Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Review Article
  • Published:

Physical processes in the tropical tropopause layer and their roles in a changing climate

Nature Geoscience volume 6, pages 169–176 (2013)Cite this article

Subjects

Abstract

Tropical climate and the composition of the global upper atmosphere are affected by the tropical tropopause layer — the atmospheric transition zone between the well-mixed, convective troposphere (up to altitudes of 12–14 km) and the highly stratified stratosphere (above about 18 km). Featuring chemical and dynamical properties that are midway between those of the troposphere and stratosphere, the tropopause layer is maintained by a complex interplay between large- and small-scale circulation patterns, deep convection, clouds and radiation. Tropospheric air enters the stratosphere primarily in the tropics. Ozone- and aerosol-related constituents of the global stratosphere, as well as water vapour content, are therefore largely determined by the composition of the air near the tropical tropopause. Over the past years, it has emerged that both slow ascent and rapid deep convection contribute to the composition and thermal structure of the tropical tropopause layer. Ice formation processes at low temperatures affect the efficacy of freeze drying as air passes through the cold tropopause region. Transport and mixing in the tropopause region has been found to be closely linked with the Asian monsoon and other tropical circulation systems. Given these connections, climate change is expected to influence the tropopause layer, for example through enhanced large-scale upwelling of air and potential changes in tropical convection, air temperature, chemical composition and cirrus.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Schematic of the large-scale structure and circulation of the TTL in the latitude–height plane.
Figure 2: Satellite observations of water vapour in the lower stratosphere demonstrate the transport of air from the TTL to high latitudes.
Figure 3: Large differences exist in current estimates of radiative heating rates in the TTL, and these result in substantial differences in upward transport calculations.
Figure 4: The horizontal structure of ozone in the lower stratosphere during boreal summer shows the influence of monsoonal circulations on the TTL.
Figure 5: Interannual changes in global stratospheric water vapour are closely linked to tropical tropopause temperatures.
Figure B1: Seasonal cycle of cold-point tropical tropopause temperature.

Similar content being viewed by others

References

  1. Folkins, I. & Martin, R. V. The vertical structure of tropical convection and its impact on the budgets of water vapor and ozone. J. Atmos. Sci. 62, 1560–1573 (2005).

    Google Scholar 

  2. Danielsen, E. F. In situ evidence of rapid, vertical, irreversible transport of lower tropospheric air into the lower tropical stratosphere by convective cloud turrets and by larger-scale upwelling in tropical cyclones. J. Geophys. Res. 98, 8665–8681 (1993).

    Google Scholar 

  3. Zipser, E. J., Cecil, D. J., Liu, C., Nesbitt, S. W. & Yorty, D. P. Where are the most intense thunderstorms on earth? Bull. Am. Meteor. Soc. 87, 1057–1071 (2006).

    Google Scholar 

  4. De Reus, M. et al. Evidence for ice particles in the tropical stratosphere from in situ measurements. Atmos. Phys. Chem. 9, 6775–6792 (2009).

    Google Scholar 

  5. Gettelman, A. & Forster, P. M. de F. A climatology of the tropical tropopause layer. J. Met. Soc. Japan 80, 911–924 (2002).

    Google Scholar 

  6. Fu, Q., Hu, Y. X. & Yang, Q. Identifying the top of the tropical tropopause layer from vertical mass flux analysis and CALIPSO lidar cloud observations. Geophys. Res. Lett. 34, L14813 (2007).

    Google Scholar 

  7. Fueglistaler, S. et al. Tropical tropopause layer. Rev. Geophys. 47, 1–31 (2009).

    Google Scholar 

  8. Brewer, A. M. Evidence for a world circulation provided by the measurements of helium and water vapor distribution in the stratosphere. Q. J. R. Meteorol. Soc. 75, 351–363 (1949).

    Google Scholar 

  9. Mote, P. W. et al. An atmospheric tape recorder: The imprinting of tropical tropopause temperatures on stratospheric water vapor. J. Geophys. Res. 101, 3989–4006 (1996).

    Google Scholar 

  10. Rosenlof, K. H., Tuck, A. F., Kelly, K. K., Russell, J. M. & McCormick, M. P. Hemispheric asymmetries in water vapor and inferences about transport in the lower stratosphere. J. Geophys. Res. 102, 13213–13234 (1997).

    Google Scholar 

  11. Randel, W. J., Seidel, D. J. & Pan, L. L. Observational characteristics of double tropopauses. J. Geophys. Res. 112, D07309 (2007).

    Google Scholar 

  12. Pan, L. L. et al. Tropospheric intrusions associated with the secondary tropopause. J. Geophys. Res. 114, D10302 (2009).

