The PRISM project has documented patterns of sea-surface temperature (SST) and land cover using multiple proxy techniques, as well as reconstructing deep-ocean temperatures .
The interval is synonymous with the Pliocene Research Interpretation and Synoptic Mapping (PRISM) time slab for which a global dataset of palaeoenvironmental conditions has been developed by the US Geological Survey and international collaborators . According to the geological time scale of Gradstein et al. , it sits within the Piacenzian Stage of the late Pliocene. (a) The importance of the mid-Pliocene warm periodĬompared with the Pleistocene, the mPWP represents an interval of relatively warm and stable climate between 3.264 and 3.025 Ma BP . Climate model simulations indicate that proxy temperature estimates are unlikely to be significantly affected by orbital forcing for at least a precession cycle centred on the time slice, with the North Atlantic potentially being an important exception. It occurred during a period of orbital forcing that was very similar to present day. It is a warm interval characterized by a negative benthic oxygen isotope excursion (0.21–0.23‰) centred on marine isotope stage KM5c (KM5.3). A time slice centred on 3.205 Ma BP (3.204–3.207 Ma BP) has been identified as a priority for investigation. Here, we describe the rationale and approach for identifying a time slice(s) for Pliocene environmental reconstruction. This uncertainty comes, in part, from the reconstruction of a time slab rather than a time slice, where forcings required by climate models can be more adequately constrained. Uncertainties in prescribed forcings and in proxy data limit the utility of the interval to understand the dynamics of a warmer than present climate or evaluate models. While there is agreement between models and data, details of regional climate differ. The characteristics of the mid-Pliocene warm period (mPWP: 3.264–3.025 Ma BP) have been examined using geological proxies and climate models.
0 kommentar(er)
