EGU2020-16250
https://doi.org/10.5194/egusphere-egu2020-16250
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Examining the respective roles of greenhouse-gas and aerosol forcing for modes of multi-decadal variability

Andrea Dittus, Ed Hawkins, Laura Wilcox, Dan Hodson, Jon Robson, and Rowan Sutton
Andrea Dittus et al.
  • National Centre for Atmospheric Science, University of Reading, United Kingdom of Great Britain and Northern Ireland (a.j.dittus@reading.ac.uk)

The respective roles of aerosol and greenhouse-gas forcing in modulating the phasing and amplitude of large-scale modes of multi-decadal variability remain poorly understood, despite the attention that has been devoted to trying to separate the influence of forcing from internal variability in modes such as the Atlantic Multidecadal Variability and the Pacific Decadal Oscillation, for instance. However, understanding what drives multidecadal variability in these basins is imperative for improving near-term climate projections.

Here, we show how aerosol and greenhouse-gas forcing interact with internal climate variability to generate indices of multi-decadal variability in the Atlantic, using a large ensemble of historical simulations with HadGEM3-GC3.1 for the period 1850-2014, where anthropogenic aerosol emissions are scaled to sample a wide range in historical aerosol forcing. These results are complemented by early results from new stabilised warming simulations with the same climate model and analysis of future projections from models partaking in the Sixth Phase of the Coupled Model Intercomparison Project (CMIP6).

How to cite: Dittus, A., Hawkins, E., Wilcox, L., Hodson, D., Robson, J., and Sutton, R.: Examining the respective roles of greenhouse-gas and aerosol forcing for modes of multi-decadal variability , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-16250, https://doi.org/10.5194/egusphere-egu2020-16250, 2020

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