    Google Scholar 

  13. Marcy, T. P. et al. Measurements of trace gases in the tropical tropopause layer. Atmos. Environ. 41, 7253–7261 (2007).

    Google Scholar 

  14. Santee, M. L. et al. Trace gas evolution in the lowermost stratosphere from Aura Microwave Limb Sounder measurements. J. Geophys. Res. 116, D18306 (2011).

    Google Scholar 

  15. Konopka, P., Grooss, J.-U., Plöger, F. & Müller, R. Annual cycle of horizontal in-mixing into the lower tropical stratosphere. J. Geophys. Res. 114, D19111 (2009).

    Google Scholar 

  16. Wang, P-H., Minnis, P., McCormick, M. P., Kent, G. S. & Skeens, K. M. A 6-year climatology of cloud occurrence frequency from Stratospheric Aerosol Gas Experiment II observations (1985–1990). J. Geophys. Res. 101, 29407–29429 (1996).

    Google Scholar 

  17. Sassen, K., Wang, Z. & Liu, D. Cirrus clouds and deep convection in the tropics: Insights from CALIPSO and CloudSat. J. Geophys. Res. 114, D00H06 (2009).

    Google Scholar 

  18. Stephens, G. L. Cloud feedbacks in the climate system: A critical review. J. Clim. 18, 237–273 (2005).

    Google Scholar 

  19. Winker, D. M., Hunt, W. H. & McGill, M. J. Initial performance assessment of CALIPSO. Geophys. Res. Lett. 34, L19803 (2007).

    Google Scholar 

  20. Pan, L. L. & Munchak, L. A. Relationship of cloud top to the tropopause and jet structure from CALIPSO data. J. Geophys. Res. 116, D12201 (2011).

    Google Scholar 

  21. Virts, K. S., Wallace, J. M., Fu, Q. & Ackerman, T. P. Tropical tropopause transition layer cirrus as represented by CALIPSO lidar observations. J. Atmos. Sci. 67, 3113–3129 (2010).

    Google Scholar 

  22. Virts, K. S. & Wallace, J. M. Annual, interannual and intraseasonal variability of tropical tropopause transition layer cirrus. J. Atmos. Sci. 67, 3097–3112 (2010).

    Google Scholar 

  23. Soden, B. J. et al. Quantifying climate feedbacks using radiative kernels. J. Clim. 21, 3504–3520 (2008).

    Google Scholar 

  24. Hartmann, D. L. & Larson, K. An important constraint on tropical cloud-climate feedback. Geophys. Res. Lett. 29, 1951 (2002).

    Google Scholar 

  25. Harrop, B. E. & Hartmann, D. L. Testing the role of radiation in determining tropical cloud top temperature. J. Clim. 25, 5731–5747 (2012).

    Google Scholar 

  26. Haynes, P. H., Marks, C. J., McIntyre, M. E., Shepherd, T. G. & Shine, K. P. On the “downward control” of extratropical diabatic circulations by eddy-induced mean zonal forces. J. Atmos. Sci. 48, 651–678 (1991).

    Google Scholar 

  27. Plumb, R. A. & Eluszkiewicz, J. The Brewer-Dobson circulation: dynamics of the tropical upwelling. J. Atmos. Sci. 56, 868–890 (1999).

    Google Scholar 

  28. Randel, W. J., Garcia, R. & Wu, F. Dynamical balances and tropical stratospheric upwelling. J. Atmos. Sci. 65, 3584–3595 (2008).

    Google Scholar 

  29. Calvo, N., Garcia, R. R., Randel, W. J. & Marsh, D. Dynamical mechanism for the increase in tropical upwelling in the lowermost tropical stratosphere during warm ENSO events. J. Atmos. Sci. 67, 2331–2340 (2010).

    Google Scholar 

  30. Garcia, R. R. & Randel, W. J. Acceleration of the Brewer-Dobson circulation due to increases in greenhouse gases. J. Atmos. Sci. 65, 2731–2739 (2008).

    Google Scholar 

  31. Shepherd, T. G. & McLandress, C. A robust mechanism for strengthening of the Brewer-Dobson circulation in response to climate change: critical-layer control of subtropical wave breaking. J. Atmos. Sci. 68, 784–797 (2011).

    Google Scholar 

  32. Yulaeva, E., Holton, J. R. & Wallace, J. M. On the cause of the annual cycle in the tropical lower stratospheric temperature. J. Atmos. Sci. 51, 169–174 (1994).

