Monitoring long-term trends in sulfate and ammonium in US precipitation: Results from the national atmospheric deposition program/national trends network

Christopher MB Lehmann, Van C. Bowersox, Robert S. Larson, Susan M Larson

Research output: Contribution to journalArticle

Abstract

Data from the National Atmospheric Deposition Program/National Trends Network (NADP/NTN) indicate significant changes have occurred in precipitation chemistry and the chemical climate in the United States (US). A Seasonal Kendall Trend (SKT) analysis shows statistically significant increases in precipitation ammonium concentrations at 64% of 159 continental US NADP/NTN sites evaluated from Winter 1985 to Fall 2004 (Dec. 1984 - Nov. 2004). Sulfate decreases were widespread, with an SKT analysis indicating statistically significant decreases at 89% of sites evaluated. Ratios of chemical equivalent concentrations of ammonium to sulfate in precipitation have risen to the extent that ammonium now exceeds sulfate over more than half of the continental U.S. on a precipitation-weighted-mean annual basis. These trends in the concentrations of ammonium, sulfate, and other species have been accompanied by significant decreases in the frequency of acidic precipitation (pH∈<∈5.0) in the last decade.

Original languageEnglish (US)
Pages (from-to)59-66
Number of pages8
JournalWater, Air, and Soil Pollution: Focus
Volume7
Issue number1-3
DOIs
StatePublished - Mar 1 2007

Fingerprint

atmospheric deposition
ammonium
trend analysis
sulfate
Monitoring
monitoring
precipitation (chemistry)
ammonium sulfate
winter
climate
long-term trend
programme
trend
Sulfates
chemical

Keywords

  • Chemical climate
  • Precipitation chemistry
  • Trend analysis

ASJC Scopus subject areas

  • Water Science and Technology
  • Pollution
  • Earth-Surface Processes
  • Earth and Planetary Sciences(all)

Cite this

@article{e89645b5768c47eaa153fa6db4a1276c,
title = "Monitoring long-term trends in sulfate and ammonium in US precipitation: Results from the national atmospheric deposition program/national trends network",
abstract = "Data from the National Atmospheric Deposition Program/National Trends Network (NADP/NTN) indicate significant changes have occurred in precipitation chemistry and the chemical climate in the United States (US). A Seasonal Kendall Trend (SKT) analysis shows statistically significant increases in precipitation ammonium concentrations at 64{\%} of 159 continental US NADP/NTN sites evaluated from Winter 1985 to Fall 2004 (Dec. 1984 - Nov. 2004). Sulfate decreases were widespread, with an SKT analysis indicating statistically significant decreases at 89{\%} of sites evaluated. Ratios of chemical equivalent concentrations of ammonium to sulfate in precipitation have risen to the extent that ammonium now exceeds sulfate over more than half of the continental U.S. on a precipitation-weighted-mean annual basis. These trends in the concentrations of ammonium, sulfate, and other species have been accompanied by significant decreases in the frequency of acidic precipitation (pH∈<∈5.0) in the last decade.",
keywords = "Chemical climate, Precipitation chemistry, Trend analysis",
author = "Lehmann, {Christopher MB} and Bowersox, {Van C.} and Larson, {Robert S.} and Larson, {Susan M}",
year = "2007",
month = "3",
day = "1",
doi = "10.1007/s11267-006-9100-z",
language = "English (US)",
volume = "7",
pages = "59--66",
journal = "Water, Air, and Soil Pollution: Focus",
issn = "1567-7230",
publisher = "Springer Netherlands",
number = "1-3",

}

TY - JOUR

T1 - Monitoring long-term trends in sulfate and ammonium in US precipitation

T2 - Results from the national atmospheric deposition program/national trends network

AU - Lehmann, Christopher MB

AU - Bowersox, Van C.

AU - Larson, Robert S.

AU - Larson, Susan M

PY - 2007/3/1

Y1 - 2007/3/1

N2 - Data from the National Atmospheric Deposition Program/National Trends Network (NADP/NTN) indicate significant changes have occurred in precipitation chemistry and the chemical climate in the United States (US). A Seasonal Kendall Trend (SKT) analysis shows statistically significant increases in precipitation ammonium concentrations at 64% of 159 continental US NADP/NTN sites evaluated from Winter 1985 to Fall 2004 (Dec. 1984 - Nov. 2004). Sulfate decreases were widespread, with an SKT analysis indicating statistically significant decreases at 89% of sites evaluated. Ratios of chemical equivalent concentrations of ammonium to sulfate in precipitation have risen to the extent that ammonium now exceeds sulfate over more than half of the continental U.S. on a precipitation-weighted-mean annual basis. These trends in the concentrations of ammonium, sulfate, and other species have been accompanied by significant decreases in the frequency of acidic precipitation (pH∈<∈5.0) in the last decade.

AB - Data from the National Atmospheric Deposition Program/National Trends Network (NADP/NTN) indicate significant changes have occurred in precipitation chemistry and the chemical climate in the United States (US). A Seasonal Kendall Trend (SKT) analysis shows statistically significant increases in precipitation ammonium concentrations at 64% of 159 continental US NADP/NTN sites evaluated from Winter 1985 to Fall 2004 (Dec. 1984 - Nov. 2004). Sulfate decreases were widespread, with an SKT analysis indicating statistically significant decreases at 89% of sites evaluated. Ratios of chemical equivalent concentrations of ammonium to sulfate in precipitation have risen to the extent that ammonium now exceeds sulfate over more than half of the continental U.S. on a precipitation-weighted-mean annual basis. These trends in the concentrations of ammonium, sulfate, and other species have been accompanied by significant decreases in the frequency of acidic precipitation (pH∈<∈5.0) in the last decade.

KW - Chemical climate

KW - Precipitation chemistry

KW - Trend analysis

UR - http://www.scopus.com/inward/record.url?scp=34247587129&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=34247587129&partnerID=8YFLogxK

U2 - 10.1007/s11267-006-9100-z

DO - 10.1007/s11267-006-9100-z

M3 - Article

AN - SCOPUS:34247587129

VL - 7

SP - 59

EP - 66

JO - Water, Air, and Soil Pollution: Focus

JF - Water, Air, and Soil Pollution: Focus

SN - 1567-7230

IS - 1-3

ER -