Lei Huang , Liping Zhu , Yongsong Huang , Junbo Wang , Jianting Ju , Qingfeng Ma
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引用次数: 0
Abstract
Hydroclimate variations in the Tibetan Plateau, particularly its southeastern region, significantly influence downstream agricultural and ecological systems. However, the dynamics of these changes remain inadequately understood. In this study, we present a 28.6 thousand-year record of precipitation hydrogen isotopes (δDp) derived from sedimentary leaf wax n-alkanoic acids (C30, δDwax) from Mang Co Lake, a lake in the southeastern Tibetan Plateau. Our analysis interprets δDp as a proxy for Indian Summer Monsoon (ISM) intensity, revealing its strongest phase during both the early Holocene and 28.6–26.5 calibrated thousand years before present (Cal ka BP), as well as its weakest during the Last Glacial Maximum (LGM). We find that summer insolation is the primary driver of ISM variability on the orbital scale over the past 28.6 ka. Millennial scale δDp variability reflects interactions between the summer monsoon and the westerly jet (WJ). The δDp record reveals that in the periods of 5–3 Cal ka BP and 1–0 Cal ka BP, a weakened ISM coincided with the WJ’s prolonged residence south of the Tibetan Plateau. Abrupt cooling events due to albedo feedback of ice and snow in high latitudes are inferred to have played a critical role in modulating the atmospheric circulation patterns, including the position and intensity of the WJ and ISM. Our findings emphasize the high sensitivity of the southeastern Tibetan Plateau’s hydroclimate to global climate changes, necessitating future reconstructions with improved temporal and spatial resolution.
期刊介绍:
Catena publishes papers describing original field and laboratory investigations and reviews on geoecology and landscape evolution with emphasis on interdisciplinary aspects of soil science, hydrology and geomorphology. It aims to disseminate new knowledge and foster better understanding of the physical environment, of evolutionary sequences that have resulted in past and current landscapes, and of the natural processes that are likely to determine the fate of our terrestrial environment.
Papers within any one of the above topics are welcome provided they are of sufficiently wide interest and relevance.