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1. Atmospheric river changes shaped mid-latitude hydroclimate since the mid-Holocene

   https://doi.org/10.1016/j.epsl.2020.116293  

   Skinner, Christopher B.; Lora, Juan M.; Payne, Ashley E.; Poulsen, Christopher J. (July 2020, Earth and Planetary Science Letters)
2. Local to Regional Hydroclimate Changes in the Tropical Andes Since the Mid-Holocene

   Konecky, B; Mauceri, A; Sae-Lim, J; Bird, B; Castañeda, I; Correa-Metrio, A; Escobar, J; Grooms, C; Hutchings, J; Michelutti, N; et al (December 2024, American Geophysical Union)

   Climate changes during the mid- to late-Holocene, after the last vestiges of glacial ice sheets dwindled, provide important context for climate change today. In the tropical Andes, most of the continuous paleoclimate records covering the late Holocene are derived from the oxygen isotope composition of ice cores, speleothems, and lake carbonates. These archives are powerful recorders of large-scale changes in circulation and monsoon intensity, but they do not necessarily capture local moisture balance, and so reconstructions of local precipitation and aridity remain scarce. Here we present contrasting histories of local effective moisture vs. regional circulation from several new biomarker records preserved in lakes and peat in the Colombian and Peruvian Andes. We focus on the hydrogen isotope composition of long-chain plant waxes, which reflects precipitation δ2H similarly to δ18O from ice cores and speleothems; and the δ13C of waxes and the δ2H of mid-chain waxes, which reflect local water stress and effective moisture. In both the Northern and Southern Hemisphere tropical Andes, fairly gradual δ2H shifts during the late Holocene indicate a progressive intensification of circulation in the South American lowlands. On the other hand, plant wax δ13C and mid-chain δ2H records indicate abrupt transitions into and out of intervals of water stress and aridity – similar to findings from pollen and sediment lithology from elsewhere in the tropical Andes. We draw on climate models and proxy data syntheses to help reconcile these curiously different accounts of effective moisture in the tropical Andes since the mid-Holocene and discuss implications for modern climate research. 

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3. A speleothem record of hydroclimate variability in northwestern Madagascar during the mid-late Holocene

   https://doi.org/10.1177/09596836231225725  

   Williams, Berry L; Burns, Stephen J; Scroxton, Nick; Godfrey, Laurie R; Tiger, Benjamin H; Yellen, Brian; Dawson, Robin R; Faina, Peterson; McGee, David; Ranivoharimanana, Lovasoa (May 2024, The Holocene)

   We present a continuous high-resolution precisely dated multiproxy record of hydroclimate variability at Anjohibe cave in northwestern Madagascar using speleothem AB13. The record spans from ~4484 y BP to ~2863 y BP. Stalagmite δ¹⁸O, δ¹³C and Sr/Ca ratios show very similar changes in hydroclimate. The mechanism controlling Sr/Ca changes, however, from prior calcite precipitation to degree of dolomite dissolution at about 4 ky BP. Our record is also in good agreement with previously published speleothem records from the same area. This agreement and multiproxy consensus indicate that AB13 provides a robust record of hydroclimate variability, including a continuous record of hydroclimate variability across the 4.2 ka event. This 4.2 ka event in Madagascar is marked by two distinct periods of drying between ~3900 y BP to 4300 y BP. A dry 4.2 ka event at this Southern Hemisphere site helps limit possible mechanisms for the event, indicating that a meridional shift to the south in the ITCZ is not responsible for the 4.2 ka event. In addition, the 4.2 ka event does not stand out as a unique dry period in our record. The longest and driest period of the record lasted ~300 years with peak dryness at ~3000 y BP. Our record differs significantly from a speleothem record from Rodrigues Island, located ~1800 km to the east of our study area in Madagascar suggesting different climatological controls on northwest Madagascar and more oceanic sites to the east. 

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4. Tropical Indian Ocean basin hydroclimate at the Mid- to Late-Holocene transition and the double drying hypothesis

   https://doi.org/10.1016/j.quascirev.2022.107837  

   Scroxton, Nick; Burns, Stephen J.; McGee, David; Godfrey, Laurie R.; Ranivoharimanana, Lovasoa; Faina, Peterson; Tiger, Benjamin H. (January 2023, Quaternary Science Reviews)
5. Hydroclimate variability in the Madagascar and Southeast African summer monsoons at the Mid- to Late-Holocene transition

   https://doi.org/10.1016/j.quascirev.2022.107874  

   Scroxton, Nick; Burns, Stephen J.; McGee, David; Godfrey, Laurie R.; Ranivoharimanana, Lovasoa; Faina, Peterson; Tiger, Benjamin H. (January 2023, Quaternary Science Reviews)