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HERO ID
3474826
Reference Type
Journal Article
Title
Increasing ammonia concentration trends in large regions of the USA derived from the NADP/AMoN network
Author(s)
Butler, T; Vermeylen, F; Lehmann, CM; Likens, GE; Puchalski, M
Year
2016
Is Peer Reviewed?
1
Journal
Atmospheric Environment
ISSN:
1352-2310
EISSN:
1873-2844
Volume
146
Page Numbers
132-140
DOI
10.1016/j.atmosenv.2016.06.033
Web of Science Id
WOS:000388051700012
Abstract
Data from bi-weekly passive samplers from 18 of the longest operating National Atmospheric Deposition Program's (NADP) Ammonia Monitoring Network (AMoN) sites (most operating from 2008 to 2015) show that concentrations of NH3 have been increasing (p-value < 0.0001) over large regions of the USA. This trend is occurring at a seasonal and annual level of aggregation. Using random coefficient models (RCM), the mean slope for the 18 sites combined shows an increase of NH3 concentration of +7% per year, with a 95% confidence interval (C.I.) from +5% to +9% per year. Travel blank corrected data using the same approach show increasing NH3 concentrations of +9% (95% C.I. +5% to +13%) per year. During a comparable period (2008-2014) NADP precipitation chemistry sites in the same regions show significant increasing (p-value = 0.0001) precipitation NH4+ concentrations trends for all sites combined of +5% (95% C.I. +3% to +7%) per year.
Emissions inventory data for the study period show nearly constant rates of NH3 emissions, but large reductions in NOx and SO2 emissions. Seasonal air quality data from the Clean Air Status and Trends Network (CASTNET) sites in these regions show significant declines in atmospheric particulate SO42- and NH4+, and particulate NO3- plus HNO3 (total NO3-) during the same period. Less formation of acidic SO4 and NO3, due to reduced SO2 and NOx emissions, provide less substrate to interact with NH3 and form particulate ammonium species. Thus, concentrations of NH3 can increase in the atmosphere even if emissions remain constant. A likely result may be more localized deposition of NH3, as opposed to the more long-range transport and deposition of ammonium nitrate (NH4NO3) and sulfate (NH4)(2)SO4). Additionally, the spatial distribution of wet and dry acidic deposition will be impacted. (C) 2016 Elsevier Ltd. All rights reserved.
Keywords
Reduced nitrogen; Ammonia emissions; Ammonia trends; Atmospheric nitrogen; Ammonia monitoring; Acid Rain 2015
Tags
IRIS
•
Nitrate/Nitrite
Broad LitSearch 2016/1/1 - 2017/12/5
Refs found by LitSearch but not ATSDR/IARC
Sodium, Potassium, & Ammonium Compounds
WoS
Refs found only by 2017 LitSearch or Citation Mapping
Ref Types 12/2017
All Others
LitSearch Update 2016-2017
WoS
•
ISA NOxSOxPM Ecology (2018)
Cited in the Second Draft
Appendix 2
•
ISA NOxSOxPM Ecology (2020- Final Project Page)
Cited
Appendix 2
•
LitSearch-NOx (2024)
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