Halogen emissions from a small volcanic eruption: modeling the peak concentrations, dispersion, and volcanically induced ozone loss in the stratosphere

Journal article

Aircraft measurements in the Hekla, Iceland volcanic plume in February 2000 revealed large quantities of hydrogen halides within the stratosphere correlated to volcanic SO₂. Investigation of the longer-term stratospheric impact of these emissions, using the 3D chemical transport model, SLIMCAT suggests that volcanic enhancements of H₂O and HNO₃ increased HNO₂ 3H₂O particle availability within the plume. These particles activated volcanic HCI and HBr, enhancing model plume concentrations of ClOₓ (20 ppb) and BrOₓ (50 ppt). Model O₃ concentrations decreased to near-zero in places, and plume average O₃ remained 30% lower after two weeks. Reductions in the model O₃ column reduced UV shielding by 15% for 2 days. Plume incorporation into the winter polar vortex after 1 March elevated model vortex Cl[sub>y and Br[sub>y by 0.15 ppb and 7 ppt respectively, and doubled vortex ClOₓ and BrO. Model results agree quantitatively with the observations made by the DC-8 aircraft.

Authors: Millard, G; Mather, T; Pyle, D; Rose, W; Thornton, B

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Geophysical Union
• Journal: Geophysical Research Letters
• Volume: 33
• Article number: L19815
• Publication date: 2006-10-01
• Edition: Publisher's version
• DOI: 10.1029/2006GL026959
• ISSN: 0094–8276
• Language: English
• Subjects: Earth sciences