Attending SPARC Reanalysis Intercomparison Project (S-RIP) Workshops

I will have the pleasure to attend the SPARC Reanalysis Intercomparison Project (S-RIP) Workshops held on September 10th to 12 in Maryland where I will show results of my latest project : “How well do momentum diagnostics explain extratropical stratospheric variability in reanalysis datasets?”.

The dynamical consistency of reanalysis data in terms of extratropical stratospheric variability is evaluated for 8 reanalysis datasets that include realistic stratosphere. The dynamical consistency is evaluated by computing the residue, which is the error in zonal wind tendency calculated from the resolved terms of the momentum equation…

I am looking forward to meet the S-RIP community at this meeting and exchange ideas about interesting diagnostics applicable to the inter-comparison of reanalysis datasets.

Zonal-mean data for the SPARC Reanalysis Intercomparison Project (S-RIP)

I am pleased to share zonal-mean data with the SPARC community in the context of the Reanalysis Intercomparison Project (S-RIP). 9 reanalysis data-sets are ready to serve on Charney (our computer) so why not share them with everybody?

My contribution will consist in sharing zonal-mean dynamical variables from the following reanalyses

ERA-40 [1]
ERA-Interim [2]
JRA-25 [7]
JRA-55 [8]
20CR [9]

Shared variables include, for example: wind, temperature, geopotential height, heat fluxes, momentum fluxes, etc…
Variables included are sufficient to compute detailed momentum budget either from the Eulerian-mean momentum equation or TEM momentum equation.
In addition to those variables, simple annular modes are also provided, as well as fluxes decomposed in the longitudinal wavenumber space.

Should you have any question regarding the data you can contact me at pmartineau(at)meteo(dot)mcgill(dot)ca or leave a reply on this post. Data will be available at this link.

[1] S. M. Uppala, P. W. Kallberg, A. J. Simmons, U. Andrae, D. C. V. Bechtold, M. Fiorino, J. K. Gibson, J. Haseler, A. Hernandez, G. A. Kelly, X. Li, K. Onogi, S. Saarinen, N. Sokka, R. P. Allan, E. Andersson, K. Arpe, M. A. Balmaseda, A. C. M. Beljaars, V. D. L. Berg, J. Bidlot, N. Bormann, S. Caires, F. Chevallier, A. Dethof, M. Dragosavac, M. Fisher, M. Fuentes, S. Hagemann, E. Holm, B. J. Hoskins, L. Isaken, P. A. E. M. Janssen, R. Jenne, A. P. McNally, J. -F. Mahfouf, J. -J. Morcrette, N. A. Rayner, R. W. Saunders, P. Simon, A. Sterl, K. E. Trenberth, A. Untch, D. Vasiljevic, P. Viterbo, and J. Woollen, “The \ERA-40\ re-analysis,” Q. j. r. meteorol. soc., vol. 131, pp. 2961-3012, 2005.
author = {Uppala, S M and Kallberg, P W and Simmons, A J and Andrae, U and Bechtold, V Da Costa and Fiorino, M and Gibson, J K and Haseler, J and Hernandez, A and Kelly, G A and Li, X and Onogi, K and Saarinen, S and Sokka, N and Allan, R P and Andersson, E and Arpe, K and Balmaseda, M A and Beljaars, A C M and Berg, L Van De and Bidlot, J and Bormann, N and Caires, S and Chevallier, F and Dethof, A and Dragosavac, M and Fisher, M and Fuentes, M and Hagemann, S and Holm, E and Hoskins, B J and Isaken, L and Janssen, P A E M and Jenne, R and McNally, A P and Mahfouf, J -F. and Morcrette, J -J. and Rayner, N A and Saunders, R W and Simon, P and Sterl, A and Trenberth, K E and Untch, A and Vasiljevic, D and Viterbo, P and Woollen, J},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop//Uppala et al. - 2005.pdf:pdf},
journal = {Q. J. R. Meteorol. Soc.},
pages = {2961--3012},
title = {{The \{ERA-40\} re-analysis}},
volume = {131},
year = {2005}
[2] [doi] D. P. Dee, S. M. Uppala, A. J. Simmons, P. Berrisford, P. Poli, S. Kobayashi, U. Andrae, M. A. Balmaseda, G. Balsamo, and P. Bauer, “The ERA-Interim reanalysis: configuration and performance of the data assimilation system,” Q. j. r. meteorol. soc., vol. 137, pp. 553-597, 2011.
author = {Dee, D P and Uppala, S M and Simmons, A J and Berrisford, P and Poli, P and Kobayashi, S and Andrae, U and Balmaseda, M A and Balsamo, G and Bauer, P},
doi = {10.1002/qj.828},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop/Dee et al. - 2011.pdf:pdf},
journal = {Q. J. R. Meteorol. Soc.},
pages = {553--597},
title = {{The ERA-Interim reanalysis: configuration and performance of the data assimilation system}},
volume = {137},
year = {2011}
[3] M. M. Rienecker and Coauthors, “MERRA: NASA’s Modern-Era Retrospective Analysis for Research and Applications,” J. climate, vol. 24, pp. 3624-3648, 2011.
author = {Rienecker, Michele M and Coauthors},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop/Rienecker, Coauthors - 2011.pdf:pdf},
journal = {J. Climate},
pages = {3624--3648},
title = {{MERRA: NASA’s Modern-Era Retrospective Analysis for Research and Applications}},
volume = {24},
year = {2011}
[4] E. Kalnay, M. Kanamitsu, R. Kistler, W. Collins, D. Deaven, L. Gandin, M. Iredell, S. Saha, G. White, J. Woollen, Y. Zhu, M. Chelliah, W. Ebisuzaki, W. Higgins, J. Janowiak, K. C. Mo, C. Ropelewski, J. Wang, A. Leetmaa, R. Reynolds, R. Jenne, and D. Joseph, “The \NCEP/NCAR\ 40-Year Reanalysis Project,” Bull. am. meteorol. soc., vol. 77, iss. 3, pp. 437-471, 1996.
author = {Kalnay, E and Kanamitsu, M and Kistler, R and Collins, W and Deaven, D and Gandin, L and Iredell, M and Saha, S and White, G and Woollen, J and Zhu, Y and Chelliah, M and Ebisuzaki, W and Higgins, W and Janowiak, J and Mo, K C and Ropelewski, C and Wang, J and Leetmaa, A and Reynolds, R and Jenne, Roy and Joseph, Dennis},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop/Kalnay et al. - 1996.pdf:pdf},
journal = {Bull. Am. Meteorol. Soc.},
number = {3},
pages = {437--471},
title = {{The \{NCEP/NCAR\} 40-Year Reanalysis Project}},
volume = {77},
year = {1996}
[5] M. Kanamitsu, W. Ebisuzaki, J. Woollen, S. Yang, J. J. Hnilo, M. Fiorino, and G. L. Potter, “\NCEP-DOE AMIP-II\ REANALYSIS \(R-2)\,” Bull. am. meteorol. soc., vol. Nov 2002, pp. 1631-1643, 2002.
author = {Kanamitsu, Masao and Ebisuzaki, Wesley and Woollen, Jack and Yang, Shi-Keng and Hnilo, J J and Fiorino, M and Potter, G L},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop/Kanamitsu et al. - 2002.pdf:pdf},
journal = {Bull. Am. Meteorol. Soc.},
pages = {1631--1643},
title = {{\{NCEP-DOE AMIP-II\} REANALYSIS \{(R-2)\}}},
volume = {Nov 2002},
year = {2002}
