Ammonia in the summertime Arctic marine boundary layer: sources, sinks and implications
International audience Continuous hourly measurements of gas-phase ammonia (NH 3(g) ) were taken from 13 July to 7 August 2014 on a research cruise throughout Baffin Bay and the eastern Canadian Arctic Archipelago. Concentrations ranged from 30-650 ng m -3 (40-870 pptv) with the highest values recor...
Main Authors: | , , , , , , , , , , , , , , |
---|---|
Other Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2015
|
Subjects: | |
Online Access: | https://hal.science/hal-04114694 https://doi.org/10.5194/acpd-15-29973-2015 |
id |
ftccsdartic:oai:HAL:hal-04114694v1 |
---|---|
record_format |
openpolar |
spelling |
ftccsdartic:oai:HAL:hal-04114694v1 2023-06-18T03:38:40+02:00 Ammonia in the summertime Arctic marine boundary layer: sources, sinks and implications Wentworth, G. R. Murphy, J. G. Croft, B. Martin, R. V. Pierce, J. R. Côté, J. -S. Courchesne, I. Tremblay, J. -É. Gagnon, J. Thomas, J. L. Sharma, S. Toom-Sauntry, D. Chivulescu, A. Levasseur, M. Abbatt, J. P. D. Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) 2015 https://hal.science/hal-04114694 https://doi.org/10.5194/acpd-15-29973-2015 en eng HAL CCSD info:eu-repo/semantics/altIdentifier/doi/10.5194/acpd-15-29973-2015 hal-04114694 https://hal.science/hal-04114694 BIBCODE: 2015ACPD.1529973W doi:10.5194/acpd-15-29973-2015 Atmospheric Chemistry and Physics Discussions https://hal.science/hal-04114694 Atmospheric Chemistry and Physics Discussions, 2015, 15, pp.29973-30016. ⟨10.5194/acpd-15-29973-2015⟩ [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2015 ftccsdartic https://doi.org/10.5194/acpd-15-29973-2015 2023-06-03T23:49:54Z International audience Continuous hourly measurements of gas-phase ammonia (NH 3(g) ) were taken from 13 July to 7 August 2014 on a research cruise throughout Baffin Bay and the eastern Canadian Arctic Archipelago. Concentrations ranged from 30-650 ng m -3 (40-870 pptv) with the highest values recorded in Lancaster Sound (74°13' N, 84°00' W). Simultaneous measurements of total ammonium ([NH x ]), pH and temperature in the ocean and in melt ponds were used to compute the compensation point (χ), which is the ambient NH 3(g) concentration at which surface-air fluxes change direction. Ambient NH 3(g) was usually several orders of magnitude larger than both χ ocean and χ MP (< 0.4-10 ng m 3 ) indicating these surface pools are net sinks of NH 3(g) . Flux calculations estimate average net downward fluxes of 1.4 and 1.1 ng m -2 s -1 for the open ocean and melt ponds, respectively. Sufficient NH 3(g) was present to neutralize non-sea salt sulphate (nss-SO 4 2- ) in the boundary layer during most of the study. This finding was corroborated with a historical dataset of PM 2.5 composition from Alert, NU (82°30' N, 62°20' W) wherein the median ratio of NH 4 + /nss-SO 4 2- equivalents was greater than 0.75 in June, July and August. The GEOS-Chem chemical transport model was employed to examine the impact of NH 3(g) emissions from seabird guano on boundary-layer composition and nss-SO 4 2- neutralization. A GEOS-Chem simulation without seabird emissions underestimated boundary layer NH 3(g) by several orders of magnitude and yielded highly acidic aerosol. A simulation that included seabird NH 3 emissions was in better agreement with observations for both NH 3(g) concentrations and nss-SO 4 2- neutralization. This is strong evidence that seabird colonies are significant sources of NH 3(g) in the summertime Arctic, and are ubiquitous enough to impact atmospheric composition across the entire Baffin Bay region. Large wildfires in the Northwest Territories were likely an important source of NH 3(g) , but their influence was ... Article in Journal/Newspaper Arctic Archipelago Arctic Baffin Bay Baffin Bay Baffin Canadian Arctic Archipelago Lancaster Sound Northwest Territories Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Arctic Northwest Territories Baffin Bay Canadian Arctic Archipelago Guano ENVELOPE(141.604,141.604,-66.775,-66.775) Lancaster Sound ENVELOPE(-83.999,-83.999,74.218,74.218) |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDU]Sciences of the Universe [physics] |
spellingShingle |
[SDU]Sciences of the Universe [physics] Wentworth, G. R. Murphy, J. G. Croft, B. Martin, R. V. Pierce, J. R. Côté, J. -S. Courchesne, I. Tremblay, J. -É. Gagnon, J. Thomas, J. L. Sharma, S. Toom-Sauntry, D. Chivulescu, A. Levasseur, M. Abbatt, J. P. D. Ammonia in the summertime Arctic marine boundary layer: sources, sinks and implications |
