Monsoon Responses to Climate Changes—Connecting Past, Present and Future
Purpose of Review: Knowledge of how monsoons will respond to external forcings through the twenty-first century has been confounded by incomplete theories of tropical climate and insufficient representation in climate models. This review highlights recent insights from past warm climates and historical trends that can inform our understanding of monsoon evolution in the context of an emerging energetic framework. Recent Findings: Projections consistent with paleoclimate evidence and theory indicate expanded/wetter monsoons in Africa and Asia, with continued uncertainty in the Americas. Twentieth century observations are not congruent with expectations of monsoon responses to radiative forcing from greenhouse gases, due to the confounding effect of aerosols. Lines of evidence from warm climate analogues indicate that while monsoons respond in globally coherent and predictable ways to orbital forcing and inter-hemispheric thermal gradients, there are differences in response to these forcings and also between land and ocean. Summary: Further understanding of monsoon responses to climate change will require refinement of the energetic framework to incorporate zonal asymmetries and the use of model hierarchies.
Additional Information© 2019 Springer Nature Switzerland AG. Published online: 18 March 2019. We thank the editor, Robin Chadwick, and two anonymous reviewers for constructive critiques that have shaped the structure and improved the clarity of this review. Conversations with Michela Biasutti were essential in the development of this review. We acknowledge the CESM Large Ensemble Community Project and supercomputing resources provided by NSF/CISL/Yellowstone. CMAP and GPCP precipitation data is provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado, USA, and acquired from their Web site at https://www.esrl.noaa.gov/psd/. The authors acknowledge grant support as follows: A.S. acknowledges NSF support from CAREER-1056216, S.B. acknowledges support by NSF under award AGS-1462544, S.J.C. acknowledges NOAA support from awards NA15OAR43100095, NA16OAR4310079, NA18OAR4310277, S.A.R. acknowledges support from the University of Delaware Research Foundation from award GEOG45212717000, and M.R. acknowledges Fondecyt 1171773, Nucleo Milenio PaleoClimate and FONDAP/ CONICYT 15110009. The authors declare they have no conflicts of interest.
Draft - monsoon_review.pdf