This measurement report eloquently describes measurements of nitrogen oxides and other parameters needed to interpret factors contributing to the emission, chemistry and physical removal. The paper is exceptionally clear, the analysis clear and convincing and the interpretation persuasive. I recommend publication as is.

This study presents observations of NO, NO2, NOy, and O3 in a suburban temperate forest and highlights some important sources and sinks strongly affecting the nighttime chemistry of NOx. They found that the sustained high NO observed under very low O3 conditions could be attributed to the soil NO source, and the lack of nighttime NO2 increase can be related to its the nighttime deposition. Overall, this manuscript has comprehensively described their measurements and conducted an in-depth analysis on the observed nighttime NO2 behaviors in the Rambouillet forest environment. Although the authors didn’t employ box model to support their major conclusions, I do think the current analysis looks reasonable.

I only have a few minor issues. How about aerosol concentrations during the measurements? Does the uptake of NO2 on the aerosol surface affect the NO2 removal at night? I also suggest the authors to add a table to list their ground and tower measurements and this will be helpful for the readers. Lastly, I would encourage the authors to discuss about how to reduce the uncertainties in their estimated NO emissions.