Monitoring Southern-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 Southern Annular Mode (SAM) index to detect anomalously weak polar vortex in the stratosphere (negative SAM). The SAM can also be used to evaluate downward coupling. The following graphs are updated daily and show the SAM index for the past 365 days using NCEP/NCAR reanalysis. Please refer to [1, 2] for detailed methodology for computing NAM 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}
}

Southern Annular Mode (SAM) index at 10 hPa

PNG | EPS | PDF
10 hPa Southern Annular Mode (SAM) index

Southern Annular Mode (SAM) index at 1000 hPa

PNG | EPS | PDF
10 hPa Southern Annular Mode (SAM) index

Polar cap temperature at 10 hPa

PNG | EPS | PDF
10 hPa polar cap temperature

Southern Annular Mode (SAM) index from 1000 hPa to 10 hPa

PNG | EPS | PDF
Southern Annular Mode (SAM) index

Polar cap temperature from 1000 hPa to 10 hPa

PNG | EPS | PDF
Polar cap temperature

Leave a Reply

Your email address will not be published. Required fields are marked *