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A New Real-time Lagrangian Diagnostic System for Stratosphere-troposphere Exchange: Evaluation During a Balloon Sonde Campaign in Eastern Canada : Volume 11, Issue 10 (18/10/2011)

By Bourqui, M. S.

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Book Id: WPLBN0003995680
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File Size: Pages 45
Reproduction Date: 2015

Title: A New Real-time Lagrangian Diagnostic System for Stratosphere-troposphere Exchange: Evaluation During a Balloon Sonde Campaign in Eastern Canada : Volume 11, Issue 10 (18/10/2011)  
Author: Bourqui, M. S.
Volume: Vol. 11, Issue 10
Language: English
Subject: Science, Atmospheric, Chemistry
Collections: Periodicals: Journal and Magazine Collection (Contemporary), Copernicus GmbH
Historic
Publication Date:
2011
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

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Hocking, W., Beaudoin, L., Bourqui, M. S., Osman, M., Davies, J., Tarasick, D.,...Wilkinson, R. (2011). A New Real-time Lagrangian Diagnostic System for Stratosphere-troposphere Exchange: Evaluation During a Balloon Sonde Campaign in Eastern Canada : Volume 11, Issue 10 (18/10/2011). Retrieved from http://ebooklibrary.org/


Description
Description: Department of Atmospheric and Oceanic Sciences, Department of Chemistry, McGill University, Montréal, Québec, Canada. A new real-time Lagrangian diagnostic system for stratosphere-troposphere exchange (STE) developed for Environment Canada (EC) has been delivering daily archived data since 20 July 2010. The STE calculations are performed globally following the Lagrangian approach proposed in Bourqui (2006) using medium-range, high-resolution operational global weather forecasts. Following every weather forecast, trajectories are started from a dense three-dimensional grid covering the globe, and are calculated for six days of the forecast. All trajectories crossing either the dynamical tropopause (±2 PVU) or the 380 K isentrope and having a residence time greater than 12 h are archived, and also used to calculate several diagnostics. This system provides daily global STE forecasts that can be used to guide field campaigns, among other applications. The archived data set offers unique high-resolution information on transport across the tropopause for both extra-tropical hemispheres and the tropics. This will be useful for improving our understanding of STE globally, and as a reference for the evaluation of lower-resolution models. This new data set is evaluated here against measurements taken during a balloon sonde campaign with daily launches from three stations in eastern Canada (Montreal, Egbert, and Walsingham) for the period from 12 July to 4 August 2010. The campaign found an unexpectedly high number of observed stratospheric intrusions: 79% (38%) of the profiles appear to show the presence of stratospheric air below 500 hPa (700 hPa). An objective identification algorithm developed for this study is used to identify layers in the balloon-sonde profiles affected by stratospheric air and to evaluate the Lagrangian STE forecasts. We find that the predictive skill for the overall intrusion depth is excellent for intrusions penetrating down to 300 and 500 hPa, while it becomes negligible for intrusions penetrating below 700 hPa. Nevertheless, the statistical representation of these deep intrusions is reasonable, with an average bias of 24%. Evaluation of the skill at representing the detailed structures of the stratospheric intrusions shows good predictive skill down to 500 hPa, reduced predictive skill between 500 and 700 hPa, and none below. A significant low statistical bias of about 30% is found in the layer between 500 to 700 hPa. However, analysis of missed events at one site, Montreal, shows that 70% of them coincide with candidate clusters of trajectories that pass through Montreal, but that are too dispersed to be detected in the close neighbourhood of the station. This allows us to expect a negligible bias throughout the troposphere in the spatially averaged STE frequency derived from this data set, for example in climatological maps of STE mass fluxes.

