Approaches to identifying Dansgaard-Oeschger events in pollen records and quantitative climate reconstructions ...
The warmings associated with Dansgaard-Oeschger cycles (D-Os) during the last glacial were as fast as and of a similar magnitude to expected warming over the 21st century. Identifying these warmings in pollen records objectively may assist understanding of current and future climate change impacts....
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| Format: | Thesis |
| Language: | unknown |
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University of Reading
2024
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| Online Access: | https://dx.doi.org/10.48683/1926.00115579 https://centaur.reading.ac.uk/id/eprint/115579 |
| Summary: | The warmings associated with Dansgaard-Oeschger cycles (D-Os) during the last glacial were as fast as and of a similar magnitude to expected warming over the 21st century. Identifying these warmings in pollen records objectively may assist understanding of current and future climate change impacts. Identification of D-Os by age alone is hampered by dating uncertainties in both Greenland and pollen core age-depth models, so additional methods of identification are sought. Several statistical techniques applied directly to pollen series from the circum-Mediterranean area do not show D-Os clearly and consistently. An alternative approach using quantitative climate reconstructions made using WA-PLS and fxTWA-PLS is explored. First, the robustness of these methods is evaluated. A training set should sample a climate space which includes the target climate as comprehensively as possible. Actual distributions of taxon abundances along climate gradients often differ from the symmetrical unimodal shape assumed by ... |
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