The sources of primary and secondary aerosols in the Arctic are still poorly known. A number of surface seawater samples - with varying degrees of Arctic riverine and sea ice influences - were used in a sea spray generation chamber to test them for their potential to produce sea spray aerosols (SSA) and cloud condensation nuclei (CCN). Our interdisciplinary data showed that both sea salt and organic matter (OM) significantly influenced the SSA production. The number concentration of SSA in the coastal samples was negatively correlated with salinity and positively correlated with a number of OM tracers, including dissolved and chromophoric organic carbon (DOC, CDOM), marine microgels and chlorophyll a (Chl-a) but not for viral and bacterial abundances; indicating that OM of riverine origin enhances primary aerosol production. When all samples were considered, transparent exopolymer particles (TEP) were found to be the best indicator correlating positively with the ratio number concentration of SSA/salinity. CCN efficiency was not observed to differ between the SSA from the various samples, despite differences in organic characteristics. It is suggested that the large amount of freshwater from river runoff have a substantial impact on primary aerosols production mechanisms, possibly affecting the cloud radiative forcing.
Bibliographical noteFunding Information:
We are grateful to the captain and crews of R/V Araon for their enthusiastic assistance during the cruise of ARA08C. We would like to thank Dr. K. Sellegri (LaMP/CNRS, France) for lending the sea spray tank. We thank Eunho Jang (KOPRI, Korea) for providing the map of seawater sample locations. Marina Zamanillo (CSIC, Spain) helped with TEP and CSP analysis. This work was supported by a Korea Grant from the Korean Government (MSIP) (NRF-2016M1A5A1901769) (KOPRI-PN19081) and the KOPRI projects (PE17390 and PE19140). This research was supported by Project No. 20160247 funded by the Ministry of Oceans and Fisheries, Korea. The study was supported by the Spanish Ministry of Economy through project PI-ICE (CTM2017-89117-R) and the Ramony Cajal fellowship (RYC-2012-11922). SEANA (Shipping Emissions in the Arctic and North Atlantic Atmosphere), Reference NE/S00579 X /1 (PI Dr. Zongbo Shi), is also acknowledged. This work was partially supported by funding from the ICE-ARC programme from the European Union seventh Framework Programme, grant number 603887.
© 2019 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Environmental Chemistry