Paleoclimatic conditions during Marine Isotope Stage 31 – a global database for PMIP Interglacials

Marine Isotope Stage (MIS) 31 is an interglacial period during the later part of the Early Pleistocene, which is often referred to as a super-interglacial due to the perceived strong warming in the polar regions. The new atmospheric pCO₂ stack from Nuber et al. (2025; https://doi.org/10.21203/rs.3.rs-6480074/v1) indicates levels reaching up to 285 ppm, placing MIS 31 into the same range as interglacial MIS 11c, the last interglacial MIS 5e or the Holocene. Based on the LR04 isotope stack, the timing of MIS 31 was defined as the period from 1081 to 1062 ka. However, in records from the mid-latitudinal North Atlantic, interglacial oceanographic conditions started much earlier, i.e., around 1092 ka, and the interval from 1092-1062 ka is perceived to represent MIS 31. Last year, the PMIP-Interglacials working group decided to include a MIS 31 time slice into the scenarios to be modelled. So, the database presented here aims to compile paleoclimatic and paleoecological information for the model-data comparison. Currently, the database includes 113 sites, of which 89 are from the marine environment and 13 are loess records. The sites are globally widely distributed and 45 sites provide direct temperature information either as sea-surface temperature or as lake water temperature reconstructions. After evaluating the respective age models, we will use the compiled data to produce time slice reconstructions for the early and peak interglacial phases of MIS 31.