Asian Hydroclimate Changes and Mechanisms in the Preboreal from an Annually-laminated Stalagmite, Daoguan Cave, Southern China

• Published in: Acta geologica Sinica (Beijing) Vol. 92; no. 1; pp. 367 - 377
• Main Authors: LIU, Shushuang, LIU, Dianbing, WANG, Yongjin, ZHAO, Kan
• Format: Journal Article
• Language: English
• Published: Richmond Wiley Subscription Services, Inc 01.02.2018; College of Geography Science, Nanjing Normal University, Nanjing 210023, China
• Edition: English ed.
• Subjects: ASM; Bond Event; Climate change; Daoguan Cave; global changes; Hydroclimate; Hydrology; Oscillations; Soil; Soil moisture; the Preboreal; Tropical climate; Variability; Wavelet analysis; Windows (intervals); the Preboreal; ASM; Daoguan Cave; Bond Event; global changes
• ISSN: 1000-9515; 1755-6724
• DOI: 10.1111/1755-6724.13511

One-year-resolved and annually-counted stalagmite multi-proxies （j180, ~13C, and layer width） from Daoguan Cave, Guizhou Province revealed detailed variability regarding the Asian Summer Monsoon （ASM） and local humidity across Bond events （BE） in the PreboreaL During BEs 8 and 7, 1.5%o enrichments in jlSo values were generally consistent with high- to low-latitude climate changes. In detail, the decadal-scale minor j180 oscillations in BE8 were broadly less than the mean value, in contrast to the significant changes in local soil moisture derived from the j13C values and layer records. In the mid-BE7, jlSo variability was generally above the average level, and higher- amplitude variations were observed in the three proxy indicators. Wavelet analysis on the total jlSo time series and across the specific time windows of BEs 8 and 7 identified periodicities of about 130, 60, and 20-a, respectively. Exceptionally strong in BE7, the 60-a cycle, pervasively observed in instrumental studies, became prominent starting at 11.4 kaBP. Thus, glacial background conditions are important for suppressing the ASM intensity in BE8, while during BE7, tropical hydrological circulations were potentially actively involved. Consequently, climate internal oscillations, analogous to modern conditions, might have occurred in the distant past once the link between the tropical ocean and atmosphere was established as occurs today.