A GCM Study of Volcanic Eruptions as a Cause of Increased Stratospheric Water Vapor

Manoj M. Joshi Department of Meteorology, University of Reading, Reading, United Kingdom

Search for other papers by Manoj M. Joshi in
Current site
Google Scholar
PubMed
Close
and
Keith P. Shine Department of Meteorology, University of Reading, Reading, United Kingdom

Search for other papers by Keith P. Shine in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Recent general circulation model (GCM) experiments have shown that idealized climatic perturbations that increase the temperature of the tropical tropopause region can cause larger than expected surface temperature increases. This is because the extra water vapor that is transported into the stratosphere acts as a positive radiative forcing agent. Since major volcanic eruptions in the Tropics also perturb temperatures in the region of the tropical tropopause, evidence is sought for the existence of such a mechanism by comparing model simulations and observations of the period following the eruption of Mount Pinatubo in 1991. Lower-stratosphere temperature perturbations are simulated using a GCM of intermediate complexity, and increases in water vapor concentration are found in the lower stratosphere that decay slowly in the years following the peak temperature increase. Such increases are consistent with the limited observations that exist over this period, as well as earlier work done with simpler 2D models. Since the amount of extra water transported into the stratosphere is sensitive to the absolute temperature change in the tropical tropopause region, this mechanism will be modulated by the phases of ENSO and the quasi-biennial oscillation, as well as being dependent on the vertical profile of the heating due to the volcanic aerosol. The global-mean radiative forcing associated with the perturbation in stratospheric water vapor is approximately +0.1 W m−2, and thus slightly counteracts the negative radiative forcing effect of the volcanic aerosol itself. It is suggested that repeated volcanic eruptions might at least partially account for increases in stratospheric water vapor over the last 40 years.

Corresponding author address: Manoj Joshi, Department of Meteorology, University of Reading, Earley Gate, P.O. Box 243, Reading RG6 6BB, United Kingdom. Email: m.m.joshi@reading.ac.uk

Abstract

Recent general circulation model (GCM) experiments have shown that idealized climatic perturbations that increase the temperature of the tropical tropopause region can cause larger than expected surface temperature increases. This is because the extra water vapor that is transported into the stratosphere acts as a positive radiative forcing agent. Since major volcanic eruptions in the Tropics also perturb temperatures in the region of the tropical tropopause, evidence is sought for the existence of such a mechanism by comparing model simulations and observations of the period following the eruption of Mount Pinatubo in 1991. Lower-stratosphere temperature perturbations are simulated using a GCM of intermediate complexity, and increases in water vapor concentration are found in the lower stratosphere that decay slowly in the years following the peak temperature increase. Such increases are consistent with the limited observations that exist over this period, as well as earlier work done with simpler 2D models. Since the amount of extra water transported into the stratosphere is sensitive to the absolute temperature change in the tropical tropopause region, this mechanism will be modulated by the phases of ENSO and the quasi-biennial oscillation, as well as being dependent on the vertical profile of the heating due to the volcanic aerosol. The global-mean radiative forcing associated with the perturbation in stratospheric water vapor is approximately +0.1 W m−2, and thus slightly counteracts the negative radiative forcing effect of the volcanic aerosol itself. It is suggested that repeated volcanic eruptions might at least partially account for increases in stratospheric water vapor over the last 40 years.

Corresponding author address: Manoj Joshi, Department of Meteorology, University of Reading, Earley Gate, P.O. Box 243, Reading RG6 6BB, United Kingdom. Email: m.m.joshi@reading.ac.uk

Save
  • Angell, J. K., 1997: Stratospheric warming due to Agung, El Chichón and Pinatubo taking into account the quasi-biennial oscillation. J. Geophys. Res., 102 , 94799485.

    • Search Google Scholar
    • Export Citation
  • Brewer, A. W., 1949: Evidence for a world circulation provided by the measurements of helium and water vapour distribution in the stratosphere. Quart. J. Roy. Meteor. Soc., 75 , 351363.

    • Search Google Scholar
    • Export Citation
  • Considine, D. B., J. E. Rosenfield, and E. L. Fleming, 2001: An interactive model study of the influence of the Mount Pinatubo aerosol on stratospheric methane and water trends. J. Geophys. Res., 106 , 2771127728.

    • Search Google Scholar
    • Export Citation
  • Dessler, A. E., 1998: A re-examination of the “stratospheric fountain” hypothesis. Geophys. Res. Lett., 25 , 41654168.

  • Elson, L. S., W. G. Read, J. W. Waters, P. W. Mote, J. S. Kinnersley, and R. S. Harwood, 1996: Space–time variations in water vapor as observed by the UARS microwave limb sounder. J. Geophys. Res., 101 , 90019015.

    • Search Google Scholar
    • Export Citation
  • Evans, S. J., R. Toumi, J. E. Harries, M. P. Chipperfield, and J. M. Russell III, 1998: Trends in stratospheric humidity and the sensitivity of ozone to these trends. J. Geophys. Res., 103 , 87158725.

    • Search Google Scholar
    • Export Citation
  • Forster, P. Mde F., and K. P. Shine, 2002: Assessing the climate impact of trends in stratospheric water vapor. Geophys. Res. Lett., 29 .1086, doi:10.1029/2001GL013909.

    • Search Google Scholar
    • Export Citation
  • Forster, P. Mde F., M. Blackburn, R. R. Glover, and K. P. Shine, 2000: An examination of climate sensitivity for idealised climate change experiments in an intermediate general circulation model. Climate Dyn., 16 , 833849.

