Insights into summertime surface ozone formation from diurnal variations in formaldehyde and nitrogen dioxide along a transect through New York City

Estimating tropospheric ozone (O3) production from observations is challenging but possible given the close coupling of O3 with formaldehyde (HCHO) and nitrogen dioxide (NO2), two remotely sensed air pollutants. Previous reliance on once-daily satellite overpasses highlights the need to study diurnal changes and surface-column relationships. Using surface observations, Pandora spectrometer retrievals, and a high-resolution (1.33 km) air quality model (WRF-CMAQ), we characterize diurnal patterns of HCHO and NO2 at seven locations along an upwind-downwind pathway through NYC during June-August 2018. Diurnal patterns of the few available surface HCHO concentrations suggest biogenic emission influence, while a bimodal surface NO2 pattern implies local anthropogenic NOx emissions. Details of these patterns vary by site: an afternoon NO2 spike at New Haven (CT) indicates traffic emissions, while a delayed daily HCHO peak at Westport (CT) relative to other sites likely reflects sea breeze dyna..., We use version 5.3.1 Community Multiscale Air Quality Modeling System coupled online with version 4.1.1 Weather Research and Forecasting model (WRF-CMAQ) at 1.33 km by 1.33 km horizontal resolution. This simulation provided hourly preceding-hour-average estimates of surface HCHO, NO2, NO, CO, and O3 at the near-surface layer and instantaneous at-the-hour estimates of HCHO and NO2 in 36 vertical sigma pressure levels. WRF-CMAQ simulations are based on model specifications, emissions, and meteorology for the 1.33 km × 1.33 km simulation described in Torres-Vazquez et al. (2022). Emissions are sourced from the 2016 modeling platform version 7.2, based on the 2014 U.S. National Emissions Inventory (NEI) and the 2017 NEI with some additional sector-specific updates. Namely, on-road and non-road emissions were processed down to the county level for 21 counties in and around NYC for 2018 using the Motor Vehicle Emissions Simulator (MOVES) version 2014b. The inventory also incorporates updates ..., , # Data from: Insights into summertime surface ozone formation from diurnal variations in formaldehyde and nitrogen dioxide along a transect through New York City

[https://doi.org/10.5061/dryad.f7m0cfz3w](https://doi.org/10.5061/dryad.f7m0cfz3w)

## Description of the data and file structure

Source: Assembled and calculated by authors

This dataset comprises a series of CSV files generated from WRF-CMAQ simulations for June to August 2018 (JJA2018). The data capture variables across seven different sites, including planetary boundary layer heights, biogenic emissions, and both surface and column concentrations.

#### File Naming Convention

Files are named following the pattern: `Sitei_Hourly_data source_varname_JJA2018.csv`

\- `Sitei` represents the site name associated with the data.

\- `Hourly` indicates that the data was collected on an hourly basis.

\- `data source` and `varname` refer to the specific data source and variable names as described above.

#### Data Sources and Var...,