Richardson, TB orcid.org/0000-0002-3947-9915, Samset, BH, Andrews, T et al. (2 more authors) (2016) An assessment of precipitation adjustment and feedback computation methods. Journal of Geophysical Research, 121 (19). 11,608-11,619. ISSN 0148-0227
Abstract
The precipitation adjustment and feedback framework is a useful tool for understanding global and regional precipitation changes. However, there is no definitive method for making the decomposition. In this study we highlight important differences which arise in results due to methodological choices. The responses to five different forcing agents (CO2, CH4, SO4, black carbon, and solar insolation) are analyzed using global climate model simulations. Three decomposition methods are compared: using fixed sea surface temperature experiments (fSST), regressing transient climate change after an abrupt forcing (regression), and separating based on timescale using the first year of coupled simulations (YR1). The YR1 method is found to incorporate significant SST-driven feedbacks into the adjustment and is therefore not suitable for making the decomposition. Globally, the regression and fSST methods produce generally consistent results; however, the regression values are dependent on the number of years analyzed and have considerably larger uncertainties. Regionally, there are substantial differences between methods. The pattern of change calculated using regression reverses sign in many regions as the number of years analyzed increases. This makes it difficult to establish what effects are included in the decomposition. The fSST method provides a more clear-cut separation in terms of what physical drivers are included in each component. The fSST results are less affected by methodological choices and exhibit much less variability. We find that the precipitation adjustment is weakly affected by the choice of SST climatology.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | ©2016. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
Keywords: | precipitation; rapid adjustments; feedbacks; radiative forcing; PDRMIP; climate models |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 17 Oct 2016 10:02 |
Last Modified: | 05 Oct 2017 16:07 |
Published Version: | http://dx.doi.org/10.1002/2016JD025625 |
Status: | Published |
Publisher: | American Geophysical Union |
Identification Number: | 10.1002/2016JD025625 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:106035 |