    Google Scholar 

  33. Holton, J. R. et al. Stratosphere–troposphere exchange. Rev. Geophys. 33, 403–439 (1995).

    Google Scholar 

  34. Taguchi, M. Wave driving in the tropical lower stratosphere as simulated by WACCM. Part I: annual cycle. J. Atmos. Sci. 66, 2029–2043 (2009).

    Google Scholar 

  35. Chen, G. & Sun, L. Mechanisms of the tropical upwelling branch of the Brewer-Dobson circulation: the role of extratropical waves. J. Atmos. Sci. 68, 2878–2892 (2011).

    Google Scholar 

  36. Garney, H., Dameris, M., Randel, W. J., Bodeker, G. E. & Deckert, R. Dynamically forced increase of tropical upwelling in the lower stratosphere. J. Atmos. Sci. 68, 1214–1233 (2011).

    Google Scholar 

  37. Boehm, M. T. & Lee, S. The implications of tropical Rossby waves for tropical tropopause cirrus formation and for the equatorial upwelling of the Brewer–Dobson circulation. J. Atmos. Sci. 60, 247–261 (2003).

    Google Scholar 

  38. Norton, W. A. Tropical wave driving of the annual cycle in tropical tropopause temperatures. Part II: Model results. J. Atmos. Sci. 63, 1420–1431 (2006).

    Google Scholar 

  39. Ryu, J.-H. & Lee, S. Effect of tropical waves on the tropical tropopause transition layer upwelling. J. Atmos. Sci. 67, 3130–3148 (2010).

    Google Scholar 

  40. Fueglistaler, S., Haynes, P. H. & and Forster, P. M. The annual cycle in lower stratospheric temperatures revisited. Atmos. Chem. Phys. 11, 3701–3711 (2011).

    Google Scholar 

  41. Polvani, L. M. & Solomon, S. The signature of ozone depletion on tropical temperature trends, as revealed by their seasonal cycle in model integrations with single forcings. J. Geophys. Res. 117, D17102 (2012).

    Google Scholar 

  42. Konopka, P. et al. Annual cycle of ozone at and above the tropical tropopause: observations versus simulations with the Chemical Lagrangian Model of the Stratosphere (CLaMS). Atmos. Chem. Phys. 10, 121–132 (2010).

    Google Scholar 

  43. Ploeger, F. et al. Horizontal transport affecting trace gas seasonality in the Tropical Tropopause Layer (TTL). J. Geophys. Res. 117, D09303 (2012).

    Google Scholar 

  44. Gettelman, A. & Birner, T. Insights into Tropical Tropopause Layer processes using global models. J. Geophys. Res. 112, D23104 (2007).

    Google Scholar 

  45. James, R., Bonazzola, M., Legras, B., Subled, K. & Fueglistaler, K. Water vapor transport and dehydration above convective outflow during Asian monsoon. Geophys. Res. Lett. 35, L20810 (2008).

    Google Scholar 

  46. Bergman, J. W., Jensen, E. J., Pfister, L. & Yang, Q. Seasonal differences of vertical-transport efficiency in the tropical tropopause layer: On the interplay between tropical deep convection, large-scale vertical ascent, and horizontal circulations. J. Geophys. Res. 117, D05302 (2012).

    Google Scholar 

  47. Adler, R. F. & Mack, R. A. Thunderstorm cloud top dynamics as inferred from satellite observations and a cloud parcel model. J. Atmos. Sci. 43, 1945–1960 (1986).

    Google Scholar 

  48. Yang, Q., Fu, Q. & Hu, Y. Radiative impacts of clouds in the tropical tropopause layer. J. Geophys. Res. 115, D00H12 (2010).

    Google Scholar 

  49. Levine, J. G., Braesicke, P., Harris, N. R. P., Savage, N. H. & Pyle, J. A. Pathways and timescales for troposphere-to-stratosphere transport via the tropical tropopause layer and their relevance for very short lived substances. J. Geophys. Res. 112, D04308 (2007).

    Google Scholar 

  50. Aschmann, J., Sinnhuber, B. M., Atlas, E. L. & Schauffler, S. M. Modeling the transport of very short-lived substances into the tropical upper troposphere and lower stratosphere. Atmos. Chem. Phys. 9, 9237–9247 (2009).

    Google Scholar 

  51. Jensen, E. J., Ackerman, A. S. & Smith, J. A. Can overshooting convection dehydrate the tropical tropopause layer? J. Geophys. Res. 112, D11209 (2007).

    Google Scholar 

  52. Sherwood, S. C. & Dessler, A. E., On the control of stratospheric humidity. Geophys. Res. Lett. 27, 2513–2516 (2000).

    Google Scholar 

  53. Corti, T. et al. Unprecedented evidence for deep convection hydrating the tropical stratosphere. Geophys. Res. Lett. 35, L10810 (2008).

