Drier tropical and subtropical Southern Hemisphere in the mid-Pliocene Warm Period

Author(s):Show less -

Pontes, Gabriel M. ^{[1, 2]} ; Wainer, Ilana ^[1] ; Taschetto, Andrea S. ^{[2, 3]} ; Sen Gupta, Alex ^{[2, 3]} ; Abe-Ouchi, Ayako ^[4] ; Brady, Esther C. ^[5] ; Chan, Wing-Le ^[4] ; Chandan, Deepak ^[6] ; Contoux, Camille ^[7] ; Feng, Ran ^[5] ; Hunter, Stephen J. ^[8] ; Kame, Yoichi ^[9] ; Lohmann, Gerrit ^[10] ; Otto-Bliesner, Bette L. ^[5] ; Peltier, W. Richard ^[6] ; Stepanek, Christian ^[10] ; Tindall, Julia ^[8] ; Tan, Ning ^{[7, 11]} ; Zhang, Qiong ^{[12, 13]} ; Zhang, Zhongshi ^{[12, 13, 11, 14]}

Affiliation:Show less -

^[1] Univ Sao Paulo, Oceanog Inst, Sao Paulo, SP - Brazil

^[2] Univ New South Wales, Climate Change Res Ctr, Sydney, NSW - Australia

^[3] Univ New South Wales, ARC Ctr Excellence Climate Extremes, Sydney, NSW - Australia

^[4] Univ Tokyo, Ctr Earth Syst Dynam, Atmosphere & Ocean Res Inst, Tokyo - Japan

^[5] Natl Ctr Atmospher Res, Boulder, CO 80307 - USA

^[6] Univ Toronto, Dept Phys, Toronto, ON - Canada

^[7] Univ Paris Saclay, Lab Sci Climat & Environm, F-91191 Gif Sur Yvette - France

^[8] Univ Leeds, Sch Earth & Environm, Leeds, W Yorkshire - England

^[9] Univ Tsukuba, Fac Life & Environm Sci, Tsukuba, Ibaraki - Japan

^[10] Helmholtz Ctr Polar & Marine Res, Alfred Wegener Inst, Bremerhaven - Germany

^[11] Chinese Acad Sci, Inst Geol & Geophys, Key Lab Cenozo Geol & Environm, Beijing - Peoples R China

^[12] Stockholm Univ, Dept Phys Geog, Stockholm - Sweden

^[13] Stockholm Univ, Bolin Ctr Climate Res, Stockholm - Sweden

^[14] Bjerknes Ctr Climate Res, NORCE Norwegian Res Ctr, Bergen - Norway

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 10, n. 1 AUG 10 2020.
• Web of Science Citations: 0

Abstract

Thermodynamic arguments imply that global mean rainfall increases in a warmer atmosphere; however, dynamical effects may result in more significant diversity of regional precipitation change. Here we investigate rainfall changes in the mid-Pliocene Warm Period (similar to 3 Ma), a time when temperatures were 2-3 degrees C warmer than the pre-industrial era, using output from the Pliocene Model Intercomparison Projects phases 1 and 2 and sensitivity climate model experiments. In the Mid-Pliocene simulations, the higher rates of warming in the northern hemisphere create an interhemispheric temperature gradient that enhances the southward cross-equatorial energy flux by up to 48%. This intensified energy flux reorganizes the atmospheric circulation leading to a northward shift of the Inter-Tropical Convergence Zone and a weakened and poleward displaced Southern Hemisphere Subtropical Convergences Zones. These changes result in drier-than-normal Southern Hemisphere tropics and subtropics. The evaluation of the mid-Pliocene adds a constraint to possible future warmer scenarios associated with differing rates of warming between hemispheres. (AU)

• FAPESP's process: 16/23670-0 - The Mid-Pliocene South Atlantic and Southern Ocean circulations as reference for the 21st century climate
• Grantee: Gabriel Marques Pontes
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)