    • Search Google Scholar
    • Export Citation
  • Geller, M. A., W. Zhou, and M. Zhang, 2002: Simulations of the interannual variability of stratospheric water vapor. J. Atmos. Sci., 59 , 10761085.

    • Search Google Scholar
    • Export Citation
  • Glaze, L. S., S. M. Baloga, and L. Wilson, 1997: Transport of atmospheric water vapour by volcanic eruption columns. J. Geophys. Res., 102 , 60996108.

    • Search Google Scholar
    • Export Citation
  • Hall, T. M., and D. W. Waugh, 1997: Timescales for the stratospheric circulation derived from tracers. J. Geophys. Res., 102 , 89919001.

    • Search Google Scholar
    • Export Citation
  • Harries, J. E., and Coauthors. 1996: Validation of measurements of water vapour from the Halogen Occultation Experiment (HALOE). J. Geophys. Res., 101 , 1020510216.

    • Search Google Scholar
    • Export Citation
  • Joshi, M. M., K. P. Shine, M. Ponater, N. Stuber, R. Sausen, and L. Li, 2003: A comparison of climate response to different radiative forcings in three General Circulation Models: Towards an improved metric of climate change. Climate Dyn., 20 , 843854.

    • Search Google Scholar
    • Export Citation
  • Kirchner, I., G. L. Stenchikov, H-F. Graf, A. Robock, and J. C. Antuña, 1999: Climate model simulation of winter warming and summer cooling following the 1991 Mount Pinatubo volcanic eruption. J. Geophys. Res., 104 , 1903919055.

    • Search Google Scholar
    • Export Citation
  • Kley, D., J. M. Russell III, and C. Phillips, Eds.,. 2000: SPARC assessment of upper tropospheric and stratospheric water vapor. SPARC Rep. 2, WMO/TD No. 1043, 241–246.

    • Search Google Scholar
    • Export Citation
  • Mastenbrook, H. J., and S. J. Oltmans, 1983: Stratospheric water vapor variability for Washington, DC/Boulder, CO:1964–82. J. Atmos. Sci., 40 , 21572165.

    • Search Google Scholar
    • Export Citation
  • Myhre, G., A. Myhre, and F. Stordal, 2001: Historical evolution of radiative forcing of climate. Atmos. Environ., 35 , 23612373.

  • Oltmans, S. J., H. Vömel, D. J. Hoffman, K. H. Rosenlof, and D. Kley, 2000: The increase in stratospheric water vapor from balloon borne frostpoint hygrometer measurements at Washington, DC and Boulder, Colorado. Geophys. Res. Lett., 27 , 34533456.

    • Search Google Scholar
    • Export Citation
  • Pinto, J. P., R. P. Turco, and O. B. Toon, 1989: Self-limiting physical and chemical effects in volcanic eruption clouds. J. Geophys. Res., 94 , 1116511174.

    • Search Google Scholar
    • Export Citation
  • Ramachandran, S., V. Ramaswamy, G. L. Stenchikov, and A. Robock, 2000: Radiative impact of the Mount Pinatubo volcanic eruption: Lower stratospheric response. J. Geophys. Res., 105 , 2440924429.

    • Search Google Scholar
    • Export Citation
  • Randel, W. J., F. Wu, and D. J. Gaffen, 2000: Interannual variability of the tropical tropopause derived from radiosonde data and NCEP reanalyses. J. Geophys. Res., 105 , 1550915523.

    • Search Google Scholar
    • Export Citation
  • Robock, A., 2000: Volcanic eruptions and climate. Rev. Geophys., 38 , 191219.

  • Rosenfield, J. E., D. B. Considine, M. R. Schoeberl, and E. V. Browell, 1998: The impact of subvisible cirrus clouds near the tropical tropopause on stratospheric water vapor. Geophys. Res. Lett., 25 , 18831886.

    • Search Google Scholar
    • Export Citation
  • Rosenlof, K. H., 2002: Transport changes inferred from HALOE water and methane measurements. J. Meteor. Soc. Japan, 80 , 831848.

  • Rosenlof, K. H., and Coauthors. 2001: Stratospheric water vapour increases over the past half-century. Geophys. Res. Lett., 28 , 11951198.

    • Search Google Scholar
    • Export Citation
  • Soden, B. J., R. T. Wetherald, G. L. Stenchikov, and A. Robock, 2002: Global cooling after the eruption of Mount Pinatubo: A test of climate feedback by water vapour. Science, 296 , 727730.

    • Search Google Scholar
    • Export Citation
  • Stenchikov, G. L., I. Kirchner, A. Robock, H-F. Graf, J. C. Antuña, R. G. Grainger, A. Lambert, and L. Thomason, 1998: Radiative forcing from the 1991 Mount Pinatubo volcanic eruption. J. Geophys. Res., 103 , 1383713857.

    • Search Google Scholar
    • Export Citation
  • Stuber, N., M. Ponater, and R. Sausen, 2001: Is the climate sensitivity to ozone perturbations enhanced by stratospheric water vapor feedback? Geophys. Res. Lett., 28 , 28872890.

    • Search Google Scholar
    • Export Citation
  • Yang, F., and M. E. Schlesinger, 2002: On the surface and atmospheric temperature changes following the 1991 Pinatubo volcanic eruption: A GCM study. J. Geophys. Res., 107 .4073, doi:10.1029/2001JD000373.

    • Search Google Scholar
    • Export Citation
  • Zhou, X., M. A. Geller, and M. Zhang, 2001: Tropical cold point tropopause characteristics derived from ECMWF reanalyses and soundings. J. Climate, 14 , 18231838.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 515 137 10
PDF Downloads 260 79 5