The Impact of Split and Displacement Sudden Stratospheric Warmings on the Troposphere
Name
JGR Atmospheres - 2021 - White - The Impact of Split and Displacement Sudden Stratospheric Warmings on the Troposphere.pdf
Description
Published version
Size
3.31 MB
Format
Adobe PDF
Checksum (MD5)
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Author(s)
White, Ian P
Garfinkel, Chaim I
Cohen, Judah
Jucker, Martin
Rao, Jian
Date Issued
April 1, 2021
Journal
Journal of Geophysical Research: Atmospheres
Publisher
American Geophysical Union
Citation
White, I. P., Garfinkel, C. I., Cohen, J., Jucker, M., & Rao, J. (2021). The impact of split and displacement sudden stratospheric warmings on the troposphere. Journal of Geophysical Research: Atmospheres, 126, e2020JD033989.
Version
Final published version
Abstract
Although sudden stratospheric warmings (SSWs) can improve subseasonal‐to‐seasonal forecasts, it is unclear whether the two types of SSW ‐ displacements and splits ‐ have different near‐surface effects. To examine the longer‐term (i.e., multi‐week lead) tropospheric response to displacements and splits, we utilize an intermediate‐complexity model and impose wave‐1 and wave‐2 stratospheric heating perturbations spun‐off from a control run. At longer lags, the tropospheric response is found to be insensitive to both the wavenumber and location of the imposed heating, in agreement with freely evolving displacements and splits identified in the control run. At shorter lags, however, large differences are found between displacements and splits in both the control run and the different wavenumber‐forced events. In particular, in the control run, the free‐running splits have an immediate barotropic response throughout the stratosphere and troposphere whereas displacements take 1–2 weeks before a near‐surface response becomes evident. Interestingly, this barotropic response found during CTRL splits is not captured by the barotropically forced wave‐2 events, indicating that the zonal‐mean tropospheric circulation is somehow coupled with the generation of the wave‐2 splits. It is also found that in the control run, displacements yield stronger Polar‐Cap temperature anomalies than splits, yet both still yield similar magnitude tropospheric responses. Hence, the strength of the stratospheric warming is not the only governing factor in the surface response. Overall, SSW classification based on vortex morphology may be useful for subseasonal but not seasonal tropospheric prediction.
MIT Department
Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1029/2020jd033989
