A comparison of OH nightglow volume emission rates as measured by SCIAMACHY and SABER

• Main Authors: Y. Zhu, M. Kaufmann, Q. Chen, J. Xu, Q. Gong, J. Liu, D. Wei, M. Riese
• Format: Article
• Language: English
• Published: Copernicus Publications 2020-06-01
• Series: Atmospheric Measurement Techniques
• Online Access: https://www.atmos-meas-tech.net/13/3033/2020/amt-13-3033-2020.pdf

<p>Hydroxyl (OH) short-wave infrared emissions arising from OH(4-2, 5-2, 8-5, 9-6) as measured by channel 6 of the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) are used to derive concentrations of OH(<span class="inline-formula"><i>v</i>=4</span>, 5, 8, and 9) between 80 and 96&thinsp;<span class="inline-formula">km</span>. Retrieved concentrations are used to simulate OH(5-3, 4-2) integrated radiances at 1.6&thinsp;<span class="inline-formula">µm</span> and OH(9-7, 8-6) at 2.0&thinsp;<span class="inline-formula">µm</span> as measured by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument, which are not fully covered by the spectral range of SCIAMACHY measurements. On average, SABER “unfiltered” data are on the order of 40&thinsp;<span class="inline-formula">%</span> at 1.6&thinsp;<span class="inline-formula">µm</span> and 20&thinsp;<span class="inline-formula">%</span> at 2.0&thinsp;<span class="inline-formula">µm</span> larger than the simulations using SCIAMACHY data. “Unfiltered” SABER data are a product, which accounts for the shape, width, and transmission of the instrument's broadband filters, which do not cover the full ro-vibrational bands of the corresponding OH transitions. It is found that the discrepancy between SCIAMACHY and SABER data can be reduced by up to 50&thinsp;<span class="inline-formula">%</span>, if the filtering process is carried out manually using published SABER interference filter characteristics and the latest Einstein coefficients from the HITRAN database. Remaining differences are discussed with regard to model parameter uncertainties and radiometric calibration.</p>