Last Interglacial decadal sea surface temperature variability in the eastern Mediterranean

Abstract

The Last Interglacial (~129,000–116,000 years ago) is the most recent geologic period with a warmer-than-present climate. Proxy-based temperature reconstructions from this interval can help contextualize natural climate variability in our currently warming world, especially if they can define changes on decadal timescales. Here, we established a ~4.800-year-long record of sea surface temperature (SST) variability from the eastern Mediterranean Sea at 1–4-year resolution by applying mass spectrometry imaging of long-chain alkenones to a finely laminated organic-matter-rich sapropel deposited during the Last Interglacial. We observe the highest amplitude of decadal variability in the early stage of sapropel deposition, plausibly due to reduced vertical mixing of the highly stratified water column. With the subsequent reorganization of oceanographic conditions in the later stage of sapropel deposition, when SST forcing resembled the modern situation, we observe that the maximum amplitude of reconstructed decadal variability did not exceed the range of the recent period of warming climate. The more gradual, centennial SST trends reveal that the maximal centennial scale SST increase in our Last Interglacial record is below the projected temperature warming in the twenty-first century.

Centennial scale sequences of environmental deterioration preceded the end-Permian mass extinction

“…Additionally, a signal-to-noise ratio of 3 was applied as a filter. Analogous procedures for ensuring high-quality signals have been successfully used in previous studies of MSI 59 , 60 . Lowess smoothing of MSI data was conducted using Origin (2018) software with a span value = 0.01.…”

Improve iLOVECLIM (version 1.1) with a multi-layer snow model: surface mass balance evolution during the Last Interglacial

“…Hence, the LIG provides documented records and insights into the behaviors of different Earth system components under warm climates to benchmark models and study the dynamics behind the phenomena (Fischer et al, 2018). This period has been well-studied for various aims such as reconstructing temperature (Lunt et al, 2013;Landais et al, 2016;Obreht et al, 2022) and sea level (Kopp et al, 2013;Dutton et al, 2015); investigating climate and ice-sheet interactions (Bradley et al, 2013;Goelzer et al, 2016a;Sutter et al, 2016). Applying BESSI for the LIG has been done before in the work of Plach et al (2018) for the Greenland Ice Sheet only by using climate forcings from MAR with equilibrium runs of some LIG time slices: 130, 125, 120, and 115 kaBP.…”