Atmos. Chem. Phys. Discuss., 12, 28661-28703, 2012
www.atmos-chem-phys-discuss.net/12/28661/2012/
doi:10.5194/acpd-12-28661-2012
© Author(s) 2012. This work is distributed
under the Creative Commons Attribution 3.0 License.
Review Status
This discussion paper has been under review for the journal Atmospheric Chemistry and Physics (ACP). Please refer to the corresponding final paper in ACP.
Carbonaceous components, levoglucosan and inorganic ions in tropical aerosols from Tanzania, East Africa: implication for biomass burning contribution to organic aerosols
S. L. Mkoma1,2, K. Kawamura1, and P. Fu1,*
1Institute of Low Temperature Science, Hokkaido University, N19 W08, Kita-ku, Sapporo 060-0819, Japan
2Department of Physical Sciences, Faculty of Science, Sokoine University of Agriculture, P.O. Box 3038, Chuo Kikuu, Morogoro, Tanzania
*now at: LAPC, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China

Abstract. Atmospheric aerosol samples of PM2.5 and PM10 were collected at a rural site in Tanzania in 2011 during wet and dry seasons and they were analysed for carbonaceous components, levoglucosan and water-soluble inorganic ions. The mean mass concentrations of PM2.5 and PM10 were 28.2±6.4 μg m−3 and 47±8.2 μg m−3 in wet season, and 39.1±9.8 μg m−3 and 61.4±19.2 μg m−3 in dry season, respectively. Total carbon (TC) accounted for 16–19% of the PM2.5 mass and 13–15% of the PM10 mass. On average, 85.9 to 88.7% of TC in PM2.5 and 87.2 to 90.1% in PM10 was organic carbon (OC), of which 67–72% and 63% was found to be water-soluble organic carbon (WSOC) in PM2.5 and PM10, respectively. Water-soluble potassium (K+) and sulphate (SO42−) in PM2.5 and, sodium (Na+) and SO42− in PM10 were the dominant ionic species. We found, that concentrations of biomass burning tracers (levoglucosan and mannosan) well correlated with non-sea-salt-K+, WSOC and OC in the aerosols from Tanzania, East Africa. Mean contributions of levoglucosan to OC ranged between 3.9–4.2% for PM2.5 and 3.5–3.8% for PM10. This study demonstrates that emissions from biomass- and biofuel-burning activities followed by atmospheric photochemical processes mainly control the air quality in Tanzania.

Citation: Mkoma, S. L., Kawamura, K., and Fu, P.: Carbonaceous components, levoglucosan and inorganic ions in tropical aerosols from Tanzania, East Africa: implication for biomass burning contribution to organic aerosols, Atmos. Chem. Phys. Discuss., 12, 28661-28703, doi:10.5194/acpd-12-28661-2012, 2012.
 
Search ACPD
Discussion Paper
    XML
    Citation
    Final Revised Paper
    Share