Improved annular mode variability in a global atmospheric general circulation model with 16 km horizontal resolution

Authors

  • Erool Palipane,

    1. Department of Atmospheric, Oceanic and Earth Sciences, George Mason University, Fairfax, Virginia, USA
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  • Jian Lu,

    Corresponding author
    1. Pacific Northwest National Laboratory, Richland, Washington, USA
    • Corresponding author: J. Lu, Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA 99352, USA. (jian.lu@pnnl.gov)

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  • Gang Chen,

    1. Department of Atmospheric and Earth Sciences, Cornell University, Ithaca, New York, USA
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  • James L. Kinter III

    1. Department of Atmospheric, Oceanic and Earth Sciences, George Mason University, Fairfax, Virginia, USA
    2. Center for Ocean-Land-Atmosphere Studies, Institute of Global Environmental and Society, Fairfax, Virginia, USA
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  • The copyright line for this article was changed on 30 MAR 2015 after original online publication.

Abstract

[1] In an attempt to assess the benefit of resolving the subsynoptic to mesoscale processes, the spatial and temporal characteristics of the annular modes (AMs), in particular those related to the troposphere-stratosphere interaction, are evaluated for moderate and high horizontal resolution simulations with the European Centre for Medium-Range Weather Forecast Integrated Forecast System global atmospheric general circulation model in comparison with the reanalysis. Notably, the performance with the high horizontal resolution (T1279 truncation, ~16 km) version of the model is relatively more skillful than the moderate resolution (T159 truncation, ~125 km) on most metrics examined, including the variance of the AMs at different seasons of the year, the intrinsic e-folding time scales of the AMs, and the downward influence from the stratosphere to troposphere in the AMs. Moreover, the summer Southern Annular Mode is more persistent in the high resolution and projected to respond in a greater magnitude to climate change forcing than the moderate resolution.

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