EGU21-13907
https://doi.org/10.5194/egusphere-egu21-13907
EGU General Assembly 2021
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Mid-Pliocene mesic subtropical hydroclimate over continents driven by land surface changes

Ran Feng1, Tripti Bhattacharya2, Bette Otto-bliesner3, Esther Brady3, and the PlioMIP2*
Ran Feng et al.
  • 1University of Connecticut, Geosciences, Storrs, United States of America (ran.feng@uconn.edu)
  • 2Syracuse University , USA
  • 3National Center for Atmospheric Research, USA
  • *A full list of authors appears at the end of the abstract

Earth System Models (ESMs) project drying of the northern subtropics by the end of the 21st century. However, geologic evidence from intervals with elevated concentrations of atmospheric carbon dioxide (pCO2), like the mid-Pliocene, suggest mesic subtropical conditions. Several hypotheses, including an El Niño-like SST pattern and weaker Hadley circulation, have been proposed to explain this mismatch. Here, we show that PlioMIP2 ensemble broadly capture the pattern of proxy reconstructed Pliocene hydroclimate, notably a wetter Sahel and southeast Asia. Sensitivity simulations reveal that this pattern is driven by summertime rainfall increases as a result of lowered albedo and a distinct surface warming pattern, generated by prescribed vegetation and ice sheet changes. The resultant tropospheric moistening and stationary wave pattern enhance moisture convergence into the northern subtropics. Our results suggest that mid-Pliocene hydroclimate is part of the Earth system feedback to sustained CO2 concentrations similar to today.

PlioMIP2:

A. Haywood, J. Tindall, S. Hunter, A. Abe-ouchi, W. L. Chan, C. Contoux, Chuncheng Guo, Xiangyu Li, G. Lohmann, C. Stepanek, N. Tan, Q. Zhang, Z. Zhang, Charles Williams

How to cite: Feng, R., Bhattacharya, T., Otto-bliesner, B., and Brady, E. and the PlioMIP2: Mid-Pliocene mesic subtropical hydroclimate over continents driven by land surface changes, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13907, https://doi.org/10.5194/egusphere-egu21-13907, 2021.

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