    Google Scholar 

  54. Khaykin, S. et al. Hydration of the lower stratosphere by ice crystal geysers over land convective systems. Atmos. Chem. Phys. 9, 2275–2287 (2009).

    Google Scholar 

  55. Hanisco, T. F. et al. Observations of deep convective influence on stratospheric water vapor and its isotopic composition. Geophys. Res. Lett. 34, L04814 (2007).

    Google Scholar 

  56. Randel, W. J. et al. Global variations of HDO and HDO/H2O ratios in the UTLS derived from ACE-FTS satellite measurements. J. Geophys. Res. 117, D06303 (2012).

    Google Scholar 

  57. Dessler, A. E. & Sherwood, S. C. A model of HDO in the tropical tropopause layer. Atmos. Chem. Phys. 3, 2173–2181 (2003).

    Google Scholar 

  58. Grosvenor, D. P., Choularton, T. W., Coe, H. & Held, G. A study of the effect of overshooting deep convection on the water content of the TTL and lower stratosphere from Cloud Resolving Model simulations. Atmos. Chem. Phys. 7, 4977–5002 (2007).

    Google Scholar 

  59. Schiller, C. et al. Hydration and dehydration at the tropical tropopause. Atmos. Chem. Phys. 9, 9647–9660 (2009).

    Google Scholar 

  60. Wright, J. S., Fu, R., Fueglistaler, S., Liu, Y. S. & Zhang, Y., The influence of summertime convection over Southeast Asia on water vapor in the tropical stratosphere. J. Geophys. Res. 116, D12302 (2011).

    Google Scholar 

  61. Pommereau, J-P. et al. An overview of the HIBISCUS campaign. Atmos. Chem. Phys. 11, 2309–2339 (2011).

    Google Scholar 

  62. Minnis, P., Yost, C. R., Sun-Mack, S. & Chen, Y. Estimating the top altitude of optically thick ice clouds from thermal infrared satellite observations using CALIPSO data. Geophys. Res. Lett. 35, L12801 (2008).

    Google Scholar 

  63. Liu, C. & Zipser, E. J. Global distribution of tropical deep convection: Different perspectives from TRMM infrared and radar data. J. Clim. 20, 489–503 (2007).

    Google Scholar 

  64. Takahashi, H. & Luo, Z. Where is the level of neutral buoyancy for deep convection? Geophys. Res. Lett. 39, L15809 (2012).

    Google Scholar 

  65. Fueglistaler, S., Bonazzola, M., Haynes, P. H. & Peter, T. Stratospheric water vapor predicted from the Lagrangian temperature history of air entering the stratosphere in the tropics. J. Geophys. Res. 110, D08107 (2005).

    Google Scholar 

  66. Schoeberl, M. R. & Dessler, A. E. Dehydration of the stratosphere. Atmos. Chem. Phys. 11, 8433–8446 (2011).

    Google Scholar 

  67. Liu, Y. S., Fueglistaler, S. & Haynes P. H. Advection–condensation paradigm for stratospheric water vapor. J. Geophys. Res. 115, D24307 (2010).

    Google Scholar 

  68. Ploeger, F., Konopka, P., Günther, G., Gross, J-U. & Müller, R. Impact of the vertical velocity scheme on modeling transport in the tropical tropopause layer. J. Geophys. Res. 115, D03301 (2010).

    Google Scholar 

  69. Hartmann, D. L., Holton, J. R. & Fu, Q. The heat balance of the tropical tropopause, cirrus, and stratospheric dehydration. Geophys. Res. Lett. 28, 1969–1972 (2001).

    Google Scholar 

  70. Corti, T., Luo, B. P., Fu, Q., Vömel, H. & Peter, T. The impact of cirrus clouds on tropical troposphere-to-stratosphere transport. Atmos. Chem. Phys. 6, 2539–2547 (2006).

    Google Scholar 

  71. Schoeberl, M. R., Dessler, A. E. & Wang, T. Simulation of stratospheric water vapor trends using three reanalyses. Atmos. Chem. Phys. 12, 6475–6487 (2012).

    Google Scholar 

  72. Park, M., Randel, W. J., Gettelman, A., Massie, S. T. & Jiang, J. H. Transport above the Asian summer monsoon anticyclone inferred from Aura Microwave Limb Sounder tracers. J. Geophys. Res. 112, D16309 (2007).

    Google Scholar 

  73. Baker, A. K. et al. Characterization of non-methane hydrocarbon in Asian summer monsoon outflow observed by the CARIBIC aircraft. Atmos. Chem. Phys. 11, 503–518 (2011).

