A Three-Dimensional View of the Evolution of Midlatitude Stratospheric Intrusions

M. Bithell Rutherford Appleton Laboratory, Chilton Didcot, Oxfordshire, United Kingdom

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L. J. Gray Rutherford Appleton Laboratory, Chilton Didcot, Oxfordshire, United Kingdom

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B. D. Cox Rutherford Appleton Laboratory, Chilton Didcot, Oxfordshire, United Kingdom

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Abstract

Three-dimensional views of midlatitude stratospheric intrusions are presented. The views are obtained by plotting a surface of constant potential vorticity (PV), where the PV is diagnosed from a 6-day run of the U.K. Universities Global Atmospheric Modelling Project General Circulation Model. The PV = 1 × 10−6 K kg−1 m2 s−1 (=1 PVU) isosurface is chosen as representative of the tropopause. The evolution of this surface is examined during the development of baroclinic waves in the Northern Hemisphere during October 1990. The developments show a number of features expected during the evolution of upper-level troughs, such as vortex roll-up, and the generation of tropopause folds, in which air from the stratosphere intrudes downward into the troposphere. However, it is shown that the combined effects of deformation and convergence lead to the rapid collapse of folded features to leave low-level tubes of PV, together with higher-level filaments. The result is that the air intruded in the vicinity of the upper-level fold or filament is rapidly removed to other regions (cutoff lows/highs, low-level tubes, or the stratosphere). It is also shown that high pressure regions can possess similar folded structures, which also rapidly collapse to the model grid scale. These effects are examined in more detail using a contour advection technique. There is evidence for the existence of the low-level tubes both in assimilated datasets and in other models. If they are real structures, they should be observable as temperature and humidity anomalies in the same way as folds, but ground-based observations are unlikely to be able to separate the two kinds of structure—aircraft flights would be required.

Corresponding author address: Dr. M. Bithell, Rutherford Appleton Laboratory, Chilton Didcot, Oxfordshire, OXII OQX United Kingdom.

Email: bithell@rl.ac.uk

Abstract

Three-dimensional views of midlatitude stratospheric intrusions are presented. The views are obtained by plotting a surface of constant potential vorticity (PV), where the PV is diagnosed from a 6-day run of the U.K. Universities Global Atmospheric Modelling Project General Circulation Model. The PV = 1 × 10−6 K kg−1 m2 s−1 (=1 PVU) isosurface is chosen as representative of the tropopause. The evolution of this surface is examined during the development of baroclinic waves in the Northern Hemisphere during October 1990. The developments show a number of features expected during the evolution of upper-level troughs, such as vortex roll-up, and the generation of tropopause folds, in which air from the stratosphere intrudes downward into the troposphere. However, it is shown that the combined effects of deformation and convergence lead to the rapid collapse of folded features to leave low-level tubes of PV, together with higher-level filaments. The result is that the air intruded in the vicinity of the upper-level fold or filament is rapidly removed to other regions (cutoff lows/highs, low-level tubes, or the stratosphere). It is also shown that high pressure regions can possess similar folded structures, which also rapidly collapse to the model grid scale. These effects are examined in more detail using a contour advection technique. There is evidence for the existence of the low-level tubes both in assimilated datasets and in other models. If they are real structures, they should be observable as temperature and humidity anomalies in the same way as folds, but ground-based observations are unlikely to be able to separate the two kinds of structure—aircraft flights would be required.

Corresponding author address: Dr. M. Bithell, Rutherford Appleton Laboratory, Chilton Didcot, Oxfordshire, OXII OQX United Kingdom.

Email: bithell@rl.ac.uk

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  • Ancellet G., J. Pelon, M. Beekman, A. Papayannis, and G. Megie, 1991: Ground-based lidar studies of ozone exchanges between the stratosphere and the troposphere. J. Geophys. Res.,96, 22 401–22 421.

  • ——, M. Beekman, and A. Papayannis, 1994: Impact of a cut-off low development on downward transport of ozone in the troposphere. J. Geophys. Res.,99, 3451–3468.

  • Appenzeller, C., and H. C. Davies, 1992: Structure of stratospheric intrusions into the troposphere. Nature,358, 570–572.

  • ——, and W. A. Norton, 1996: Fragmentation of stratospheric intrusions. J. Geophys. Res.,101, 1435–1456.

  • Bamber, D. J., P. G. Healey, B. M. Jones, S. A. Penkett, A. F. Tuck, and G. Vaughan, 1984: Vertical profiles of tropospheric gases—Chemical consequences of stratospheric intrusions. Atmos. Environ.,18, 1759–1766.

  • Betts, A. K., 1986: A new convective adjustment scheme. Part I: Observational and theoretical basis. Quart. J. Roy. Meteor. Soc.,112, 677–691.

  • ——, and M. J. Miller, 1986: A new convective adjustment scheme II: Single column tests using GATE wave, BOMEX, ATEX, and arctic air-mass data sets. Quart. J. Roy. Meteor. Soc.,112, 693–710.

  • Browell, E. V., E. F. Danielsen, S. Ismail, G. L. Gregory, and S. M. Bleck, 1987: Tropopause fold structure determined from airborne lidar and in situ measurements. J. Geophys. Res.,92, 2112–2120.

