Application and prospect of marine sedimentary evidence toclimate change in low-latitude processes

Based on domestic and international research, this paper preliminarily summarizes the spatial distribution and temporal changes of the Walker circulation, El Niño Southern Oscillation (ENSO), Tropical Convergence Zone (ITCZ), and other low-latitude processes in the Indo-Pacific Warm Pool (IPWP) region, as well as their research methods, and points out current problems in the research. We found that the ENSO variability gradually increased in the early Holocene and the late medieval climate anomaly period (1000–700 a BP), and then introduced the northward movement of ITCZ during the Bølling-Allerød Warm Period and the pre-Boreal period (10.3 ka BP–9.5 ka BP), and the southward movement during the Younger Dryas event (12.5–11.5 ka BP) and the North Atlantic cold period (7.5 to 5 ka BP from now). In addition, we discussed the long-term orbital period of the low-latitude process. During the LGM (Last Glacial Maximum), a southerly ITCZ frontal system appeared in the equatorial eastern Pacific Ocean; and even during the 1.65 Ma ice age, there was evidence of rapid southward movement of ITCZ. At present, there are many research methods for marine sediments. The good applications of grain size analysis, clay minerals, terrestrial dust, elements and isotopes, and foraminifera in the prediction of ENSO and ITCZ displacement in marine sediments were summarized. Finally, based on the progress of marine pollen research, it is suggested to use the response of terrestrial ecosystems to climate changes as a starting point, and conduct palynological analysis to explore the changes in low-latitude processes such as terrestrial vegetation, climate, fires, and sea-land atmospheric circulation, to clarify the evolution of the Walker circulation (ENSO) and the impact of ITCZ displacement.