    Google Scholar 

  74. Vernier, J.-P., Thomason, L. W. & Kar, J. CALIPSO detection of an Asian tropopause aerosol layer. Geophys. Res. Lett. 38, L07804 (2011).

    Google Scholar 

  75. Randel, W. J. et al. Asian monsoon transport of pollution to the stratosphere. Science 328, 611–613 (2010).

    Google Scholar 

  76. Bourassa, A. E. et al. Large volcanic aerosol load in the stratosphere linked to Asian monsoon transport. Science 337, 78–81 (2012).

    Google Scholar 

  77. Koop, T., Luo, B., Tsias, A. & Peter, T. Water activity as the determinant for homogeneous ice nucleation in aqueous solutions. Nature 406, 611–614 (2000).

    Google Scholar 

  78. Jensen, E. J. & Pfister, L. Transport and freeze-drying in the tropical tropopause layer. J. Geophys. Res. 109, D02207 (2004).

    Google Scholar 

  79. Krämer, M. et al. Ice supersaturation and cirrus cloud crystal numbers. Atmos. Chem. Phys. 9, 3305–3522 (2009).

    Google Scholar 

  80. DeMott, P. J. et al. Measurements of the concentration and composition of ice nuclei for cirrus formation. Proc. Natl Acad. Sci. 100, 14655–14660 (2003).

    Google Scholar 

  81. Lawson . et al. Aircraft measurements of microphysical properties of subvisible cirrus clouds in the tropical tropopause layer. Atmos. Chem. Phys. 8, 1609–1620 (2008).

    Google Scholar 

  82. Oltmans, S. J. & Rosenlof, K. H. SPARC Assessment of Upper Tropospheric and Stratospheric Water Vapor (eds Kley, D., Russell, J. M. & Phillips, C.) (World Climate Research Program, 2000).

    Google Scholar 

  83. Weinstock, E. M. et al. Validation of the Harvard Lyman-α in situ water vapor instrument: Implications for the mechanisms that control stratospheric water vapor. J. Geophys. Res. 114, D23301 (2009).

    Google Scholar 

  84. Vömel, H. et al. Balloon-borne observations of water vapor and ozone in the tropical upper troposphere and lower stratosphere. J. Geophys. Res. 107, 4210 (2002).

    Google Scholar 

  85. Davis, S. et al. In situ and lidar observations of tropopause subvisible cirrus clouds during TC4. J. Geophys. Res. 115, D00J17 (2010).

    Google Scholar 

  86. Jensen, E. J. et al. Ice nucleation and dehydration in the tropical tropopause layer. Proc. Natl Acad. Sci. 110, 2041–2046 (2013).

    Google Scholar 

  87. Butchart, N. et al. Chemistry–climate model simulations of twenty-first century stratospheric climate and circulation changes. J. Clim. 23, 5349–5374 (2010).

    Google Scholar 

  88. Randel, W. J. & and Thompson, A. M. Interannual variability and trends in tropical ozone derived from SAGE II satellite data and SHADOZ ozonesondes. J. Geophys. Res. 116, D07303 (2011).

    Google Scholar 

  89. Free, M. The seasonal structure of temperature trends in the tropical lower stratosphere. J. Clim. 24, 859–866 (2011).

    Google Scholar 

  90. Hurst, D. F. et al. Stratospheric water vapor trends over Boulder, Colorado: Analysis of the 30 year Boulder record. J. Geophys. Res. 116, D02306 (2011).

    Google Scholar 

  91. Gettelman, A. et al. Multimodel assessment of the upper troposphere and lower stratosphere: Tropics and global trends. J. Geophys. Res. 115, D00M08 (2010).

    Google Scholar 

  92. Wang, J. S., Seidel, D. J. & Free, M. How well do we know recent climate trends at the tropical tropopause? J. Geophys. Res. 117, D09118 (2012).

    Google Scholar 

  93. Randel, W. J. in The Stratosphere: Dynamics, Transport and Chemistry (eds Polvani, L. M., Sobel, A. H. & Waugh, D. W.) 123–135 (Geophysical Monograph Series 190, American Geophysical Union, 2010).

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. National Center for Atmospheric Research, PO Box 3000, Boulder, 80307, Colorado, USA

    William J. Randel

  2. NASA Ames Research Center, Moffett Field, 94035, California, USA

    Eric J. Jensen

Authors
  1. William J. Randel
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Eric J. Jensen
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to William J. Randel.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Randel, W., Jensen, E. Physical processes in the tropical tropopause layer and their roles in a changing climate. Nature Geosci 6, 169–176 (2013). https://doi.org/10.1038/ngeo1733

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/ngeo1733

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing