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Abstract. Paleoclimatic records provide valuable information about Holocene climate, revealing aspects of climate variability for a multitude of sites around the world. However, such data also possess limitations. Proxy networks are spatially uneven, seasonally biased, uncertain in time, and present a variety of challenges when used in concert to illustrate the complex variations of past climate. Paleoclimatic data assimilation provides one approach to reconstructing past climate that can account for the diversenature of proxy records while maintaining the physics-based covariancestructures simulated by climate models. Here, we use paleoclimate dataassimilation to create a spatially complete reconstruction of temperatureover the past 12 000 years using proxy data from the Temperature 12k database and output from transient climate model simulations. Following the last glacial period, the reconstruction shows Holocene temperatures warming to a peak near 6400 years ago followed by a slow cooling toward the present day, supporting a mid-Holocene which is at least as warm as the preindustrial. Sensitivity tests show that if proxies have an overlooked summer bias, some apparent mid-Holocene warmth could actually represent summer trends rather than annual mean trends. Regardless, the potential effects of proxy seasonal biases are insufficient to align the reconstructed global mean temperature with the warming trends seen in transient model simulations.
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A multiproxy database of western North American Holocene paleoclimate records
Abstract. Holocene climate reconstructions are useful for understanding the diversefeatures and spatial heterogeneity of past and future climate change. Herewe present a database of western North American Holocene paleoclimaterecords. The database gathers paleoclimate time series from 184 terrestrialand marine sites, including 381 individual proxy records. The records spanat least 4000 of the last 12 000 years (median duration of 10 725 years)and have been screened for resolution, chronologic control, and climatesensitivity. Records were included that reflect temperature, hydroclimate,or circulation features. The database is shared in the machine readableLinked Paleo Data (LiPD) format and includes geochronologic data forgenerating site-level time-uncertain ensembles. This publicly accessible andcurated collection of proxy paleoclimate records will have wide researchapplications, including, for example, investigations of the primary featuresof ocean–atmospheric circulation along the eastern margin of the NorthPacific and the latitudinal response of climate to orbital changes. Thedatabase is available for download at https://doi.org/10.6084/m9.figshare.12863843.v1 (Routson and McKay, 2020).
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- PAR ID:
- 10289821
- Author(s) / Creator(s):
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Date Published:
- Journal Name:
- Earth System Science Data
- Volume:
- 13
- Issue:
- 4
- ISSN:
- 1866-3516
- Page Range / eLocation ID:
- 1613 to 1632
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.5194/essd-13-1613-2021
