@article{PageLichtDupontNivetetal.2019,
  author    = {Page, M. and Licht, A. and Dupont-Nivet, Guillaume and Meijer, Niels and Barbolini, Natasha and Hoorn, C. and Schauer, A. and Huntington, K. and Bajnai, D. and Fiebig, J. and Mulch, Andreas and Guo, Z.},
  title     = {Synchronous cooling and decline in monsoonal rainfall in northeastern Tibet during the fall into the Oligocene icehouse},
  series = {Geology},
  volume    = {47},
  journal   = {Geology},
  number    = {3},
  publisher = {American Institute of Physics},
  address   = {Boulder},
  issn      = {0091-7613},
  doi       = {10.1130/G45480.1},
  pages     = {203 -- 206},
  year      = {2019},
  abstract  = {The fall into the Oligocene icehouse is marked by a steady decline in global temperature with punctuated cooling at the Eocene-Oligocene transition, both of which are well documented in the marine realm. However, the chronology and mechanisms of cooling on land remain unclear. Here, we use clumped isotope thermometry on northeastern Tibetan continental carbonates to reconstruct a detailed Paleogene surface temperature record for the Asian continental interior, and correlate this to an enhanced pollen data set. Our results show two successive dramatic (>9 degrees C) temperature drops, at 37 Ma and at 33.5 Ma. These large-magnitude decreases in continental temperatures can only be explained by a combination of both regional cooling and shifts of the rainy season to cooler months, which we interpret to reflect a decline of monsoonal intensity. Our results suggest that the response of Asian surface temperatures and monsoonal rainfall to the steady decline of atmospheric CO2 and global temperature through the late Eocene was nonlinear and occurred in two steps separated by a period of climatic instability. Our results support the onset of the Antarctic Circumpolar Current coeval to the Oligocene isotope event 1 (Oi-1) glaciation at 33.5 Ma, reshaping the distribution of surface heat worldwide; however, the origin of the 37 Ma cooling event remains less clear.},
  language  = {en}
}
@article{LichtvanCappelleAbelsetal.2014,
  author    = {Licht, A. and van Cappelle, M. and Abels, Hemmo A. and Ladant, J. -B. and Trabucho-Alexandre, J. and France-Lanord, C. and Donnadieu, Y. and Vandenberghe, J. and Rigaudier, T. and Lecuyer, C. and Terry, D. and Adriaens, R. and Boura, A. and Guo, Z. and Soe, Aung Naing and Quade, J. and Dupont-Nivet, Guillaume and Jaeger, J. -J.},
  title     = {Asian monsoons in a late Eocene greenhouse world},
  series = {Nature : the international weekly journal of science},
  volume    = {513},
  journal   = {Nature : the international weekly journal of science},
  number    = {7519},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {0028-0836},
  doi       = {10.1038/nature13704},
  pages     = {501 -- +},
  year      = {2014},
  abstract  = {The strong present-day Asian monsoons are thought to have originated between 25 and 22 million years (Myr) ago, driven by Tibetan-Himalayan uplift. However, the existence of older Asian monsoons and their response to enhanced greenhouse conditions such as those in the Eocene period (55-34Myrago) are unknown because of the paucity of well-dated records. Here we show late Eocene climate records revealing marked monsoon-like patterns in rainfall and wind south and north of the Tibetan-Himalayan orogen. This is indicated by low oxygen isotope values with strong seasonality in gastropod shells and mammal teeth from Myanmar, and by aeolian dust deposition in northwest China. Our climate simulations support modern-like Eocene monsoonal rainfall and show that a reinforced hydrological cycle responding to enhanced greenhouse conditions counterbalanced the negative effect of lower Tibetan relief on precipitation. These strong monsoons later weakened with the global shift to icehouse conditions 34 Myr ago.},
  language  = {en}
}