Diurnal Variability of Persistent Organic Pollutants in the Atmosphere over the Remote Southern Atlantic Ocean

Atmosphere

Rosalinda Gioia³  Matthew MacLeod²  Javier Castro-Jiménez⁴  Luca Nizzetto³  Jordi Dachs⁴  Rainer Lohmann¹ 

[1] Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882, USA; E-Mail:;Swiss Federal Institute of Technology, CH-8093 Zurich, Switzerland; E-Mail:;Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK; E-Mails:;Department of Environmental Chemistry, CSIC-IDAEA, Jordi Girona 18-24, E-08034 Barcelona, Spain; E-Mails:

关键词: persistent organic pollutants (POPs);    diurnal cycle;    polychlorinated biphenyls (PCBs);    polycyclic aromatic hydrocarbons (PAHs);    South Atlantic;   

DOI  :  10.3390/atmos5030622

来源: mdpi

【 摘 要 】

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.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.