Low- and high-latitude influences have shaped the evolution of the Tibetan Plateau climate over the past 1.74 million years.

In this study, we investigated the interannual and intraannual variabilities in the oxygen isotope composition (δ¹⁸O) preserved in the tree ring cellulose of Pinus taiwanensis in the lower reaches of the Yangtze River, southeast China, to explore its potential utility for precipitation reconstruction over the period of 1855–2013. Intraannual variations of tree ring cellulose δ¹⁸O show distinct annual cycles that are characterized by δ¹⁸O maxima in the early growth near the ring boundary and δ¹⁸O minima in the middle and late portions of the ring. Seasonal patterns of tree ring δ¹⁸O were influenced by August–October typhoons. The tree ring cellulose δ¹⁸O was measured in both young and old trees to test for the juvenile effect. The results revealed no significant differences in the mean values and long‐term trends in δ¹⁸O in the old and young trees. A response analysis indicated that tree ring δ¹⁸O correlated significantly with precipitation and relative humidity between May and October, and the δ¹⁸O chronology accounted for 37.4% of the actual variation in the May–October precipitation between 1951 and 2013. The extremely dry and wet years revealed by the tree ring δ¹⁸O‐based reconstructed precipitation also corresponded to actual local drought and flood events from the documentary records. Reconstructed precipitation showed significant relationship with central tropical Pacific sea surface temperature, which indicated that El Niño–Southern Oscillation (ENSO) exerted influences on May–October precipitation in the lower reaches of the Yangtze River. In addition, the relationship between ENSO and precipitation weakened between 1920 and 1940, and low variance of ENSO from 1920 to 1940 may result in the damped ENSO's influences on precipitation in southeast China.

Past intervals of warming provide the unique opportunity to observe how the East Asia monsoon precipitation response happened in a warming world. However, the available evaluations are primarily limited to the last glacial-to-interglacial warming, which has fundamental differences from the current interglacial warming, particularly in changes in ice volume. Comparative paleoclimate studies of earlier warm interglacial periods can provide more realistic analogs. Here, we present high-resolution quantitative reconstructions of temperature and precipitation from north-central China over the past 800 thousand years. We found that the average precipitation increase, estimated by the interglacial data, was only around one-half of that estimated for the glacial-to-interglacial data, which is attributed to the amplification of climate change by ice volume variations. Analysis of the interglacial data suggests an increase in monsoon precipitation of ~100 mm for a warming level of 2°C on the Chinese Loess Plateau.

The ferrimagnetic properties of soils are used to quantitatively reconstruct paleomonsoon precipitation from Chinese loess. Numerous magneto‐climofunctions have been established based on the magnetic proxies that are selectively sensitive to neoformation of fine‐grained superparamagnetic (SP) or single‐domain (SD) ferrimagnetic particles. Accumulating evidence has indicated that maghemite is the final product of the ferrimagnetic phases during pedogenesis in loessic soils. Quantitative estimates of abundance of maghemite of both SP and SD grains are therefore still required in developing magneto‐climofunctions. Here, we present detailed measurements on a suite of modern soil samples from the Chinese Loess Plateau to determine pedogenic ferrimagnetic mineralogy and to develop a new magneto‐climofunction based on a new parameter derived from the high‐temperature‐dependent magnetic susceptibility. Particle size fractionation processes combined with magnetic measurements indicate that fine‐grained SP and SD maghemite is the dominant pedogenic ferrimagnetic phases. High‐temperature‐dependent susceptibility measurements show that the thermally induced susceptibility drops between ~230 and ~400 °C during heating mainly result from the conversion of maghemite to hematite. We proposed a new parameter quantifying changes in the temperature dependence of magnetic susceptibility between 230 and 400 °C, χ_td, that captures the concentration of pedogenically formed maghemite. Results show that χ_td has a strong correlation with known quantities of maghemite in synthetic standard samples and that χ_td of modern soils correlates with modern mean annual precipitation quite well (R² = 0.82, n = 24). The established χ_td‐mean annual precipitation climofunction provides a new approach to reconstructing paleorainfall during past warm interglacials from paleosols in Chinese loess.