Column Integrated Water Vapor and Aerosol Load Characterization with the New ZEN-R52 Radiometer

• Published in: Remote Sensing
• Main Authors: Almansa, Antonio Fernando, Cuevas-Agullo, Emilio, Barreto, África, Torres, Benjamin, Garcia, Omaira Elena, Garcia, Rosa Delia, Velasco-Merino, Cristian, Cachorro, Victoria Eugenia, Berjon, Alberto, Mallorquin, Manuel, Lopez, César, Ramos, Ramón, Guirado-Fuentes, Carmen, Negrillo, Ramón, de Frutos, Ángel Máximo
• Other Authors: Universidad de Valladolid Valladolid (UVa), Izaña Atmospheric Research Center (IARC), Agencia Estatal de Meteorología (AEMet), Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: precipitable water vapor; aerosol optical depth; zenith sky radiance; remote sensing; lookup table; radiative transfer; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Aerosol Robotic Network
• Online Access: https://hal.univ-lille.fr/hal-04459892; https://hal.univ-lille.fr/hal-04459892/document; https://hal.univ-lille.fr/hal-04459892/file/remotesensing-12-01424.pdf; https://doi.org/10.3390/rs12091424

International audience The study shows the first results of the column-integrated water vapor retrieved by the new ZEN-R52 radiometer. This new radiometer has been specifically designed to monitor aerosols and atmospheric water vapor with a high degree of autonomy and robustness in order to allow the expansion of the observations of these parameters to remote desert areas from ground-based platforms. The ZEN-R52 device shows substantial improvements compared to the previous ZEN-R41 prototype: a smaller field of view, an increased signal-to-noise ratio, better stray light rejection, and an additional channel (940 nm) for precipitable water vapor (PWV) retrieval. PWV is inferred from the ZEN-R52 Zenith Sky Radiance (ZSR) measurements using a lookup table (LUT) methodology. The improvement of the new ZEN-R52 in terms of ZSR was verified by means of a comparison with the ZEN-R41, and with the Aerosol Robotic Network (AERONET) Cimel CE318 (CE318-AERONET) at Izaña Observatory, a Global Atmosphere Watch (GAW) high mountain station (Tenerife, Canary Islands, Spain), over a 10-month period (August 2017 to June 2018). ZEN-R52 aerosol optical depth (AOD) was extracted by means of the ZEN–AOD–LUT method with an uncertainty of ±0.01 ± 0.13*AOD. ZEN-R52 PWV extracted using a new LUT technique was compared with quasi-simultaneous (±30 s) Fourier Transform Infrared (FTIR) spectrometer measurements as reference. A good agreement was found between the two instruments (PWV means a relative difference of 9.1% and an uncertainty of ±0.089 cm or ±0.036 + 0.061*PWV for PWV <1 cm). This comparison analysis was extended using two PWV datasets from the same CE318 reference instrument at Izaña Observatory: one obtained from AERONET (CE318-AERONET), and another one using a specific calibration of the 940-nm channel performed in this work at Izaña Atmospheric Research Center Observatory (CE318-IARC), which improves the PWV product.