Validation of the TROPOspheric Monitoring Instrument (TROPOMI) surface UV radiation product

• Published in: Atmospheric Measurement Techniques
• Main Authors: Lakkala, Kaisa, Kujanpää, Jukka, Brogniez, Colette, HENRIOT, Nicolas, Arola, Antti, Aun, Margit, Auriol, Frédérique, Bais, Alkiviadis, Bernhard, Germar, De Bock, Veerle, Catalfamo, Maxime, Deroo, Christine, Diémoz, Henri, Egli, Luca, Forestier, Jean-Baptiste, Fountoulakis, Ilias, Garane, Katerina, Garcia, Rosa, Gröbner, Julian, Hassinen, Seppo, Heikkilä, Anu, Henderson, Stuart, Hülsen, Gregor, Johnsen, Bjørn, Kalakoski, Niilo, Karanikolas, Angelos, Karppinen, Tomi, Lamy, Kevin, León-Luis, Sergio, Lindfors, Anders, Metzger, Jean-Marc, Minvielle, Fanny, Muskatel, Harel, Portafaix, Thierry, Redondas, Alberto, Sanchez, Ricardo, Siani, Anna, Svendby, Tove, Tamminen, Johanna
• Other Authors: Space and Earth Observation Centre Sodankylä, Finnish Meteorological Institute (FMI), 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), Aristotle University of Thessaloniki, Biospherical Instruments Inc., Institut Royal Météorologique de Belgique Bruxelles (IRM), Aosta Valley Regional Environmental Protection Agency (ARPA), CNR Institute of Atmospheric Sciences and Climate (ISAC), Consiglio Nazionale delle Ricerche (CNR), Physical-Meteorological Observatory/World Radiation Center, Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Atmospheric Optics Group of the University of Valladolid (GOA-UVA), Universidad de Valladolid Valladolid (UVa), Australian Radiation Protection and Nuclear Safety Agency, Norwegian Radiation and Nuclear Safety Authority, Izaña Atmospheric Research Center (IARC), Agencia Estatal de Meteorología (AEMet), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Israel Meteorological Service, Università degli Studi di Roma "La Sapienza" = Sapienza University Rome, Norwegian Institute for Air Research (NILU), The UV-Indien programme has been supported by the European Union through the PO INTERREG V, by the Reunion Island Council and by the French Government. The OPAR station (Observatoire de Physique de l’Atmosphèrede La Réunion) and the OSUR activities are funded by the Université de LaRéunion and CNRS. Measurements of French spectroradiometers are supported by CNES (within the French programme TOSCA); the Région Hauts-de-France and the Ministère de l’Enseignement Supérieur et de la Recherche (CPER Climibio); and the European Fund for Regional Economic Development. GUV measurements at Blindern, Ny-Ålesund and Andøya are funded by the Norwegian Environment Agency. Kaisa Lakkala is supported by the CHAMPS project (grant no. 329225) of the Academy of Finland under the CLIHE programme.
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Antarctic; Arctic; The Sentinel; albedo; Antarc*; Subarctic
• Online Access: https://hal.univ-reunion.fr/hal-03132348; https://hal.univ-reunion.fr/hal-03132348/document; https://hal.univ-reunion.fr/hal-03132348/file/amt-13-6999-2020.pdf; https://doi.org/10.5194/amt-13-6999-2020

International audience The TROPOspheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5 Precursor (S5P) satellite was launched on 13 October 2017 to provide the atmospheric composition for atmosphere and climate research. The S5P is a Sun-synchronous polar-orbiting satellite providing global daily coverage. The TROPOMI swath is 2600 km wide, and the ground resolution for most data products is 7:2 3:5 km2 (5:6 3:5 km2 since 6 August 2019) at nadir. The Finnish Meteorological Institute (FMI) is responsible for the development of the TROPOMI UV algorithm and the processing of the TROPOMI surface ultraviolet (UV) radiation product which includes 36 UV parameters in total. Ground-based data from 25 sites located in arctic, subarctic, temperate, equatorial and Antarctic areas were used for validation of the TROPOMI overpass irradiance at 305, 310, 324 and 380 nm, overpass erythemally weighted dose rate/UV index, and erythemally weighted daily dose for the period from 1 January 2018 to 31 August 2019. The validation results showed that for most sites 60 %–80% of TROPOMI data was within 20% of ground-based data for snow-free surface conditions. The median relative differences to ground-based measurements of TROPOMI snow-free surface daily doses were within 10% and 5% at two-thirds and at half of the sites, respectively. At several sites more than 90% of cloud-free TROPOMI data was within 20% of groundbased measurements. Generally median relative differences between TROPOMI data and ground-based measurements were a little biased towards negative values (i.e. satellite data<ground-based measurement), but at high latitudes where non-homogeneous topography and albedo or snow conditions occurred, the negative bias was exceptionally high: from 30% to 65 %. Positive biases of 10 %–15% were also found for mountainous sites due to challenging topography. The TROPOMI surface UV radiation product includes quality flags to detect increased uncertainties in the data due to heterogeneous surface albedo and rough terrain, ...