3 years ago

Trends in bromide wet deposition concentrations in the contiguous United States, 2001–2016

Trends in bromide wet deposition concentrations in the contiguous United States, 2001–2016
Bromide (Br) and other solute concentration data from wet deposition samples collected and analyzed by the National Atmospheric Deposition Program (NADP) from 2001 to 2016, were statistically analyzed for trends both geographically and temporally by precipitation type. Analysis was limited to NADP sites in the contiguous 48 United States. The Br concentrations for this time period had a high number of values censored at the detection limits with greater than 86 percent of sample concentrations below analytical detection. Bromide was more frequently detected at NADP sites in coastal regions. Analysis using specialized statistical techniques for censored data revealed that Br concentrations varied by precipitation type with higher concentrations usually observed in liquid versus precipitation containing snow. Negative temporal trends in Br wet deposition concentrations were observed at a majority of NADP sites; approximately 25 percent of these trend values were statistically significant at less than 0.05 to 0.10 significance levels. Potential causes for the negative trends were explored, including annual and seasonal changes in precipitation depth, reduced emissions of methyl bromide (CH3Br) from coastal wetlands, and declining industrial use of bromine compounds. The results indicate that Br in non-coastal wet-deposition comes mainly from long-range transport, not local sources. Correlations between Br, chloride, and nitrate concentrations also were evaluated.

Graphical abstract



Trends in bromide atmospheric wet deposition in the contiguous 48 U.S. for 2001–2016 reflect changes in brominated hydrocarbon emissions and precipitation depth.

Publisher URL: www.sciencedirect.com/science

DOI: S0269749117329391

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.