Open AccessThe Long chain Diol Index: A marine palaeotemperature proxy based on eustigmatophyte lipids that records the warmest seasons
Author(s) -
Sebastiaan W Rampen,
Thomas Friedl,
Nataliya Rybalka,
Volker Thiel
Publication year - 2022
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.2116812119
Subject(s) - proxy (statistics) , environmental science , sea surface temperature , salinity , long chain , paleoclimatology , nutrient , physical geography , oceanography , biology , ecology , chemistry , geology , climate change , geography , statistics , mathematics , polymer science
Significance Organisms adjust their lipid compositions to environmental conditions like temperature. Some adaptations involve changes in ratios between unique lipids, which can still be determined after millions of years. Analyzing such lipid ratios in ancient sediments can be used for climate reconstruction. One example is the Long chain Diol Index (LDI). The lipids, produced by unknown biological sources, occur ubiquitously in marine sediments, and the LDI correlates with temperature. However, LDI records often differ from other temperature reconstructions. We now show that a clade of eustigmatophyte algae produces these lipids, providing information on their evolutionary history. We further demonstrate that the LDI registers temperatures of the warmest months instead of annual mean temperatures, which is valuable information for climate research.