Summary
A new real-time Lagrangian diagnostic system for stratosphere-troposphere exchange: evaluation during a balloon sonde campaign in eastern Canada

Excerpt
Appenzeller, C., Holton, J. R., and Rosenlof, K. H.: Seasonal variation of mass transport across the tropopause, J. Geophys. Res., 101, 15071–15078, 1996.; Bourqui, M. S.: Stratosphere-troposphere exchange from the Lagrangian perspective: a case study and method sensitivities, Atmos. Chem. Phys., 6, 2651–2670, doi:10.5194/acp-6-2651-2006, 2006.; Bourqui, M. S. and Trépanier, P.-Y.: Descent of deep stratospheric intrusions during the IONS August 2006 campaign, J. Geophys. Res., 115, D18301, doi:10.1029/2009JD013183, 2010.; Cooper, O., Stohl, A., Hubler, G., Hsie, E., Parrish, D., Tuck, A., Kiladis, G., Oltmans, S., Johnson, B., Shapiro, M., Moody, J., and Lefohn, A.: Direct transport of midlatitude stratospheric ozone into the lower troposphere and marine boundary layer of the tropical Pacific Ocean, J. Geophys. Res., 110, D23310, doi:10.1029/2005JD005783, 2005.; Côté, J., Desmarais, J., Gravel, S., Methot, A., Patoine, A., Roch, M., and Staniforth, A.: The operational CMC-MRB Global Environmental Multiscale (GEM) model. Part II: Results, Mon. Wea. Rev., 126, 1397–1418, 1998{a}.; Côté, J., Gravel, S., Méthot, A., Patoine, A., Roch, M., and Staniforth, A.: The Operational CMCMRB Global Environmental Multiscale (GEM) Model. Part I: Design considerations and formulation, Mon. Wea. Rev., 126, 1373–1395, 1998{b}.; Shapiro, M. A.: Further evidence of the mesoscale and turbulent structure of upper level jet stream – frontal zone systems, Mon. Wea. Rev., 106, 1100–1111, 1978.; Gerasopoulos, E., Zanis, P., Papastefanou, C., Zerefos, C. S., Ioannidou, A., and Wernli, H.: A complex case study of down to the surface intrusions of persistent stratospheric air over the Eastern Mediterranean, Atmos. Environ., 40, 4113–4125, doi:10.1016/j.atmosenv.2006.03.022, 2006.; Gettelman, A. and Sobel, A. H.: Direct diagnoses of Stratosphere-Troposphere Exchange, J. Atmos. Sci., 57, 3–16, 2000.; Gray, S. L.: A case study of stratosphere to troposphere transport: The role of convective transport and the sensitivity to model resolution, J. Geophys.\ Res., 108, 4590, doi:10.1029/2002JD003,317, 2003.; Hall, T. M. and Holzer, M.: Advective-diffusive mass flux and implications for stratosphere-troposphere exchange, Geophys. Res. Lett., 30, 1222, doi:10.1029/2002GL016,419, 2003.; Hegglin, M. I. and Shepherd, T. G.: Large climate-induced changes in ultraviolet index and stratosphere-to-troposphere ozone flux, Nat. Geosci., 2, 687–691, 2009.; Hoerling, P. M., Schaack, T. K., and Lenzen, A. J.: A global analysis of stratospheric-tropospheric exchange during northern winter, Mon. Wea. Rev., 121, 162–172, 1993.; Holton, J. R., Haynes, P. H., McIntyre, M. E., Douglass, A. R., Rood, R. B., and Pfister, L.: Stratosphere-Troposphere Exchange, Rev. Geophys., 33, 403–439, 1995.; Jolliffe, I. T. and Stephenson, D. B.: in: Forecast Verification: A Practitioner's Guide, Atmospheric Science, Wiley and Sons, Chichester, 2003.; Komhyr, W. D.: Electrochemical concentration cells for gas analysis, Ann.\ Geophysicae, 25, 203–210, 1969.; Langford, A. O., Masters, C. D., Proffitt, M. H., Hsie, E.-Y., and Tuck, A. E.: Ozone measurements in a tropopause fold associated with a cut-off low system, Geophys. Res. Letters, 23, 2501–2504, 1996.; Lefohn, A. S., Wernli, H., Shadwick, D., Limbach, S., Oltmans, S. J., and Shapiro, M.: The importance of stratospheric-tropospheri

 

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