Nitrite Variability in Coastal North Carolina Rainwater and Its Impact on the Nitrogen Cycle in Rain

Abstract

The concentration range for nitrite (NO2 -) in 115 rain samples collected in Wilmington, NC, from June 1996 through February 1998 was 0.022−0.603 μM. Nitrite concentrations did not correlate with precipitation volume, suggesting a continuous supply of nitrite during rain events possibly by slow scavenging of gas-phase material such as HONO(g) or NO2(g) or in-cloud oxidation of other reduced forms of nitrogen. Nitrite levels exhibited no seasonal oscillations, which is in contrast to other rainwater parameters at this site such as pH, nitrate, non-seasalt sulfate (NSS) and ammonium. Concentrations of nitrite did not correlate with concentrations of pollutant indicators (pH, nitrate, and NSS). The concentration of nitrite in both winter El Nino rains and summer tropical rains was less than half its concentration in non-El Nino or non-tropical events, suggesting a possible terrestrial source of nitrite or nitrite precursor. Controlled laboratory studies demonstrated that hydrogen peroxide can oxidize nitrite in rainwater at environmentally relevant H+, H2O2, and NO2 - concentra tions. Nitrite oxidation by H2O2 in the aqueous phase has important ramifications with respect to N cycling and acid generation within the troposphere.

Composition of Dissolved Organic Nitrogen in Continental Precipitation Investigated by Ultra-High Resolution FT-ICR Mass Spectrometry

“…The inorganic N concentrations in these samples are consistent with those of other continental precipitation samples (2,(22)(23)(24)(25). The DON concentration is also consistent with concentrations reported for continental precipitation collected in the United States (29-38 µM), as is the contribution of DON to TDN (19-30%) (2, 12, 17, 26-28).…”

Bulk Atmospheric Deposition in the Charleston Harbor Watershed

“…This increase in production was attributed to atmospheric deposition of nitrates by Hurricane Diana (PAERL, 1985). However, KIEBER et al (1999) noted lower nitrate concentrations in precipitation samples collected for hurricanes Bertha and Fran, which is counter to our result for hurricane Opal. Sulfate and fluoride concentrations did not appear to be unusual for the samples collected for the Hurricane Opal rain event.…”

Isotopic composition of nitrate in sequential Hurricane Irene precipitation samples: Implications for changing NOx sources

“…3‰ (Kieber et al, 1999). The d 18 O values are relatively low compared to the reported range (þ63‰ to þ94‰) of~150 precipitation sites (n ¼ 883) across the U.S. but were similar to low values reported by the only other intra-rain event study reporting d 18 OeNO À 3 values (Buda and DeWalle, 2009).…”