Orbital forcing controlling dry time carbonate precipitation temperature over landmass in the northern mid-latitude during last 50,000 years revealed from carbonate clumped isotope thermometry

摘要

Indian Summer Monsoon is an integrated component of the global climate system. The spatial movement of ITCZ at seasonal and orbital time scales is revealed in the ensemble of terrestrial and marine records covering the last 50,000 years. We deduced an evolutionary shift in the precipitation pattern near western North America, Mediterranean and South East Asia based on the estimated water isotopic composition from the delta O-18(carbonate) and Delta(47) thermometer. Record revealed three stages of climate transition: mid-Holocene optima, Younger Dryas and Last glacial maxima. Estimated mean arid air temperature was 9-21 degrees C and 12-35 degrees C during the glacial and interglacial periods respectively. The June summer solar insolation at 65 degrees N is captured in the temperature record linked with ice volume, atmospheric CO2 levels and sea surface temperature; factors influencing the monsoon precipitation near mid-latitude region worldwide.