Title: Isotopes of reactive nitrogen species in mobile lab measurement during WE-CAN (Brown University)
Author(s): 
Jiajue Chai, orcid: 0000-0003-2818-0579, jiajue_chai@brown.edu, Brown University, Department of Earth, Environmental and Planetary Sciences, and Institute at Brown for Environment and Society, Assistant Professor of Research
Address: 324 Brook Street, Providence, RI 02912

Meredith Hastings (PI), orcid: 0000-0001-6716-6783, meredith_hastings@brown.edu, Brown University, Department of Earth, Environmental and Planetary Sciences, and Institute at Brown for Environment and Society, Professor
Address: 324 Brook Street, Box 1846, Providence, RI 02912

Data Set Overview:
This data set contains Brown/UNH NOAA mobile lab reactive nitrogen isotopes data collected during the WE-CAN (Western Wildfire Experiment for Cloud Chemistry, Aerosol, Absorption and Nitrogen) field campaign from 9 August through 18 August 2018. This data set is in ICARTT format. Please see the header portion of the data files for details on instruments, parameters, quality assurance, quality control, contact information, and data set comments. Area of interest covers Latitude from 44.504786 to 45.386971 and longitude from -114.233900 to -113.961868.

3 ICARTT files in total are uploaded and the titles are:
WECAN-MobileLab_NOx_Brown_20180809_RA
WECAN-MobileLab-Nitrate-Isotopes_Brown_20180809_RA
WECAN-MobileLab-RN-Isotopes_Brown_20180809_RA.

Please assign a DOI to our dataset.

Instrument Description:
NOx, HONO, p-NO3- and HNO3 were captured in the field using recently developed methods and sent to Brown University for offline analyses of isotopic composition (Jiajue Chai et al., 2019; Jiajue Chai & Hastings, 2018; Fibiger et al., 2014; Fibiger & Hastings, 2016). NOx concentrations were measured using a ThermoFisher chemiluminescence NOx analyzer. Collection time for HONO ranged from 2-12 hours and that for NOx ranged from 3/4 - 2 hours depending on their mixing ratios to make sure enough amount of samples were captured against blanks for isotopic analysis (Fibiger et al., 2014; Fibiger & Hastings, 2016; Wojtal et al., 2016). Particulate filter and Nylasorb filter were collected in 7-12 hours due to low concentration of particulate nitrate and HNO3. The samples from each collection systems were retrieved and processed following the procedures described in Chai et al. (2019) in a timely manner. The denitrifier method was used to complete nitrogen (15N/14N) and oxygen (18O/16O) isotope analyses of NO3- and/or NO2-, by quantitative conversion to N2O by denitrifying bacteria P. aureofaciens (Casciotti et al., 2002; Sigman et al., 2001). The isotopic composition of N2O is then determined by a Thermo Finnegan Delta V Plus isotope ratio mass spectrometer at m/z 44, 45 and 46 for 14N14N16O, 14N15N16O and 14N14N18O, respectively.

References
Casciotti, K. L., Sigman, D. M., Hastings, M. G., Böhlke, J. K., & Hilkert, A. (2002). Measurement of the Oxygen Isotopic Composition of Nitrate in Seawater and Freshwater Using the Denitrifier Method. Analytical Chemistry, 74(19), 4905–4912. https://doi.org/10.1021/ac020113w
Chai, J., Miller, D. J., Scheuer, E., Dibb, J., Selimovic, V., Yokelson, R., et al. (2019). Isotopic characterization of nitrogen oxides (NOx), nitrous acid (HONO), and nitrate (NO3-(p)) from laboratory biomass burning during FIREX. Atmos. Meas. Tech. Discuss., 2019, 1–32. https://doi.org/10.5194/amt-2019-229
Chai, Jiajue, & Hastings, M. G. (2018). Collection Method for Isotopic Analysis of Gaseous Nitrous Acid. Analytical Chemistry, 90(1), 830–838. https://doi.org/10.1021/acs.analchem.7b03561
Chai, Jiajue, Miller, D. J., Scheuer, E., Dibb, J., Selimovic, V., Yokelson, R., et al. (2019). Isotopic characterization of nitrogen oxides (NOx), nitrous acid (HONO), and nitrate (pNO3−) from laboratory biomass burning during FIREX. Atmospheric Measurement Techniques, 12(12), 6303–6317. https://doi.org/10.5194/amt-12-6303-2019
Fibiger, D. L., & Hastings, M. G. (2016). First Measurements of the Nitrogen Isotopic Composition of NOx from Biomass Burning. Environmental Science & Technology, 50(21), 11569–11574. https://doi.org/10.1021/acs.est.6b03510
Fibiger, D. L., Hastings, M. G., Lew, A. F., & Peltier, R. E. (2014). Collection of NO and NO2 for Isotopic Analysis of NOx Emissions. Analytical Chemistry, 86(24), 12115–12121. https://doi.org/10.1021/ac502968e
Sigman, D. M., Casciotti, K. L., Andreani, M., Barford, C., Galanter, M., & Böhlke, J. K. (2001). A Bacterial Method for the Nitrogen Isotopic Analysis of Nitrate in Seawater and Freshwater. Analytical Chemistry, 73(17), 4145–4153. https://doi.org/10.1021/ac010088e
Wojtal, P. K., Miller, D. J., O’Conner, M., Clark, S. C., & Hastings, M. G. (2016). Automated, High-resolution Mobile Collection System for the Nitrogen Isotopic Analysis of NOx. Journal of Visualized Experiments : JoVE, (118). https://doi.org/10.3791/54962