\(NO_y\) includes all reactive nitrogen species. These species are: \(N\), \(NO\), \(NO_2\), \(NO_3\), \(N_2 O_5\), \(HNO_3\), \(HNO_4\), \(ClONO_2\) and \(BrONO_2\).

ACE-FTS data version 3.5 of five of these products ( \(NO\), \(NO_2\), \(N_2 O_5\), \(HNO_3\), \(ClONO_2\) ) has been validated against other satellite measurements such as: Global Ozone Monitoring by Occultation of Stars (GOMOS), Halogen Occultation Experiment (HALOE), Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (MAESTRO), Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), Microwave Limb Sounder (MLS), Optical Spectrograph and InfraRed Imaging System (OSIRIS), Polar Ozone and Aerosol Measurement (POAM) III, Stratospheric Aerosol and Gas Experiment (SAGE) III, SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY), Superconducting Submillimeter-Wave LimbEmission Sounder (SMILES), and Sub-Millimetre Radiometer (SMR).

Understanding the interactions of \(NO_y\) species is important due to their effect on ozone chemistry. The sources of \(NO_y\) in the stratosphere is through oxidation of \(N_2 O\). Energetic particle precipitation in the lower thermosphere creates \(NO\) and \(NO_2\) which then descend into the stratosphere during the Polar night.

The production and destruction of \(NO_y\) depend on sunlight and therefore its concentrations have large diurnal variations. To account for these diurnal variations, a photochemical box model was used to apply local time scaling to compare data between two instruments.

To compare the data sets of above mentioned instruments with ACE-FTS data, the profiles from each data set have been interpolated linearly onto the ACE-FTS 1 km grid and only the profiles closest in time to the ACE-FTS occultation have been used. Vertical resolution matching and a normalized Gaussian weighting was used. Details on the methodology can be found here. Some results from this study is presented:

\(NO\)

\(NO_2\)

\(N_2 O_5\)

\(HNO_3\)

\(ClONO_2\)

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References

Patrick E. Sheese, Kaley A. Walker, Chris D. Boone, Chris A. McLinden, Peter F. Bernath, Adam E. Bourassa, John P. Burrows , Doug A. Degenstein, Bernd Funke, Didier Fussen , Gloria L. Manney, C. Thomas McElroy, Donal Murtagh, Cora E. Randall, Piera Raspollini, Alexei Rozanov, James M. Russell III, Makoto Suzuki, Masato Shiotani, Joachim Urban, Thomas von Clarmann, and Joseph M. Zawodny; Validation of ACE-FTS version 3.5 \(NO_y\) species profiles using correlative satellite measurements, Atmos. Meas. Tech., 9, 5781–5810, 2016