posted on 2019-10-22, 14:04authored byJE Tierney, NJ Abram, KJ Anchukaitis, MN Evans, C Giry, KH Kilbourne, CP Saenger, HC Wu, J Zinke
Most annually resolved climate reconstructions of the Common Era are based on terrestrial data, making it a challenge to independently assess how recent climate changes have affected the oceans. Here as part of the Past Global Changes Ocean2K project, we present four regionally calibrated and validated reconstructions of sea surface temperatures in the tropics, based on 57 published and publicly archived marine paleoclimate data sets derived exclusively from tropical coral archives. Validation exercises suggest that our reconstructions are interpretable for much of the past 400 years, depending on the availability of paleoclimate data within, and the reconstruction validation statistics for, each target region. Analysis of the trends in the data suggests that the Indian, western Pacific, and western Atlantic Ocean regions were cooling until modern warming began around the 1830s. The early 1800s were an exceptionally cool period in the Indo‐Pacific region, likely due to multiple large tropical volcanic eruptions occurring in the early nineteenth century. Decadal‐scale variability is a quasi‐persistent feature of all basins. Twentieth century warming associated with greenhouse gas emissions is apparent in the Indian, West Pacific, and western Atlantic Oceans, but we find no evidence that either natural or anthropogenic forcings have altered El Niño–Southern Oscillation‐related variance in tropical sea surface temperatures. Our marine‐based regional paleoclimate reconstructions serve as benchmarks against which terrestrial reconstructions as well as climate model simulations can be compared and as a basis for studying the processes by which the tropical oceans mediate climate variability and change.
Funding
We are grateful to the many scientists who made their data sets publicly available via the PANGAEA and the World Data Center for Paleoclimatology electronic archives (pangaea.de,ncdc.noaa.gov/paleo). In 2012–2013, over 75 Ocean2k volunteers constructed the paleoclimate data metadatabase from which the data set studied here was developed (http://pages-igbp.org/workinggroups/ocean2k/data). Organizational and logistical support was provided by Thorsten Kiefer, Lucien von Gunten, and Christian Telepski (PAGES‐IPO), via support from the U.S. NSF, NOAA, and the Swiss National Research Foundation. J.E.T. and K.J.A. acknowledge Woods Hole Oceanographic Institution for internal support. K.J.A. acknowledges the Frank and Lisina Hoch Endowed Fund at the Woods Hole Oceanographic Institution for support. N.J.A. is supported by an Australian Research Council QEII fellowship (DP110101161), and this research contributes to ARC Discovery Grant DP140102059. M.N.E. is supported by NSF/ATM0902794 and NSF/ATM0902715. J.Z. was supported by an Indian Ocean Marine Research Centre fellowship and an Honorary Research Fellowship by the University of the Witwatersrand. H.C.W. is supported by the Deutsche Forschungsgemeinschaft through DFG‐Research Center/Cluster of Excellence “The Ocean in the Earth System” at the University of Bremen (MARUM Fellowship). C.G. acknowledges MARUM–Center for Marine Environmental Sciences for internal support. K.H.K. is supported by NOAA grant NA11OAR4310171. This is University of Maryland Center for Environmental Science contribution 4984.
History
Citation
Paleoceanography, 2015, 30 (3), pp. 226-252 (27)
Author affiliation
/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/School of Geography, Geology and the Environment
The paleoclimate data and reconstructions associated with this manuscript are available for download at the NOAA National Climatic Data Center Paleoclimatology website: http://www.ncdc.noaa.gov/paleo/study/17955.