[6] [doi] S. Saha, S. Moorthi, H. Pan, X. Wu, J. Wang, S. Nadiga, P. Tripp, R. Kistler, J. Woollen, D. Behringer, H. Liu, D. Stokes, R. Grumbine, G. Gayno, J. Wang, Y. Hou, H. Chuang, H. H. Juang, J. Sela, M. Iredell, R. Treadon, D. Kleist, P. {Van Delst}, D. Keyser, J. Derber, M. Ek, J. Meng, H. Wei, R. Yang, S. Lord, H. {Van Den Dool}, A. Kumar, W. Wang, C. Long, M. Chelliah, Y. Xue, B. Huang, J. Schemm, W. Ebisuzaki, R. Lin, P. Xie, M. Chen, S. Zhou, W. Higgins, C. Zou, Q. Liu, Y. Chen, Y. Han, L. Cucurull, R. W. Reynolds, G. Rutledge, and M. Goldberg, “The NCEP Climate Forecast System Reanalysis,” Bull. am. meteorol. soc., vol. 91, iss. 8, pp. 1015-1057, 2010.
author = {Saha, Suranjana and Moorthi, Shrinivas and Pan, Hua-Lu and Wu, Xingren and Wang, Jiande and Nadiga, Sudhir and Tripp, Patrick and Kistler, Robert and Woollen, John and Behringer, David and Liu, Haixia and Stokes, Diane and Grumbine, Robert and Gayno, George and Wang, Jun and Hou, Yu-Tai and Chuang, Hui-Ya and Juang, Hann-Ming H. and Sela, Joe and Iredell, Mark and Treadon, Russ and Kleist, Daryl and {Van Delst}, Paul and Keyser, Dennis and Derber, John and Ek, Michael and Meng, Jesse and Wei, Helin and Yang, Rongqian and Lord, Stephen and {Van Den Dool}, Huug and Kumar, Arun and Wang, Wanqiu and Long, Craig and Chelliah, Muthuvel and Xue, Yan and Huang, Boyin and Schemm, Jae-Kyung and Ebisuzaki, Wesley and Lin, Roger and Xie, Pingping and Chen, Mingyue and Zhou, Shuntai and Higgins, Wayne and Zou, Cheng-Zhi and Liu, Quanhua and Chen, Yong and Han, Yong and Cucurull, Lidia and Reynolds, Richard W. and Rutledge, Glenn and Goldberg, Mitch},
doi = {10.1175/2010BAMS3001.1},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop/Saha et al. - 2010.pdf:pdf},
issn = {0003-0007},
journal = {Bull. Am. Meteorol. Soc.},
month = aug,
number = {8},
pages = {1015--1057},
title = {{The NCEP Climate Forecast System Reanalysis}},
url = {},
volume = {91},
year = {2010}
[7] K. Onogi, J. Tsutsui, H. Koide, M. Sakamoto, S. Kobayashi, H. Hatsushika, T. Matsumoto, N. Yamazaki, H. Kamahori, K. Takahashi, S. Kadokura, K. Wada, K. Kato, R. Oyama, T. Ose, N. Mannoji, and R. Taira, “The \JRA-25\ Reanalysis,” J. meteor. soc. japan, vol. 85, pp. 369-432, 2007.
author = {Onogi, Kazutoshi and Tsutsui, Junichi and Koide, Hiroshi and Sakamoto, Masami and Kobayashi, Shinya and Hatsushika, Hiroaki and Matsumoto, Takanori and Yamazaki, Nobuo and Kamahori, Hirotaka and Takahashi, Kiyotoshi and Kadokura, Shinji and Wada, Koji and Kato, Koji and Oyama, Ryo and Ose, Tomoaki and Mannoji, Nobutaka and Taira, Ryusuke},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop//Onogi et al. - 2007.pdf:pdf},
journal = {J. Meteor. Soc. Japan},
pages = {369--432},
title = {{The \{JRA-25\} Reanalysis}},
volume = {85},
year = {2007}
[8] [doi] A. Ebita, S. Kobayashi, Y. Ota, M. Moriya, R. Kumabe, K. Onogi, Y. Harada, S. Yasui, K. Miyaoka, K. Takahashi, H. Kamahori, C. Kobayashi, H. Endo, M. Soma, Y. Oikawa, and T. Ishimizu, “The Japanese 55-year Reanalysis “JRA-55”: An Interim Report,” Sola, vol. 7, pp. 149-152, 2011.
author = {Ebita, Ayataka and Kobayashi, Shinya and Ota, Yukinari and Moriya, Masami and Kumabe, Ryoji and Onogi, Kazutoshi and Harada, Yayoi and Yasui, Soichiro and Miyaoka, Kengo and Takahashi, Kiyotoshi and Kamahori, Hirotaka and Kobayashi, Chiaki and Endo, Hirokazu and Soma, Motomu and Oikawa, Yoshinori and Ishimizu, Takahisa},
doi = {10.2151/sola.2011-038},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop/Ebita et al. - 2011.pdf:pdf},
issn = {1349-6476},
journal = {Sola},
pages = {149--152},
title = {{The Japanese 55-year Reanalysis “JRA-55”: An Interim Report}},
url = {},
volume = {7},
year = {2011}
[9] [doi] G. P. Compo, J. S. Whitaker, P. D. Sardeshmukh, N. Matsui, R. J. Allan, X. Yin, J. {E. Gleason}, R. S. Vose, G. Rutledge, P. Bessemoulin, S̈. Brönnimann, M. Brunet, R. I. Crouthamel, A. N. Grant, P. Y. Groisman, P. D. Jones, M. C. Kruk, A. C. Kruger, G. J. Marshall, M. Maugeri, H. Y. Mok, N. \O. {andT. F. Ross}, R. M. Trigo, X. L. Wang, S. D. Woodruff, and S. J. Worleyu, “The Twentieth Century Reanalysis Project,” Q. j. r. meteorol. soc., vol. 137, pp. 1-28, 2011.
author = {Compo, G P and Whitaker, J S and Sardeshmukh, P D and Matsui, N and Allan, R J and Yin, X and {E. Gleason}, Jr. and Vose, R S and Rutledge, G and Bessemoulin, P and Br\"{o}nnimann, S̈. and Brunet, M and Crouthamel, R I and Grant, A N and Groisman, P Y and Jones, P D and Kruk, M C and Kruger, A C and Marshall, G J and Maugeri, M and Mok, H Y and {andT. F. Ross}, \O Nordli and Trigo, R M and Wang, X L and Woodruff, S D and Worleyu, S J},
doi = {10.1002/qj.776},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop/Compo et al. - 2011.pdf:pdf},
journal = {Q. J. R. Meteorol. Soc.},
pages = {1--28},
title = {{The Twentieth Century Reanalysis Project}},
volume = {137},
year = {2011}

