Title Variability and trends in stratospheric NO2 in Antarctic summer, and implications for stratospheric NOy
Author Cook, P.A.; Roscoe, H.K.
Author Affil Cook, P.A., British Antarctic Survey, Cambridge, United Kingdom
Source Atmospheric Chemistry and Physics, 9(11), p.3601-3612, . Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1680- 7316
Publication Date 2009
Notes In English. Published in Atmospheric Chemistry and Physics Discussions: 12 January 2009, http://www.atmos-chem-phys- discuss.net/9/837/2009/acpd-9-837-2009.html; abstract: accessed in Apr., 2011. 24 refs. Ant. Acc. No: 91573. GeoRef Acc. No: 310574
Index Terms aerosols; climate; diurnal variations; ozone; statistical analysis; stratosphere; temperature; microelement content; Antarctica; Philippine Islands--Mount Pinatubo; Asia; atmosphere; Brewer-Dobson circulation; circulation; El Nino Southern Oscillation; eruptions; Far East; general circulation models; greenhouse gases; Luzon; Mount Pinatubo; nitrogen dioxide; Philippine Islands; regression analysis; Rossby waves; seasonal variations; solar cycles; trace elements; troposphere
Abstract NO2 measurements during 1990-2007, obtained from a zenith-sky spectrometer in the Antarctic, are analysed to determine the long-term changes in NO2. An atmospheric photochemical box model and a radiative transfer model are used to improve the accuracy of determination of the vertical columns from the slant column measurements, and to deduce the amount of NOy from NO2. We find that the NO2 and NOy columns in midsummer have large inter-annual variability superimposed on a broad maximum in 2000, with little or no overall trend over the full time period. These changes are robust to a variety of alternative settings when determining vertical columns from slant columns or determining NOy from NO2. They may signify similar changes in speed of the Brewer-Dobson circulation but with opposite sign, i.e. a broad minimum around 2000. Multiple regressions show significant correlation with solar and quasi-biennial-oscillation indices, and weak correlation with El Nino, but no significant overall trend, corresponding to an increase in Brewer-Dobson circulation of 1.43.5%/decade. There remains an unexplained cycle of amplitude and period at least 15% and 17 years, with minimum speed in about 2000.
URL http://www.atmos-chem-phys.net/9/3601/2009/acp-9-3601-2009.pdf
Publication Type journal article
Record ID 65007027