Atmospheric nitrate concentrations and isotope composition for samples collected in the marine boundary layer in 2006 and 2007 ...

• Main Authors: Morin, Samuel, Savarino, Joël, Frey, Markus M, Domine, Florent, Jacobi, Hans-Werner, Kaleschke, Lars, Martins, Jean MF
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2009
• Subjects: Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas SPP1158; Antarc*; Antarctic; Sea ice; Svalbard; Weddell Sea
• Online Access: https://dx.doi.org/10.1594/pangaea.848933; https://doi.pangaea.de/10.1594/PANGAEA.848933

The comprehensive isotopic composition of atmospheric nitrate (i.e., the simultaneous measurement of all its stable isotope ratios: 15N/14N, 17O/16O and 18O/16O) has been determined for aerosol samples collected in the marine boundary layer (MBL) over the Atlantic Ocean from 65°S (Weddell Sea) to 79°N (Svalbard), along a ship-borne latitudinal transect. In nonpolar areas, the d15N of nitrate mostly deriving from anthropogenically emitted NOx is found to be significantly different (from 0 to 6 per mil) from nitrate sampled in locations influenced by natural NOx sources (-4 ± 2) per mil. The effects on d15N(NO3-) of different NOx sources and nitrate removal processes associated with its atmospheric transport are discussed. Measurements of the oxygen isotope anomaly (D17O = d17O - 0.52 × d18O) of nitrate suggest that nocturnal processes involving the nitrate radical play a major role in terms of NOx sinks. Different D17O between aerosol size fractions indicate different proportions between nitrate formation ... : Supplement to: Morin, Samuel; Savarino, Joël; Frey, Markus M; Domine, Florent; Jacobi, Hans-Werner; Kaleschke, Lars; Martins, Jean MF (2009): Comprehensive isotopic composition of atmospheric nitrate in the Atlantic Ocean boundary layer from 65°S to 79°N. Journal of Geophysical Research, 114(D5) ...