Stochastic climate models, Part II Application to sea-surface temperature anomalies and thermocline variability

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FRANKIGNOUL, CLAUDE ; HASSELMANN, KLAUS (2011)
  • Publisher: Co-Action Publishing
  • Journal: Tellus A (issn: 1600-0870, eissn: 0280-6495)
  • Related identifiers: doi: 10.3402/tellusa.v29i4.11362
  • Subject:
    arxiv: Physics::Atmospheric and Oceanic Physics

The concept of stochastic climate models developed in Part I of this series (Hasselmann, 1976) is applied to the investigation of the low frequency variability of the upper ocean. It is shown that large-scale, long-time sea surface temperature (SST) anomalies may be explained naturally as the response of the oceanic surface layers to short-time-scale atmospheric forcing. The white-noise spectrum of the atmospheric input produces a red response spectrum, with most of the variance concentrated in very long periods. Without stabilizing negative feedback, the oceanic response would be nonstationary, the total SST variance growing indefinitely with time. With negative feedback, the response is asymptotically stationary. These effects are illustrated through numerical experiments with a very simple ocean-atmosphere model. The model reproduces the principal features and orders of magnitude of the observed SST anomalies in mid-latitudes. Independent support of the stochastic forcing model is provided by direct comparisons of observed sensible and latent heat flux spectra with SST anomaly spectra, and also by the structure of the cross correlation functions of atmospheric surface pressure and SST anomaly patterns. The numerical model is further used to simulate anomalies in the near-surface thermocline through Ekman pumping driven by the curl of the wind stress. The results suggest that short-time-scale atmospheric forcing should be regarded as a possible candidate for the origin of large-scale, low-period variability in the seasonal thermocline.DOI: 10.1111/j.2153-3490.1977.tb00740.x
  • References (38)
    38 references, page 1 of 4

    Bernstein, R. L. & White, W. B. 1974. Time and length scales of baroclinic eddies in the central North Pacific ocean. J. Phys. Oceanogr. 4,613-624.

    Bjerknes, J. 1966. A possible response of the atmospheric Hadley circulation to equatorial anomalies of ocean temperature. Tellus 28,820-828.

    Byshev, V. I. & Ivanov, Y. A. 1969. The time spectra of some characteristics of the atmosphere above the ocean. Izuestiya Akademii nauk S S S R 5,17-28.

    Chervin, R. M., Washington, W.M. & Schneider, S. H. 1976. Testing the statistical significance of the response of the NCAR General Circulation Model to North Pacific Ocean surface temperature anomalies. J. Atmos. Sciences 33.4 13-423.

    Clark, N. E. 1972. Specification of sea surface temperature anomaly patterns in the eastern North Pacific. J. Phys. Oceanogr. 2,391-404.

    Davis, R. E. 1976. Predictability of sea surface temperature and sea level pressure anomalies over the North Pacific ocean. J. Phys. Oceanogr. 6, 249- 266.

    Dantzler, H. L. Jr. 1977. Potential energy maxima in the tropical and subtropical North Atlantic. J. Phys. Oceanogr. (submitted to).

    Denman, K. L. 1973. A time-dependent model of the upper ocean. J . Phys. Oceanogr. 3, 173-184.

    Emery, W. J. 1976. The role of vertical motion in the heat budget of the upper Northeastern Pacific Ocean. J . Phys. Oceanogr. 6,299-305.

    Frost, M. R. 1975. Stress, evaporative heat flux and sensible heat flux distributions of the North Atlantic (mid-latitude) and their contribution to the production of large scale sea surface temperature anomalies, Master thesis, Southampton University.

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