Eccentricity-paced monsoon variability on the northeastern Tibetan Plateau in the Late Oligocene high CO ₂ world

Abstract

Precipitation on the NE Tibetan Plateau was driven by combined high- and low-latitude processes during the warm Late Oligocene.

Oligocene moisture variations as evidenced by an aeolian dust sequence in Inner Mongolia, China

“…The possible increase in temperatures during this period and a simultaneous strengthening of summer monsoonal circulation would be expected, since continental summer temperatures govern moist static energy, which in turn controls monsoonal intensity 95 . Therefore, the variability in MAP and weathering intensity in the upper part of the Ulantatal sequence may have originated from the EASM, driven by astronomically forced Antarctic ice sheet oscillations 96 . This is also corroborated by the coupling of aridity events in Ulantatal with the marine oxygen isotope events.…”

Orbital Forcing of Climatic Changes on the Central Tibetan Plateau Reveals Late Oligocene to Early Miocene South Asian Monsoon Evolution

“…Periodic expansion and contraction of the ice sheet could result in periodic variability of sea level, sea surface temperature, intermediate and deep‐water production in the Southern Ocean, and amount of latent heat release (Ao et al., 2021; Nie et al., 2017). These processes further regulate the orbital‐scale changes of the capacity of the monsoon to transport moisture, such as tropical ocean water evaporation and lower‐tropospheric water vapor content affected by temperature, distance of moisture transport pathway from the ocean to the studied areas affected by sea‐level fluctuations and coastline, finally leading to orbital‐scale changes of intensity, northeastern edge, and precipitation extent of the SAM in the central TP (Ao et al., 2021; Nie et al., 2017). Alternatively, eccentricity modulates low‐latitude summer insolation via nonlinear interaction with the global carbon cycle could also be a factor that forces the SAM in the Lunpola Basin (Ao et al., 2021).…”

“…These processes further regulate the orbital‐scale changes of the capacity of the monsoon to transport moisture, such as tropical ocean water evaporation and lower‐tropospheric water vapor content affected by temperature, distance of moisture transport pathway from the ocean to the studied areas affected by sea‐level fluctuations and coastline, finally leading to orbital‐scale changes of intensity, northeastern edge, and precipitation extent of the SAM in the central TP (Ao et al., 2021; Nie et al., 2017). Alternatively, eccentricity modulates low‐latitude summer insolation via nonlinear interaction with the global carbon cycle could also be a factor that forces the SAM in the Lunpola Basin (Ao et al., 2021). Precession affects the seasonal cycle of incoming solar radiation and contributes to mid‐ to low‐latitude summer insolation on both hemispheric distributions, and is therefore considered a major control on changes in monsoon intensity (Mohtadi et al., 2016; Thomson et al., 2021).…”

“…Cenozoic TP uplift has been documented to significantly influence northern hemisphere atmospheric circulation (Boos & Kuang, 2010; Ramstein et al., 1997; Raymo & Ruddiman, 1992; Ruddiman & Kutzbach, 1989). In addition, eccentricity paced Asian monsoon was revealed since the Eocene (Ao, et al., 2020, 2021; Huang & Hinnov, 2019; Nie et al., 2017; Z. Wang et al., 2021). However, these records came from the periphery of the TP.…”

Tectonic and Orbital Imprints in the Redox History of Japan Sea Since the Pliocene

“…This can be explained by the bundling of three precession cycles into a grand cycle, at the expense of the 23-ka spectral power (Liu et al, 2008). The 100-ka cycle also probably resulted from the bundling of two obliquity cycles, due to the weak and/or absent 100-ka cycle in the changes of East Asian monsoon and sea level from ∼1.7 Ma to MPT (Bintanja et al, 2005;Sun et al, 2010Sun et al, , 2019, despite the 100-ka cycle has been observed in some Oligocene and Miocene monsoon and benthic oxygen-carbon isotope records (Ao et al, 2021;Holbourn et al, 2018;Nie et al, 2017). Besides, a remarkable cycle of 200-ka has been observed (Figure 4c).…”