Eccentricity-paced geomagnetic field and monsoon rainfall variations over the last 870 kyr

Weijian Zhou; Xianghui Kong; Greig A Paterson; Youbin Sun; Yubin Wu; Hong Ao; Feng Xian; Yajuan Du; Ling Tang; Jie Zhou; Zhengguo Shi; A J Timothy Jull; Guoqing Zhao; Zhisheng An

doi:10.1073/pnas.2211495120

Eccentricity-paced geomagnetic field and monsoon rainfall variations over the last 870 kyr

Proc Natl Acad Sci U S A. 2023 Apr 25;120(17):e2211495120. doi: 10.1073/pnas.2211495120. Epub 2023 Apr 17.

Authors

Weijian Zhou^{1

2

3}, Xianghui Kong^{1

2}, Greig A Paterson⁴, Youbin Sun^{1

5}, Yubin Wu^{2

6}, Hong Ao¹, Feng Xian^{1

2}, Yajuan Du^{1

2}, Ling Tang⁷, Jie Zhou⁷, Zhengguo Shi¹, A J Timothy Jull^{8

9}, Guoqing Zhao^{1

2}, Zhisheng An^{1

3}

Affiliations

¹ State Key Laboratory of Loess, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China.
² Shaanxi Key Laboratory of Accelerator Mass Spectrometry and Application, Xi'an Accelerator Mass Spectrometry Center, Xi'an 710061, China.
³ Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China.
⁴ Department of Earth, Ocean and Ecological Sciences, Geomagnetism Laboratory, University of Liverpool, Liverpool L69 3GP, UK.
⁵ School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
⁶ University of Chinese Academy of Sciences, Beijing 100049, China.
⁷ Xi'an Institute for Innovative Earth Environment Research, Xi'an 710061, China.
⁸ Isotope Climatology and Environmental Research Centre, Institute for Nuclear Research, Debrecen H-4026, Hungary.
⁹ University of Arizona, Tucson, AZ 85721.

Abstract

Whether there are links between geomagnetic field and Earth's orbital parameters remains unclear. Synchronous reconstructions of parallel long-term quantitative geomagnetic field and climate change records are rare. Here, we present ¹⁰Be-derived changes of both geomagnetic field and Asian monsoon (AM) rainfall over the last 870 kyr from the Xifeng loess-paleosol sequence on the central Chinese Loess Plateau. The ¹⁰Be_GM flux (a proxy for geomagnetic field-induced ¹⁰Be production rate) reveals 13 consecutive geomagnetic excursions in the Brunhes chron, which are synchronized with the global records, providing key time markers for Chinese loess-paleosol sequences. The ¹⁰Be-derived rainfall exhibits distinct ~100 kyr glacial-interglacial cycles, and superimposed precessional (~23 kyr) cycles that match with those in Chinese speleothem δ¹⁸O record. We find that changes in the geomagnetic field and AM rainfall share a common ~100 kyr cyclicity, implying a likely eccentricity modulation of both the geomagnetic field and climate.

Keywords: Asian monsoon rainfall; Chinese loess; cosmogenic 10Be; geomagnetic field; orbital eccentricity.

Abstract

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