The reconstruction of sea surface temperatures in the Pacific Ocean of 18,000 B.P.

摘要: Abstract All the major microfossil groups were used to reconstruct summer and winter sea-surface temperatures of an ice-age Pacific Ocean. The use these four was necessary because varying degrees preservation siliceous carbonate-rich sediments in Pacific. Their also permits comparisons temperature estimates for samples which more than one group is preserved. standard error estimate transfer function equations this study average about ± 1.5° C estimates, 1.9° estimates. Laboratory (counting) errors result 0.6° C. Most individual using different on same agree within their pooled error. reconstructions patterns show cooling subarctic region by 4°C both August February. equatorial 2–4° cooler only season (August). Seasonality (August minus February temperatures) stronger western Subarctic Transition Zones at 18,000 B.P. it present. Such changes seasonality primarily from increased equatorward shifts frontal zones. Temperatures centers subtropical gyres are generally as warm as, or warmer than, modern temperatures. In particular, Southern Hemisphere shows little no tropical latitudes except along equator eastern boundary current. distribution biotic assemblages derived indicate intensified circulation Temperature gradients steeper currents, divergence increased. “spin-up” associated with flow appear contain waters gyre centers, rather allowing dispersal subpolar regions. These relatively may act loci low pressure systems atmosphere draw moisture away land masses.