Diurnal Variability of Persistent Organic Pollutants in the Atmosphere over the Remote Southern Atlantic Ocean
|Author(s)||Gioia Rosalinda1, 2, Macleod Matthew3, Castro-Jimenez Javier4, Nizzetto Luca1, 5, Dachs Jordi4, Lohmann Rainer6, Jones Kevin C.1|
|Affiliation(s)||1 : Univ Lancaster, Lancaster Environm Ctr, Lancaster LA1 4YQ, England.
2 : Cefas Lowestoft Lab, Ctr Environm Fisheries & Aquaculture Sci, Lowestoft NR33 0HT, Suffolk, England.
3 : Swiss Fed Inst Technol, CH-8093 Zurich, Switzerland.
4 : CSIC, IDAEA, Dept Environm Chem, E-08034 Barcelona, Spain.
5 : Norwegian Inst Water Res, NO-0349 Oslo, Norway.
6 : Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA.
|Source||Atmosphere (2073-4433) (Mdpi), 2014-09 , Vol. 5 , N. 3 , P. 622-634|
|WOS© Times Cited||1|
|Note||This article belongs to the Special Issue Persistent Organic Pollutants (POPs) in the Atmosphere: From Nowadays Background Sites to Hot Spots|
|Keyword(s)||persistent organic pollutants (POPs), diurnal cycle, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), South Atlantic|
A diel (24-h) cycle with daytime atmospheric concentrations higher than nighttime concentrations by a factor of 1.5-3 was observed for several low molecular weight polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in remote areas of the tropical South Atlantic during a cruise in October-November 2005. In contrast, high molecular weight PCBs and PAHs did not display diurnal variability. A model which has successfully explained diel variability of persistent organic pollutants (POPs) over land could not reproduce the observed diel cycle by considering variability in temperature, atmospheric OH radical concentrations, atmospheric boundary layer height and wind speed as causal factors. We used the model to conduct two bounding scenarios to explore the possibility that phytoplankton biomass turn-over in the surface ocean drives the observed variability in air concentrations. The model could only qualitatively reproduce the field observations of diel variability for low chlorinated PCB congeners when the ocean acts as a source of pollutants to the atmosphere, and when variability in biomass drives variability in the capacity of the surface ocean.