topic_facet |
[SDU]Sciences of the Universe [physics] |
description |
International audience Continuous hourly measurements of gas-phase ammonia (NH 3(g) ) were taken from 13 July to 7 August 2014 on a research cruise throughout Baffin Bay and the eastern Canadian Arctic Archipelago. Concentrations ranged from 30-650 ng m -3 (40-870 pptv) with the highest values recorded in Lancaster Sound (74°13' N, 84°00' W). Simultaneous measurements of total ammonium ([NH x ]), pH and temperature in the ocean and in melt ponds were used to compute the compensation point (χ), which is the ambient NH 3(g) concentration at which surface-air fluxes change direction. Ambient NH 3(g) was usually several orders of magnitude larger than both χ ocean and χ MP (< 0.4-10 ng m 3 ) indicating these surface pools are net sinks of NH 3(g) . Flux calculations estimate average net downward fluxes of 1.4 and 1.1 ng m -2 s -1 for the open ocean and melt ponds, respectively. Sufficient NH 3(g) was present to neutralize non-sea salt sulphate (nss-SO 4 2- ) in the boundary layer during most of the study. This finding was corroborated with a historical dataset of PM 2.5 composition from Alert, NU (82°30' N, 62°20' W) wherein the median ratio of NH 4 + /nss-SO 4 2- equivalents was greater than 0.75 in June, July and August. The GEOS-Chem chemical transport model was employed to examine the impact of NH 3(g) emissions from seabird guano on boundary-layer composition and nss-SO 4 2- neutralization. A GEOS-Chem simulation without seabird emissions underestimated boundary layer NH 3(g) by several orders of magnitude and yielded highly acidic aerosol. A simulation that included seabird NH 3 emissions was in better agreement with observations for both NH 3(g) concentrations and nss-SO 4 2- neutralization. This is strong evidence that seabird colonies are significant sources of NH 3(g) in the summertime Arctic, and are ubiquitous enough to impact atmospheric composition across the entire Baffin Bay region. Large wildfires in the Northwest Territories were likely an important source of NH 3(g) , but their influence was ... |
author2 |
Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Wentworth, G. R. Murphy, J. G. Croft, B. Martin, R. V. Pierce, J. R. Côté, J. -S. Courchesne, I. Tremblay, J. -É. Gagnon, J. Thomas, J. L. Sharma, S. Toom-Sauntry, D. Chivulescu, A. Levasseur, M. Abbatt, J. P. D. |
author_facet |
Wentworth, G. R. Murphy, J. G. Croft, B. Martin, R. V. Pierce, J. R. Côté, J. -S. Courchesne, I. Tremblay, J. -É. Gagnon, J. Thomas, J. L. Sharma, S. Toom-Sauntry, D. Chivulescu, A. Levasseur, M. Abbatt, J. P. D. |
author_sort |
Wentworth, G. R. |
title |
Ammonia in the summertime Arctic marine boundary layer: sources, sinks and implications |
title_short |
Ammonia in the summertime Arctic marine boundary layer: sources, sinks and implications |
title_full |
Ammonia in the summertime Arctic marine boundary layer: sources, sinks and implications |
title_fullStr |
Ammonia in the summertime Arctic marine boundary layer: sources, sinks and implications |
title_full_unstemmed |
Ammonia in the summertime Arctic marine boundary layer: sources, sinks and implications |
title_sort |
ammonia in the summertime arctic marine boundary layer: sources, sinks and implications |
publisher |
HAL CCSD |
publishDate |
2015 |
url |
https://hal.science/hal-04114694 https://doi.org/10.5194/acpd-15-29973-2015 |
long_lat |
ENVELOPE(141.604,141.604,-66.775,-66.775) ENVELOPE(-83.999,-83.999,74.218,74.218) |
geographic |
Arctic Northwest Territories Baffin Bay Canadian Arctic Archipelago Guano Lancaster Sound |
geographic_facet |
Arctic Northwest Territories Baffin Bay Canadian Arctic Archipelago Guano Lancaster Sound |
genre |
Arctic Archipelago Arctic Baffin Bay Baffin Bay Baffin Canadian Arctic Archipelago Lancaster Sound Northwest Territories |
genre_facet |
Arctic Archipelago Arctic Baffin Bay Baffin Bay Baffin Canadian Arctic Archipelago Lancaster Sound Northwest Territories |
op_source |
Atmospheric Chemistry and Physics Discussions https://hal.science/hal-04114694 Atmospheric Chemistry and Physics Discussions, 2015, 15, pp.29973-30016. ⟨10.5194/acpd-15-29973-2015⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/acpd-15-29973-2015 hal-04114694 https://hal.science/hal-04114694 BIBCODE: 2015ACPD.1529973W doi:10.5194/acpd-15-29973-2015 |
op_doi |
https://doi.org/10.5194/acpd-15-29973-2015 |
_version_ |
1769003567575728128 |