A new “wave” of interest for the polar vortex and Stratospheric Sudden Warming events

The recent cold weather in America (referred as the 2014 North American cold wave by some) has generated significant interest for the polar vortex in popular science articles. A large number of them attribute the cold weather to the polar vortex which undergoes what we may call a Stratospheric Sudden Warming (SSW) event [1], when the winds in the upper part of the atmosphere decelerate suddenly. Many of those online articles provide only obscure explanation of how the vortex breakdown may produce cold temperatures over America. The impact of stratospheric circulation on surface weather is after all still uncertain and is the topic of ongoing scientific research [2, 3].

According to our recent observations of stratospheric polar vortex, it is still too early to speak of a Stratospheric Sudden Warming event. Although the strength of the vortex decreased suddenly in the beginning of January, its overall strength did not reach the traditional magnitude used to define SSW events (a reversal of zonal wind at 60N and 10 hPa or a NAM index approximately below -3 for a “weak vortex event” [4]). There is no doubt however that the vortex has decelerated suddenly. Events of strong and rapid deceleration of the stratospheric vortex (Stratospheric Vortex Weakening (SVW) events) are also known to be accompanied by anomalous tropospheric circulation [5]

[1] A. J. Charlton and L. M. Polvani, “A New Look at Stratospheric Sudden Warmings. Part I: Climatology and Modeling Benchmarks,” J. climate, vol. 20, pp. 449-469, 2007.
author = {Charlton, Andrew J and Polvani, Lorenzo M},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop//Charlton, Polvani - 2007.pdf:pdf},
journal = {J. Climate},
pages = {449--469},
title = {{A New Look at Stratospheric Sudden Warmings. Part I: Climatology and Modeling Benchmarks}},
volume = {20},
year = {2007}
[2] [doi] D. M. Mitchell, L. J. Gray, J. Anstey, M. P. Baldwin, and A. J. Charlton-Perez, “The Influence of Stratospheric Vortex Displacements and Splits on Surface Climate,” J. climate, vol. 26, iss. 8, pp. 2668-2682, 2013.
author = {Mitchell, Daniel M. and Gray, Lesley J. and Anstey, James and Baldwin, Mark P. and Charlton-Perez, Andrew J.},
doi = {10.1175/JCLI-D-12-00030.1},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop//Mitchell et al. - 2013.pdf:pdf},
issn = {0894-8755},
journal = {J. Climate},
month = apr,
number = {8},
pages = {2668--2682},
title = {{The Influence of Stratospheric Vortex Displacements and Splits on Surface Climate}},
url = {},
volume = {26},
year = {2013}
[3] [doi] D. I. V. Domeisen, L. Sun, and G. Chen, “The role of synoptic eddies in the tropospheric response to stratospheric variability,” Geophys. res. lett., vol. 40, pp. 1-5, 2013.
author = {Domeisen, Daniela I.V. and Sun, Lantao and Chen, Gang},
doi = {10.1002/grl.50943},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop//Domeisen, Sun, Chen - 2013.pdf:pdf},
issn = {00948276},
journal = {Geophys. Res. Lett.},
month = sep,
pages = {1--5},
title = {{The role of synoptic eddies in the tropospheric response to stratospheric variability}},
url = {},
volume = {40},
year = {2013}
[4] [doi] M. P. Baldwin and T. J. Dunkerton, “Stratospheric Harbingers of Anomalous Weather Regimes,” Science, vol. 294, pp. 581-584, 2001.
author = {Baldwin, Mark P and Dunkerton, Timothy J},
doi = {10.1126/science.1063315},
file = {:C$\backslash$:/Users/Patrick/Documents/Mendeley Desktop//Baldwin, Dunkerton - 2001.pdf:pdf},
journal = {Science},
pages = {581--584},
title = {{Stratospheric Harbingers of Anomalous Weather Regimes}},
volume = {294},
year = {2001}
[5] [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.
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 = {},
year = {2013}

The Northern Annular Mode (NAM) index at 10 hPa only shows positive values in the beginning of January.


Overall, NAM values went from positive to neutral in the stratosphere and from negative to neutral in the troposphere. Still too early to speak of downward influence.


Although it is still too early to refer to the evolution of the stratospheric vortex in early 2014 as Stratospheric Sudden Warming event, it will be interesting to follow the evolution of the stratospheric vortex in the following weeks. Also see the polar vortex animation of past SSW/SVW events!

Attending the WCRP Regional Workshop on Stratosphere-Troposphere Processes and their Role in Climate

Poster P-22 : The role of momentum forcing by planetary-scale waves in the onset of tropospheric circulation anomalies during stratospheric sudden warming events

Official website