Comprehensive isotopic composition of atmospheric nitrate in the Atlantic Ocean boundary layer from 65°S to 79°N - INSU - Institut national des sciences de l'Univers Access content directly
Journal Articles Journal of Geophysical Research: Atmospheres Year : 2009

Comprehensive isotopic composition of atmospheric nitrate in the Atlantic Ocean boundary layer from 65°S to 79°N

Abstract

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 δ 15N of nitrate mostly deriving from anthropogenically emitted NO x is found to be significantly different (from 0 to 6‰) from nitrate sampled in locations influenced by natural NO x sources (−4 ± 2)‰. The effects on δ 15N(NO3 −) of different NO x sources and nitrate removal processes associated with its atmospheric transport are discussed. Measurements of the oxygen isotope anomaly (Δ17O = δ 17O − 0.52 × δ 18O) of nitrate suggest that nocturnal processes involving the nitrate radical play a major role in terms of NO x sinks. Different Δ17O between aerosol size fractions indicate different proportions between nitrate formation pathways as a function of the size and composition of the particles. Extremely low δ 15N values (down to −40‰) are found in air masses exposed to snow-covered areas, showing that snowpack emissions of NO x from upwind regions can have a significant impact on the local surface budget of reactive nitrogen, in conjunction with interactions with active halogen chemistry. The implications of the results are discussed in light of the potential use of the stable isotopic composition of nitrate to infer atmospherically relevant information from nitrate preserved in ice cores.
Fichier principal
Vignette du fichier
ark _67375_WNG-XHBRVSLQ-0.pdf (1.44 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

insu-00413235 , version 1 (05-03-2021)

Identifiers

Cite

Samuel Morin, Joël Savarino, Markus M. Frey, Florent Domine, Hans-Werner Jacobi, et al.. Comprehensive isotopic composition of atmospheric nitrate in the Atlantic Ocean boundary layer from 65°S to 79°N. Journal of Geophysical Research: Atmospheres, 2009, 114, pp.D05303. ⟨10.1029/2008JD010696⟩. ⟨insu-00413235⟩
234 View
161 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More