The Pandonia Global Network (PGN) consists of Pandora spectrometers that observe trace gases at a high time resolution to validate satellite observations and understand local air quality. To aid users, PGN assigns quality flags that assure scientifically valid data but eliminate large amounts of data appropriate for scientific applications. A new method based on contemporaneous data in two independent observation modes is proven using complementary ground-based and airborne observations.

We develop the Community Regional Atmospheric Chemistry Multiphase Mechanism (CRACMM) version 2 to improve predictions of formaldehyde in ambient air compared to satellite-, aircraft-, and ground-based observations. With the updated chemistry, we estimate the cancer risk from inhalation exposure to ambient formaldehyde across the contiguous USA and predict that 40 % of this risk is controllable through reductions in anthropogenic emissions of nitrogen oxides and reactive organic carbon.

We assess observed and modeled ozone weekend–weekday differences in the USA from 2002–2019. A subset of urban areas that were NO_x-saturated at the beginning of the period transitioned to NO_x-limited conditions. Multiple rural areas of California were NO_x-limited for the entire period but become less influenced by local day-of-week emission patterns in more recent years. The model produces more NO_x-saturated conditions than the observations but captures trends in weekend–weekday ozone patterns.

This manuscript details field and laboratory-based evaluations of ozone monitoring methods in smoke. UV photometry, the most widely used measurement method for ozone in ambient air, was shown to suffer from a severe positive interference when operated in the presence of smoke, while chemiluminescence-based methods were shown to be free of interferences. The results detailed in this paper will provide monitoring agencies with the tools needed to address smoke-related ozone measurement challenges.

Plastics are widely used in everyday life and scientific equipment. This paper presents Delrin plastic off-gassing as a function of temperature on the atmospheric measurements of formaldehyde by Pandora spectroscopic instruments. The sealed telescope assembly containing Delrin components emitted large amounts of formaldehyde at 30–45 °C, interfering with the Pandora measurements. These results have a broader implication since electronic products often experience the same temperature.