.1

The manner in which monthly mean sea surface temperature anomalies (SSTAs) show enhanced variance at the annual period in the extratropics (an annual peak in the variance spectrum) is illustrated by observations and model simulations. A mechanism, related to the reemergence of winter SST anomalies, is proposed to explain the annual peak in SST spectrum. The idea is supported by the analysis of a hierarchy of models, including Intergovernmental Panel on Climate Change model simulations. The results of the model experiments further suggest that the annual peak is either weak or absent if decadal SST variability is forced by local air–sea interaction. However, if ocean subsurface temperature variability forces decadal SST variability, the annual peak is much stronger. Strong annual peaks may therefore be seen as an indication of ocean-forced decadal SST variability in the extratropics.