On the characteristics of aerosol indirect effect based on dynamic regimes in global climate models


Journal Article

© 2016 Author(s) . CC Attribution 3.0 License. Aerosol-cloud interactions continue to constitute a major source of uncertainty for the estimate of climate radiative forcing. The variation of aerosol indirect effects (AIE) in climate models is investigated across different dynamical regimes, determined by monthly mean 500 hPa vertical pressure velocity ( 500), lower-tropospheric stability (LTS) and large-scale surface precipitation rate derived from several global climate models (GCMs), with a focus on liquid water path (LWP) response to cloud condensation nuclei (CCN) concentrations. The LWP sensitivity to aerosol perturbation within dynamic regimes is found to exhibit a large spread among these GCMs. It is in regimes of strong large-scale ascent ( 500g€¯ < g€¯g'25 hPa dayg'1) and low clouds (stratocumulus and trade wind cumulus) where the models differ most. Shortwave aerosol indirect forcing is also found to differ significantly among different regimes. Shortwave aerosol indirect forcing in ascending regimes is close to that in subsidence regimes, which indicates that regimes with strong large-scale ascent are as important as stratocumulus regimes in studying AIE. It is further shown that shortwave aerosol indirect forcing over regions with high monthly large-scale surface precipitation rate (> 0.1 mm dayg'1) contributes the most to the total aerosol indirect forcing (from 64 to nearly 100 %). Results show that the uncertainty in AIE is even larger within specific dynamical regimes compared to the uncertainty in its global mean values, pointing to the need to reduce the uncertainty in AIE in different dynamical regimes.

Full Text

Duke Authors

Cited Authors

  • Zhang, S; Wang, M; J. Ghan, S; Ding, A; Wang, H; Zhang, K; Neubauer, D; Lohmann, U; Ferrachat, S; Takeamura, T; Gettelman, A; Morrison, H; Lee, Y; T. Shindell, D; G. Partridge, D; Stier, P; Kipling, Z; Fu, C

Published Date

  • March 4, 2016

Published In

Volume / Issue

  • 16 / 5

Start / End Page

  • 2765 - 2783

Electronic International Standard Serial Number (EISSN)

  • 1680-7324

International Standard Serial Number (ISSN)

  • 1680-7316

Digital Object Identifier (DOI)

  • 10.5194/acp-16-2765-2016

Citation Source

  • Scopus