Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 9 2 2009 10.5194/acpd-9-5447-2009 http://www.atmos-chem-phys-discuss.net/9/5447/2009/ http://www.atmos-chem-phys-discuss.net/9/5447/2009/acpd-9-5447-2009.html http://www.atmos-chem-phys-discuss.net/9/5447/2009/acpd-9-5447-2009.pdf 5447 5464 2009-03-02 The climatic effects of the direct injection of water vapour into the stratosphere by large volcanic eruptions M. M. Joshi m.m.joshi@reading.ac.uk G. S. Jones Walker Institute for Climate System Research, University of Reading, UK Hadley Centre for Climate Change, Met Office, UK We describe a novel mechanism that can significantly lower the amplitude of the climatic response to certain large volcanic eruptions. The proximity of oceans to some volcanoes can cause significant entrainment of water into coignimbrite clouds during the eruption. 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