The HNO3 was measured by Ion Drift Chemical Ionization Mass Spectrometry. 
Only daytime measurements were available.   
The integration time was 0.8 sec and the reported data were 9 or 10 sec averaged.
Calibration was performed with commercial HNO3 permeation source. 
Detection limit was 0.2 ppbv based on one sigma.
Background signal was checked with sodium bicarbonate coated nylon filter.
Data points marked as "na" were due to either background check or spikes caused by discharge.  


The VOC data were measured by a compact PTR-MS (Ionicon Analytik).
It took about one minute to complete one scan cycle.
Background check was performed with zero air produced by catalytic converter.
The PTR-MS was calibrated with standard VOCs (Spectra Gas) including alkenes, aldehyde, ketones, and aromatic compounds.
The uncertainties associated with the reported VOC species were listed in row 3.
Gaps in the data set were due to background checks and calibrations.


If you are interested in our data, please contact Dr. Renyi Zhang at: 
1204 Eller O&M Building
Dept. Atmospheric Sciences
Texas A&M University
College Station, TX 77843-3150
Tel: (979)845-7656
Email: zhang@ariel.met.tamu.edu