Daytime and nighttime aerosol optical depth implementation in CÆLIS

• Published in: Geoscientific Instrumentation, Methods and Data Systems
• Main Authors: R. González, C. Toledano, R. Román, D. Fuertes, A. Berjón, D. Mateos, C. Guirado-Fuentes, C. Velasco-Merino, J. C. Antuña-Sánchez, A. Calle, V. E. Cachorro, Á. M. de Frutos
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2020
• Subjects: Geophysics. Cosmic physics; QC801-809; Aerosol Robotic Network
• Online Access: https://doi.org/10.5194/gi-9-417-2020; https://doaj.org/article/87589e2eb2214d11bdaca4517207d30a

The University of Valladolid (UVa, Spain) has managed a calibration center of the AErosol RObotic NETwork (AERONET) since 2006. The CÆLIS software tool, developed by UVa, was created to manage the data generated by AERONET photometers for calibration, quality control and data processing purposes. This paper exploits the potential of this tool in order to obtain products like the aerosol optical depth (AOD) and Ångström exponent (AE), which are of high interest for atmospheric and climate studies, as well as to enhance the quality control of the instruments and data managed by CÆLIS. The AOD and cloud screening algorithms implemented in CÆLIS, both based on AERONET version 3, are described in detail. The obtained products are compared with the AERONET database. In general, the differences in daytime AOD between CÆLIS and AERONET are far below the expected uncertainty of the instrument, ranging in mean differences between <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">1.3</mn><mo>×</mo><msup><mn mathvariant="normal">10</mn><mrow><mo>-</mo><mn mathvariant="normal">4</mn></mrow></msup></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="59pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="388e97ab68d647ec5a81d523e6111574"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="gi-9-417-2020-ie00001.svg" width="59pt" height="14pt" src="gi-9-417-2020-ie00001.png"/></svg:svg> at 870 nm and <math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow><mn mathvariant="normal">6.2</mn><mo>×</mo><msup><mn mathvariant="normal">10</mn><mrow><mo>-</mo><mn ...