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A Progress Report

Decadal to Century-Scale Ocean Variability and Its Effects on Terrestrial, Supramarine, and Submarine Climates. A Progress Report. Outline. Talk is itself an outline Some figures to keep you awake Proceed in a “legal” rather than a chronological order.

hedy-hoover
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A Progress Report

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  1. Decadal to Century-Scale Ocean Variability and Its Effects on Terrestrial, Supramarine, and Submarine Climates A Progress Report

  2. Outline • Talk is itself an outline • Some figures to keep you awake • Proceed in a “legal” rather than a chronological order

  3. Global Temperature Datasets and Long Period Variability • Land Surface Temperatures: NOAA NCDC Global Climate Perspectives System, 5 x 5 degree data, only to 1993 • Sea Surface Temperatures: NOAA Extended Reconstructed Sea Surface Temperature Database, 2 x 2 degree data, 1854-present, problems before 1878

  4. Spatial Patterns of Long Period Variability • EMD’d the global mean anomalies derived from each dataset • Added up the trending IMFs as trend • Removed trend from entire dataset • Added together and averaged global spatial patterns for 1/2 sigma, Positive/Negative, AMO/PDO • Apparently, my AMO convention is wrong…

  5. Points Worth Exploring Here • Insights Related to Circulation Change Within Basins and On Land • Atmospheric Bridge Effects on Other Oceans, Think Circulation Changes • Long Period Variability (in terms of mean SST) Seems Dominated by the Smaller Ocean. Why?

  6. PC/EOF/Fourier “Linear” Analysis of Local Regions • ERSST Data, Dave Camp and Xun Jiang code • Five regions of interest: Extratropical Pacific and Atlantic (generating PDO and AMO indices, looking in greater detail); Global Pacific and Atlantic (slices through whole basin…what changes?); Southern Indian Ocean (What happens here?)

  7. What’s Worth Exploring Here • Causes and Dynamics: The modes that are most significant in analyses probably connected to most detectable modes of variability; three timescales of importance (~3-7, 15-25, 50-70) • Indian Ocean trend of interest. Is it a direct signal of greenhouse forcing?

  8. EMD Analyses of PCs • What It Sounds Like: Mainly Indicates AMO Dominates Global Signal on 50-70 year timescale

  9. Reconstructed PDO Analysis • Shen et al. use strong East China rainfall correlation with PDO index to correlate back to 15th century (hmm…sardines would be nice) • EMD’d the timeseries, came up with various interesting modes: 15.5 yrs., 20-30 yrs., but the clincher is next with 50-60 vs. 100 yr. modes

  10. What’s Important Here • 58, 72-77, 102-106 yr. Modes of variability common to Pacific sardines and Northern anchovies from Santa Barbara Basin record (they anticorrelate in the recent); this analysis shows the 102-106 year mode well • Some association between century-scale mode and Little Ice Age, cold water source in Bering Sea (?), tipping points; Okhotsk (cold now, by the by).

  11. Cursory Forays into Ocean Dynamics • Why does the switch happen so quickly? • I proposed positive feedback associated with the Aleutian Low • First Step: Is there a change in the character of Pacific storminess between PDO phases?

  12. Mean Wind Events Above 23 ms^-1

  13. Mean Wind Events Above 28 ms^-1

  14. Entrainment Experiments • C. Pasquero gave me a model originally designed for nutrient transport (Price/Weller/Pinker) • Chose point in middle of Pacific, reasonably strong winds, repeat buoy data in early December, early January, early February, used NOAA Reanalysis data to force it

  15. Entrainment Experiment Wrap-Up • Horizontal Transport seems to be important even on “short” timescales • Initially thought that heavy storminess could stir up cooler water from thermocline • Entirely possible that feedback involves a change in stratification, in which the upper waters become a thin skin that is drained of heat; need better model

  16. “Better Models” • Linear Analysis of Kirtman AOGCM and UKMO IPCC Runs • Did not produce recognizable patterns of present behavior, nor did it produce correct frequency behavior, even on short-term

  17. Conclusions • At present, the work so far done really is of a motivational character rather than a minor contribution to knowledge; if something is defensible, it requires further and less desultory defense • The problems that could be tackled are potentially large and expansive • We would do better if we restricted our purview to some minor aspect that would shed some light but utilize local expertise (remote sensing and/or data analysis); and then we talk to the oceanographers…

  18. Postlude: Fishy Stories • Mantua’s Salmon Switch Between Alaskan and Cascadian fisheries • Sardines and Anchovies Out of Phase Population-Wise During 1970s-1980s transition (Japan, Peru/Chile, California) • Benguela Anchovies and Sardines Likewise Out of Phase (But Opposite in Direction) • SEAWifs + CalCOFI + Last 8 Years off California, is it possible?

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