Temperature and Monsoon Tango in a Tropical Stalagmite: Last Glacial-Interglacial Climate Dynamics
Journal
Scientific Reports
Journal Volume
8
Journal Issue
1
Date Issued
2018
Author(s)
Carme Huguet
Joyanto Routh
Susanne Fietz
M. S. Kalpana
Prosenjit Ghosh
Augusto Mangini
Vikash Kumar
Ravi Rangarajan
Abstract
© 2018 The Author(s). High-resolution paleoclimate data on stable isotopes in a stalagmite were coupled to glycerol dialkyl glycerol tetraethers (GDGTs). The Indian Summer Monsoon (ISM) transitioned from limited rainfall during the Last Glacial Maximum (LGM) to intense precipitation during early Holocene (22 to 6 ka). This was associated with changes in stalagmite growth, abundance of branched (br) and isoprenoid (iso) GDGTs, as well as δ18O, δ13C, Sr/Ca and GDGT-derived signals providing both temperature and moisture information. The reconstructed mean annual air temperature (MAAT) of the most modern stalagmite sample at ∼19°C, matches the surface and cave MAAT, but was ∼4°C lower during LGM. Warming at the end of LGM occurred before ISM strengthened and indicate 6 ka lag consistent with sea surface temperature records. The isotope records during the Younger Dryas show rapid progressions to dry conditions and weak monsoons, but these shifts are not coupled to TEX86. Moreover, change to wetter and stronger ISM, along with warmer Holocene conditions are not continuous indicating a decoupling of local temperatures from ISM.
Publisher
Springer Nature
Type
journal article