Validation of Solar Occultation for Ice Experiment (SOFIE) nitric oxide measurements

Mark E. Hervig, Benjamin T. Marshall, Scott M. Bailey, David E. Siskind, James M. Russell III, Charles G. Bardeen, Kaley A. Walker, Bernd Funke
2019 Atmospheric Measurement Techniques  
<p><strong>Abstract.</strong> Nitric oxide (NO) measurements from the Solar Occultation for Ice Experiment (SOFIE) are validated through detailed uncertainty analysis and comparisons with independent observations. SOFIE was compared with coincident satellite measurements from the Atmospheric Chemistry Experiment (ACE) – Fourier Transform Spectrometer (FTS) instrument and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument. The comparisons indicate mean differences
more » ... mean differences of less than <span class="inline-formula">∼50</span>&amp;thinsp;% for altitudes from roughly 50 to 105&amp;thinsp;km for SOFIE spacecraft sunrise and 50 to 140&amp;thinsp;km for SOFIE sunsets. Comparisons of NO time series show a high degree of correlation between SOFIE and both ACE and MIPAS for altitudes below <span class="inline-formula">∼130</span>&amp;thinsp;km, indicating that measured NO variability in time is robust. SOFIE uncertainties increase below <span class="inline-formula">∼80</span>&amp;thinsp;km due to interfering <span class="inline-formula">H<sub>2</sub>O</span> absorption and signal correction uncertainties, which are larger for spacecraft sunrise compared to sunset. These errors are sufficiently large in sunrises that reliable NO measurements are infrequent below <span class="inline-formula">∼80</span>&amp;thinsp;km.</p>
doi:10.5194/amt-12-3111-2019 fatcat:hd5sjk5ug5do5mrcfmnzl2vmyq