  • Bush, A. B. G., and W. R. Peltier, 1994: Tropopause folds and synoptic-scale baroclinic wave life cycles. J. Atmos. Sci.,51, 1581–1604.

  • Cox, B. D., M. Bithell, and L. J. Gray, 1995: A general circulation model study of a tropopause folding event at middle latitudes. Quart. J. Roy. Meteor. Soc.,121, 883–910.

  • ——, ——, and ——, 1997: Modelling of stratospheric intrusions within a mid-latitude synoptic-scale disturbance. Quart. J. Roy. Meteor. Soc.,123, 1377–1403.

  • Danielsen, E. F., R. S. Hipskind, W. L. Starr, J. F. Vedder, S. E. Gaines, D. Kley, and K. K. Kelly, 1991: Irreversible transport in the stratosphere by internal waves of short vertical wavelength. J. Geophys. Res.,96, 17 433–17 452.

  • Dritschel, D. G., 1989: Contour dynamics and contour surgery: Numerical algorithms for extended high resolution modelling of vortex dynamics in two-dimensional inviscid incompressible flows. Comput. Phys. Rep.,10, 78–146.

  • Ebel, A., H Hass, H. J. H. Jakobs, M. Laube, M. Memmesheimer, A. Oberreuter, H. Geiss, and Y.-H. Kuo, 1990: Simulation of ozone intrusion caused by a tropopause fold and cut-off low. Atmos. Environ.,25A, 2131–2144.

  • Gray, L. J., M. Bithell, and B. D. Cox, 1994: The role of specific humidity fields in the diagnosis of stratosphere troposphere exchange. Geophys. Res. Lett.,21, 2103–2106.

  • Hoerling, M. P., T. K. Schaak, and A. J. Lenzen, 1993: A global analysis of stratospheric–tropospheric exchange during northern winter. Mon. Wea. Rev.,121, 162–172.

  • Hoskins, B. J., M. E. McIntyre, and A. W. Robertson, 1985: On the use and significance of isentropic potential vorticity maps. Quart. J. Roy. Meteor. Soc.,111, 877–946.

  • Kritz, M. A., S. W. Rosner, E. F. Danielsen, and H. B. Selkirk, 1991:Air mass origins and troposphere–stratosphere exchange associated with mid-latitude cyclogenesis and tropopause folding inferred from SUPER 7Be measurements. J. Geophys. Res.,96, 17 504–17 414.

  • Lamarque, J.-F., and P. G. Hess, 1994: Cross-tropopause mass exchange and potential vorticity budget in a simulated tropopause folding. J. Atmos Sci.,51, 2246–2269.

  • Li, D., 1992: The damping of two-grid waves in the lower stratosphere in the UGAMP GCM by modification of the radiation scheme. UGAMP Tech. Rep. 23, Dept. of Meteorology, University of Reading, United Kingdom.

  • Morcrette, J.-J., 1990: Impact of changes to the radiation transfer parametrizations plus cloud optical properties in the ECMWF model. Mon. Wea. Rev.,118, 847–873.

  • Norton, W. A., 1994: Breaking Rossby waves in a model stratosphere diagnosed by a vortex-following co-ordinate system and a contour advection technique. J. Atmos. Sci.,51, 654–673.

  • Palmer, T. N., G. J. Shutts, and R. Swinbank, 1986: Alleviation of a systematic westerly bias in general circulation and numerical weather predication models through an orographic gravity wave drag parametrization. Quart. J. Roy. Meteor. Soc.,112, 1001–1039.

  • Slingo, J. M., 1987: The development and verification of a cloud predication scheme for the ECMWF model. Quart. J. Roy. Meteor. Soc.,113, 899–927.

  • Spaete, P., D. R. Johnson, and T. K. Schaak, 1994: Stratospheric–tropospheric mass exchange during the President’s Day storm. Mon. Wea. Rev.,122, 424–439.

  • Thorncroft, C. D., B. J. Hoskins, and M. E. McIntyre, 1993: Two paradigms of baroclinic-wave life cycle behaviour. Quart. J. Roy. Meteor. Soc.,119, 17–55.

  • Tiedtke, M., W. A. Heckley, and J. M. Slingo, 1988: Tropical forecasting at ECMWF: The influence of physical parameterization on the mean structure of forecasts and analyses. Quart. J. Roy. Meteor. Soc.,114, 649–664.

  • Vaughan, G., and J. D. Price, 1991: On the relation between total ozone and meteorology. Quart. J. Roy. Meteor. Soc.,117, 1281–1298.

  • ——, ——, and A. Howells, 1994: Transport into the troposphere in a tropopause fold. Quart. J. Roy. Meteor. Soc.,120, 1085–1103.

  • Viezee, W., W. B. Johnson, and H. B. Singh, 1983: Stratosphere ozone in the lower troposphere. Part II: Assessment of downward flux and ground-level impact. Atmos. Environ.,17, 1979–1993.

  • Wirth, V., 1995: Diabatic heating in an axisymmetric cut-off cyclone and related stratosphere–troposphere exchange. Quart. J. Roy. Meteor. Soc.,121, 127–147.

  • World Meteorological Organization, 1985: Atmospheric ozone 1985, Vol. 1. Rep. 16, WMO, Geneva, 392 pp.

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