Monitoring Northern-Hemisphere stratospheric vortex fluctuations and tropospheric coupling

Downward propagation of Stratospheric Vortex Weakening events

We evaluate the downward propagation of circulation anomalies from the stratosphere to the troposphere during major fluctuations in the strength of the stratospheric polar vortex. We are using the Northern Annular Mode (NAM) index to detect anomalously weak polar vortex in the stratosphere (negative NAM). The NAM can also be used to evaluate downward coupling. The following graphs are updated daily and show the NAM index for the past 365 days using NCEP/NCAR reanalysis. Please refer to [1, 2] for detailed methodology for computing annular modes index. Other relevant references for the NAM index include [3, 4, 5, 6]

[1] [doi] P. Martineau and S. Son, “Quality of reanalysis data during stratospheric vortex weakening and intensification events,” Geophys. res. lett., vol. 37, iss. L22801, 2010.
[Bibtex]
@article{Martineau2010,
author = {Martineau, Patrick and Son, Seok-Woo},
doi = {10.1029/2010GL045237},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop//Martineau, Son - 2010.pdf:pdf},
journal = {Geophys. Res. Lett.},
number = {L22801},
title = {{Quality of reanalysis data during stratospheric vortex weakening and intensification events}},
volume = {37},
year = {2010}
}
[2] [doi] P. Martineau and S. Son, “Planetary-scale wave activity as a source of varying tropospheric response to stratospheric sudden warming events: A case study,” J. geophys. res. atmos., 2013.
[Bibtex]
@article{Martineau2013,
author = {Martineau, Patrick and Son, Seok-woo},
doi = {10.1002/jgrd.50871},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop/Martineau, Son - 2013.pdf:pdf},
issn = {2169897X},
journal = {J. Geophys. Res. Atmos.},
month = oct,
title = {{Planetary-scale wave activity as a source of varying tropospheric response to stratospheric sudden warming events: A case study}},
url = {http://doi.wiley.com/10.1002/jgrd.50871},
year = {2013}
}
[3] M. P. Baldwin and T. J. Dunkerton, “Propagation of the Arctic Oscillation from the stratosphere to the troposphere,” J. geophys. res., vol. 104, p. 30,930–937,946, 1999.
[Bibtex]
@article{Baldwin1999,
author = {Baldwin, Mark P and Dunkerton, Timothy J},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop//Baldwin, Dunkerton - 1999.pdf:pdf},
journal = {J. Geophys. Res.},
pages = {30,930--937,946},
title = {{Propagation of the Arctic Oscillation from the stratosphere to the troposphere}},
volume = {104},
year = {1999}
}
[4] D. W. J. Thompson and J. M. Wallace, “Annular Modes in the Extratropical Circulation. Part I: Month-to-Month Variability,” J. climate, vol. 13, pp. 1000-1016, 2000.
[Bibtex]
@article{Thompson2000,
author = {Thompson, David W J and Wallace, John M},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop/Thompson, Wallace - 2000.pdf:pdf},
journal = {J. Climate},
pages = {1000--1016},
title = {{Annular Modes in the Extratropical Circulation. Part I: Month-to-Month Variability}},
volume = {13},
year = {2000}
}
[5] D. W. J. Thompson, M. P. Baldwin, and J. M. Wallace, “Stratospheric Connection to Northern Hemisphere Wintertime Weather : Implications for Prediction,” J. climate, vol. 15, pp. 1421-1428, 2002.
[Bibtex]
@article{Thompson2002,
author = {Thompson, David W J and Baldwin, Mark P and Wallace, John M},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop/Thompson, Baldwin, Wallace - 2002.pdf:pdf},
journal = {J. Climate},
pages = {1421--1428},
title = {{Stratospheric Connection to Northern Hemisphere Wintertime Weather : Implications for Prediction}},
volume = {15},
year = {2002}
}
[6] [doi] M. P. Baldwin and D. W. J. Thompson, “A Critical Comparison of Stratosphere-Troposphere Coupling Indices,” Q. j. r. mereorol. soc., vol. 135, pp. 1661-1672, 2009.
[Bibtex]
@article{Baldwin2009,
author = {Baldwin, Mark P and Thompson, David W J},
doi = {10.1002/qj.479},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop/Baldwin, Thompson - 2009.pdf:pdf},
journal = {Q. J. R. Mereorol. Soc.},
pages = {1661--1672},
title = {{A Critical Comparison of Stratosphere-Troposphere Coupling Indices}},
volume = {135},
year = {2009}
}

Northern Annular Mode (NAM) index at 10 hPa

PNG | EPS | PDF
Northern Annular Mode (NAM) index at 10 hPa

Northern Annular Mode (NAM) index at 1000 hPa

PNG | EPS | PDF
Northern Annular Mode (NAM) index at 1000 hPa

Polar cap temperature anomalies at 10 hPa

PNG | EPS | PDF
Polar cap temperature anomalies at 10 hPa

Northern Annular Mode (NAM) index from 1000 hPa to 10 hPa

PNG | EPS | PDF
Northern Annular Mode (NAM) index

Polar cap temperature anomalies from 1000 hPa to 10 hPa

PNG | EPS | PDF
Polar cap temperature

6 thoughts on “Monitoring Northern-Hemisphere stratospheric vortex fluctuations and tropospheric coupling

  1. seok-woo

    I like this site a lot! I am going to advertise your site in my presentation today at Korean Met Office.
    Many thanks for your help.

    Reply
    1. Patrick Martineau Post author

      You’re welcome, and likewise, thank you for spreading the word about this page! When the Stratospheric Sudden Warming (SSW) occurred in the beginning of January, this page got about 300 visitors in a single day. I am glad to see such interest for SSWs!

      Reply
  2. Taehyoun

    I heard your site and your research from my friends, yesterday…
    You have many stratospheric information, thanks a lot

    Reply
    1. Patrick Martineau Post author

      Thanks for your comment Taehyoun, I am glad you find some valuable information on the stratospheric vortex and sudden warming events here.

      Reply

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