Modeling a strong East Asian summer monsoon in a globally cool Earth, the MIS-13 case

• Main Authors: Yin, Q. Z., Berger, A., Driesschaert, E., Goosse, H., Loutre, M. F., Crucifix, M.
• Other Authors: Institut d'Astronomie et de Géophysique Georges Lemaître (UCL-ASTR), Université Catholique de Louvain = Catholic University of Louvain (UCL)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; ice core; Ice Sheet
• Online Access: https://hal.science/hal-00298203; https://hal.science/hal-00298203/document; https://hal.science/hal-00298203/file/cpd-3-1261-2007.pdf

International audience Deep-sea and ice-core records show a significant reduced amplitude of the ice volume, temperature and greenhouse gases variations before Marine Isotope Stage (MIS) 11, about 400 000 years ago, with less warm (more glaciated) interglacials and less cold glacials. At the same time, the loess in northern China, the sedimentary core in the eastern Tibetan Plateau and the palaeosols in southern China all record an unusually warm and wet climate during MIS-13 (about 500 000 years ago), indicating an extremely strong East Asian summer monsoon. To understand this seeming paradox of a strong East Asian summer monsoon occurring during the cool MIS-13, a three-dimension Earth system Model of Intermediate complexity is used. Modeling results show that this very strong MIS-13 East Asian summer monsoon, identified from the precipitation, horizontal and vertical (omega) wind, and pressure (geopotential) fields, results from the astronomical and ice sheet forcings. North Hemisphere summer at perihelion both at 529 and 506 ka BP leads to an East Asian summer monsoon stronger than during the Pre-Industrial time. In addition, the ice sheets reinforce the East Asian summer monsoon through the propagation of a perturbation wave which is induced mainly by the Eurasian ice sheet and is influenced by the Tibetan Plateau.