| dc.description.abstract | In this study, a quantitative analysis is conducted to study the Southern Ocean temperature affinities of dinocysts during the Pliocene and Pleistocene in comparison to the present day. This is done to investigate whether dinocyst species maintain consistent environmental preferences over time, thereby assessing their reliability as a proxy for temperature. Two statistical analyses were performed in Python: the k-means clustering method and the individual dinocyst species analysis. The Python script was partly adapted from the RStudio model developed by Thöle et al. (2023), which was originally designed for modern dinocyst data. Six downcore datasets, covering at total time period from 5.33 Ma until present, are distributed across the Southern Ocean both latitudinally and longitudinally, were analysed. Although results from the k-means clustering analysis vary per core, overall there is consistency in dinocyst cluster-based and proxy-based SST reconstructions. However, the agreement between temperature reconstructions diminishes substantially when dinocyst species diversity in the drilling core dataset is low. To improve the dinocyst-based proxy for temperature, better spatial coverage of modern Southern Ocean surface sediment samples and more tests from various settings and regions around Antarctica. Furthermore, the individual dinocyst species analysis highlights the dominant role of Brigantedinium spp. in shaping cluster patterns, with its relative abundance varying across different latitudes between the past and the present. This study validates this quantitative approach as a promising method for examining dinocyst temperature affinities through time. | |
