Modeling the climatic implications and indicative senses of the Guliya δsup18/supO-temperature proxy record to the ocean–atmosphere system during the past 130 ka

摘要

Using an intermediate-complexity UVic Earth System Climate Model (UVicModel), the geographical and seasonal implications and indicative sensesof the Guliya temperature proxy found in the Guliya δ18O icecore record (hereinafter, the Guliya δ18O-temperature proxyrecord) are investigated under time-dependent orbital and CO₂forcings with an acceleration factor of 50 over the past 130 ka. The resultsreveal that the simulated August–September Guliya surface air temperature(SAT) reproduces the 21-ka precession and 43-ka obliquity cycles of theGuliya δ18O-temperature proxy record, showing an in-phasevariation with the latter. Moreover, the Guliya δ18O-temperature proxyrecord may be also an indicator of the August–SeptemberNorthern Hemispheric (NH) SAT. Corresponding to the difference between theextreme warm and cold phases of the precession cycle in the GuliyaAugust–September SAT, there are two anomalous patterns in SAT and seasurface temperature (SST). The first anomalous pattern shows increases ofSAT and SST toward the Arctic, which is possibly associated with an increaseof the NH incoming solar radiation that is caused by the in-phasesuperposition between the precession and obliquity cycles. The secondanomalous pattern shows increases of SAT and SST toward the equator, whichis possibly due to a decrease of incoming solar radiation over the NH polarthat results from the anti-phase counteraction between the precession andobliquity cycles. The summer (winter) Guliya and NH temperatures are higher(lower) in the warm phases of the August–September Guliya than in theircold phases. Moreover, in August–September, the Guliya SAT is closelyrelated to the North Atlantic SST, in which the Guliya precipitation mightact as a "bridge" linking the Guliya SAT and the North Atlantic SST.