Open AccessDiurnal and seasonal variation of atmospheric dimethylsulfoxide at Amsterdam Island in the southern Indian Ocean
Author(s) -
Sciare J.,
Kanakidou M.,
Mihalopoulos N.
Publication year - 2000
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1999jd901186
Subject(s) - diurnal temperature variation , mixing ratio , environmental science , aerosol , climatology , atmospheric sciences , diurnal cycle , seasonality , dimethyl sulfide , indian ocean , chemistry , meteorology , oceanography , geology , geography , sulfur , statistics , mathematics , organic chemistry
Atmospheric dimethylsulfoxide (DMSO), an important dimethylsulfide (DMS) oxidation by‐product, has been monitored on a daily basis at Amsterdam Island in the southern Indian Ocean during three periods (January–September 1997, January–June 1998, and January–October, 1999). In addition, during an intensive experiment carried out in January 1998, DMSO diurnal variation has been studied in conjunction with parallel measurements of atmospheric DMS. Monthly average atmospheric DMSO mixing ratios range from 0.3 to 5.8 parts per trillion by volume and present a well‐distinguished seasonal cycle with a minimum in winter and a maximum in summer similar to that observed for atmospheric DMS simultaneously measured. DMSO presents also a well‐distinguished diurnal variation with maximum values around 0900 and minimum during night. A photochemical box model using measured atmospheric DMS concentrations as input data reproduces quite well the diurnal variation of DMSO when assuming a 50% yield from the DMS+OH addition channel [ Hynes and Wine , 1996]. However, in absolute terms the simulated DMSO concentrations were about a factor of 2 higher than those measured. Photochemically driven heterogeneous losses of DMSO on aerosol and/or clouds could account for this difference.