eprintid: 10195473 rev_number: 7 eprint_status: archive userid: 699 dir: disk0/10/19/54/73 datestamp: 2024-08-06 14:04:16 lastmod: 2024-08-06 14:04:16 status_changed: 2024-08-06 14:04:16 type: article metadata_visibility: show sword_depositor: 699 creators_name: Zhao, Anni creators_name: Feng, Ran creators_name: Brierley, Chris M creators_name: Zhang, Jian creators_name: Hu, Yongyun title: Aerosol uncertainties in tropical precipitation changes for the mid-Pliocene warm period ispublished: pub divisions: UCL divisions: B03 divisions: C03 divisions: F26 note: Copyright © Author(s) 2024. This work is distributed under the Creative Commons Attribution 4.0 License (https://creativecommons.org/licenses/by/4.0/). abstract: The mid-Pliocene Warm Period (mPWP, 3.3-3.0gMa) was characterised by an atmospheric CO2 concentration exceeding 400gppmv with minor changes in continental and orbital configurations. Simulations of this past climate state have improved with newer models but still show some substantial differences from proxy reconstructions. There is little information about atmospheric aerosol concentrations during the Pliocene, but previous work suggests that it could have been quite different from the modern period. Here we apply idealised aerosol scenario experiments to examine the importance of aerosol forcing on mPWP tropical precipitation and the possibility of aerosol uncertainty explaining the mismatch between reconstructions and simulations. The absence of industrial pollutants leads to further warming, especially in the Northern Hemisphere. The Intertropical Convergence Zone (ITCZ) becomes narrower and stronger and shifts northward after removal of anthropogenic aerosols. Though not affecting the location of monsoon domain boundary, removal of anthropogenic aerosol alters the amount of rainfall within the domain, increasing summer rain rate over eastern and southern Asia and western Africa. This work demonstrates that uncertainty in aerosol forcing could be the dominant driver in tropical precipitation changes during the mid-Pliocene: causing larger impacts than the changes in topography and greenhouse gases. date: 2024-05-23 date_type: published publisher: COPERNICUS GESELLSCHAFT MBH official_url: https://doi.org/10.5194/cp-20-1195-2024 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 2282806 doi: 10.5194/cp-20-1195-2024 lyricists_name: Brierley, Christopher lyricists_id: CCBBR95 actors_name: Brierley, Christopher actors_id: CCBBR95 actors_role: owner funding_acknowledgements: [National Natural Science Foundation of China]; [National Science Foundation]; [National Center for Atmospheric Research] full_text_status: public publication: Climate of the Past volume: 20 number: 5 pagerange: 1195-1211 pages: 17 issn: 1814-9324 citation: Zhao, Anni; Feng, Ran; Brierley, Chris M; Zhang, Jian; Hu, Yongyun; (2024) Aerosol uncertainties in tropical precipitation changes for the mid-Pliocene warm period. Climate of the Past , 20 (5) pp. 1195-1211. 10.5194/cp-20-1195-2024 <https://doi.org/10.5194/cp-20-1195-2024>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10195473/1/cp-20-1195-2024.pdf