Coherent pan-Asian climatic and isotopic response to orbital forcing of tropical insolation

摘要: The oxygen-18 isotope composition of calcite in stalagmites across southern and eastern Asia are highly correlated to one another on orbital time scales: large negative excursions coincident with maxima summer insolation the subtropics Northern Hemisphere (NH). These isotopic reflect changes precipitation-weighted precipitation, δ18Op. We present results from two core experiments using an isotope-enabled climate model—the“high-insolation” “low-insolation” experiments—in which model is forced by extrema NH insolation. Compared low-insolation experiment, high-insolation features profound, large-scale pattern monsoon precipitation spanning Africa Southeast that due relative contributions temperature moisture near-surface equivalent potential θe. Under high insolation, a more rapid increase land surface early causes greatest θe (and hence precipitation) shift oceans low (such as today) be over Holocene). captures general seen caves Israel western China, including drops δ18Op Tibet (−7‰), Arabian Peninsula, northeast (−4‰). Although there Tibet, change δ18O water vapor delivered subsequently precipitated; it does not inform local amount or intensity.