Cross-temporal meta-analysis revealed a birth cohort increase in loneliness among Chinese older adults. We conclude that changes in social connectedness and levels of health threat likely play an important role in predicting loneliness in the population of Chinese elderly adults.
Abstract. The orbital-timescale dynamics of the Quaternary Asian summer monsoons (ASM) are frequently attributed to precession-dominated northern hemispheric summer insolation. However, this long-term continuous ASM variability is inferred primarily from oxygen isotope records of stalagmites, mainly from Sanbao cave in mainland China, and may not provide a comprehensive picture of ASM evolution. A new spliced stalagmite oxygen isotope record from Yangkou cave tracks summer monsoon precipitation variation from 124 to 206 thousand years ago in Chongqing, southwest China. Our Yangkou record supports that the evolution of ASM was dominated by the North Hemisphere solar insolation on orbital timescales. When superimposed on the Sanbao record, the precipitation time series referred from Yangkou cave stalagmites supports the strong ASM periods at marine isotope stages (MIS) 6.3, 6.5, and 7.1 and weak ASM intervals at MIS 6.2, 6.4, and 7.0. This consistency confirms that ASM events affected most of mainland China. Except for the solar insolation forcing, the large amplitude of minimum δ 18 O values in Yangkou record during glacial period, such as MIS 6.5, could stem from the enhanced prevailing Pacific trade wind and/or continental shelf exposure in the Indo-Pacific warm pool.
Based on 5 high-precision 230 Th dates and 103 stable oxygen isotope ratios (δ 18 O) obtained from the top 16 mm of a stalagmite collected from Wanxiang Cave, Wudu, Gansu, variation of monsoonal precipitation in the modern Asian Monsoon (AM) marginal zone over the past 100 years was reconstructed.Comparison of the speleothem δ 18 O record with instrumental precipitation data at Wudu in the past 50 years indicates a high parallelism between the two curves, suggesting that the speleothem δ 18 O is a good proxy for the AM strength and associated precipitation, controlled by "amount effect" of the precipitation. Variation of the monsoonal precipitation during the past 100 years can be divided into three stages, increasing from AD 1875 to 1900, then decreasing from AD 1901 to 1946, and increasing again thereafter. This variation is quite similar to that of the Drought/Flooding index archived from Chinese historical documents. This speleothem-derived AM record shows a close association with the Pacific Decadal Oscillation (PDO) between AD 1875 and 1977, with higher monsoonal precipitation corresponding to cold PDO phase and vice versa at decadal timescale. The monsoonal precipitation variation is out of phase with the PDO after AD 1977, probably resulting from the decadal climate jump in the north Pacific occurring at around AD 1976/77. These results demonstrate a strong linkage between the AM and associated precipitation and the Pacific Ocean via ocean/atmosphere interaction. This relationship will aid to forecast future hydrological cycle for the AM monsoon region, and to improve forecasting potential of climatic model with observation data from cave. stalagmite from Wanxiang Cave, oxygen isotope, monsoonal strength and precipitation, western Loess Plateau, Asian summer monsoonThe Asian Monsoon (AM) is an important part of global climate system and significantly influences the climate of the AM region via an interaction among the oceanland-atmosphere systems. Previous studies [1][2][3][4] have shown that the variation of ocean-atmosphere systems in the Pacific and Indian oceans at interdecadal and interannual timescales could lead to changes in the AM circulation and associated precipitation at the same timescales. For example, Krishnan and Sugi [1] found that
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.