Amine nitrogen in the atmospheric environment over the North Atlantic Ocean


  • Krystyna Gorzelska,

  • James N. Galloway


During the course of the Global Change Expedition/Coordinated Air-Sea Experiment/Western Atlantic Ocean Experiment, we collected 77 aerosol and 20 precipitation samples over the North Atlantic Ocean; we speciated and quantified the organic nitrogen in these samples in the form of 18 different water-soluble primary amine compounds. We calculated the nitrogen contribution from these 18 amine species as the total amine nitrogen (TAN). Concentrations of TAN in aerosol samples ranged from 0.3 to 1630 pmol N m−3. Serine, glycine, arginine, alanine, ethanolamine, and methylamine contributed approximately 90% of TAN. Highest concentrations were in the samples collected near North America, Bermuda, the Azores, and in the Arctic Circle; low concentrations were in the samples collected in the Gulf Stream and in the equatorial North Atlantic. Radon concentrations, trajectory analyses, and correlations between different amine species provided clues to the origin and atmospheric history of these compounds. The long-range transport of terrestrial materials and oceanic inputs contributed to TAN. At low background concentrations, there was a statistically significant linear correlation between TAN and ammonium (NH4+) that persisted over the entire ocean area. Although their deposition flux may approach 10% of ammonium flux, relative to NH4+ the aerosol concentrations of the water-soluble primary amines were small (average=2%). The TAN in rain samples ranged from <5 to727 nM (average=164 nM). Generally, the amine species in precipitation paralleled those in aerosol. The scavenging ratio for individual species ranged from 200 to 3000.

Supplemental table is available with entire article on microfiche. Order from American Geophysical Union, 2000 Florida Avenue, N.W., Washington, D.C. 20009. Document G90-001; $2.50. Payment must accompany order.