Foraminiferal faunal estimates of paleotemperature: Circumventing the no-analog problem yields cool ice age tropics


The sensitivity of the tropics to climate change, particularly the amplitude of glacial-to-interglacial changes in sea surface temperature (SST), is one of the great controversies in paleoclimatology. Here we reassess faunal estimates of ice age SSTs, focusing on the problem of no-analog planktonic foraminiferal assemblages in the equatorial oceans that confounds both classical transfer function and modern analog methods. A new calibration strategy developed here, which uses past variability of species to define robust faunal assemblages, solves the no-analog problem and reveals ice age cooling of 5° to 6°C in the equatorial current systems of the Atlantic and eastern Pacific Oceans. Classical transfer functions underestimated temperature changes in some areas of the tropical oceans because core-top assemblages misrepresented the ice age faunal assemblages. Our finding is consistent with some geochemical estimates and model predictions of greater ice age cooling in the tropics than was inferred by Climate: Long-Range Investigation, Mapping, and Prediction (CLIMAP) [1981] and thus may help to resolve a long-standing controversy. Our new foraminiferal transfer function suggests that such cooling was limited to the equatorial current systems, however, and supports CLIMAP's inference of stability of the subtropical gyre centers.

Supplement to: Mix, Alan C; Morey, Ann E; Pisias, Nicklas G; Hostetler, Steven W (1999): Foraminiferal faunal estimates of paleotemperature: Circumventing the no-analog problem yields cool ice age tropics. Paleoceanography, 14(3), 350-359

Related Identifier IsSupplementTo
Metadata Access
Creator Mix, Alan C ORCID logo; Morey, Ann E ORCID logo; Pisias, Nicklas G; Hostetler, Steven W
Publisher PANGAEA
Publication Year 1999
Rights Creative Commons Attribution 3.0 Unported;
OpenAccess true
Resource Type Supplementary Publication Series of Datasets; Collection
Format application/zip
Size 14 datasets
Discipline Earth System Research
Spatial Coverage (-0.363W, -64.550S, 4.650E, 76.817N); South Pacific Ocean; Atlantic; Bay of Bengal; Indian Ocean; South Atlantic Ocean; East Atlantic; Eastern Equatorial Pacific; Pacific Ocean; Atlantic Ocean
Temporal Coverage Begin 1874-06-13T00:00:00Z
Temporal Coverage End 1991-05-24T06:08:00Z