Western Equatorial Pacific Sea Surface and Subsurface Temperature and Mg/Ca Data over the last 4 million years Ford, H.L.; Ravelo, A.C. Ford, H.L. Ravelo, A.C. Sea Surface Temperature Reconstruction earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (ODP 806>LATITUDE .318333>LONGITUDE 159.361667) The Western Equatorial Pacific (WEP) warm pool, with surface temperatures >28 °C and a deep thermocline, is an important source of latent and sensible heat for the global climate system. Because the tropics are not sensitive to ice‐albedo feedbacks, the WEP's response to radiative forcing can be used to constrain a minimum estimate of Earth system sensitivity. Climate modeling of pCO2-radiative warming projections shows little change in WEP variability; here we use temperature distributions of individual surface and subsurface dwelling fossil foraminifera to evaluate past variability and possible radiative and dynamic climate forcing over the Plio-Pleistocene. We investigate WEP warm pool variability within paired glacial-interglacial (G-IG) intervals for four times: the Holocene-Last Glacial Maximum, ~2, ~3, and ~4 Ma. Our results show that these surface and subsurface temperature distributions are similar for all G-IG pairs, indicating no change in variability, even as pCO2-radiative forcing and other boundary conditions changed on G-IG timescales. Plio-Pleistocene sea surface temperature (SST) distributions are similar to those from the Holocene, indicating WEP SSTs respond to pCO2-radiative forcing and associated feedbacks. In contrast, Plio-Pleistocene subsurface temperature distributions suggest subsurface temperatures respond to changes in thermocline temperature and depth. We estimate tropical temperature sensitivity for the mid-Pliocene (~3 Ma) using our individual foraminifera SST data set and a previously published high-resolution boron isotope-based pCO2 reconstruction. We find tropical temperature sensitivity was equal to, or less than, that of the Late Pleistocene. STUDY NOTES: Provided Keywords: T. sacculifer, G. tumida, sea surface temperature, subsurface temperature NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Ford, H.L. Investigator : Ravelo, A.C. 2019-04-25 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/26670 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ford2019/ford2019-odp806.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ford2019/ford2019-odp806.txt English https://www.ncdc.noaa.gov/paleo/study/26670 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ford2019/ford2019-odp806.txt Ford, Heather L. and Ravelo, A. Christina2019Estimates of Pliocene Tropical Pacific Temperature Sensitivity to Radiative Greenhouse Gas ForcingPaleoceanography and Paleoclimatology342-1510.1029/2018PA003461 START YEAR: 3971000 cal yr BP * END YEAR: 3000 cal yr BP 159.361667 .318333 159.361667 .318333