Trace gas data for Dead Run, Baltimore County, MD, USA

This resource includes trace gas data collected at three locations in the Dead Run stream network in Woodlawn, Baltimore County, MD. Dissolved gas species include CH4, N2O, CO2, and N2:Ar. Stream grab samples and ambient air samples are collected biweekly and analyzed for trace gas concentrations at the Cary Institute of Ecosystem Studies. Sampling stations are co-located with USGS stream gaging stations 01589312 (DR5), 01589315 (DR4), and 01589330 (DRKR). Protocols for sampling and analysis follow those of the National Ecological Observatory Network (NEON) and Cary Institute of Ecosystem Studies.

Dissolved gas measurements of streams coupled with groundwater can provide information on integrated source/sink dynamics within the urban critical zone. CO2 concentrations are driven by weathering reactions and biological activity. Nitrous oxide (N2O) is an index of nitrogen enrichment in the landscape. Methane (CH4) and dissolved nitrogen:argon (N2:Ar) indicate presence of anaerobic conditions and nitrogen sinks. Gas data can help determine the interplay between nitrogen inputs and processing in the urban critical zone. For example, high N2O (and nitrate) can provide evidence of a shift from a source-controlled to transport-controlled system. Low N2O (and low nitrate) along with high CH4 and high dissolved N2:Ar also can provide evidence of a similar shift but would suggest the presence of significant anaerobic sinks with implications about water pathways through the urban critical zone.