Tunable diode laser absorption spectrometer measurements of ambient nitrogen dioxide, nitric acid, formaldehyde, and hydrogen peroxide in Parlier, California

Field measurements were conducted to determine atmospheric concentrations of nitrogen dioxide, nitric acid, formaldehyde, and hydrogen peroxide gases using two dual-channel tunable diode laser absorption systems. These measurements were made as part of the Central California Ozone Study (CCOS) and were conducted for a total of 28 days from July to September 2000 at the Kearney Agricultural Research Station in Parlier, California. All four trace gases exhibit marked diurnal cycles. Ranges of measured concentrations: 1–38 ppb NO2, 0–26 ppb HNO3, 1–17 ppb HCHO, and 0–1.2 ppb H2O2. Formaldehyde, nitric acid and hydrogen peroxide mixing ratios showed unusual behavior during the last intensive measurement period in September 2000.