Examinando por Autor "Kivi, R."

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Acceso Abierto
Evaluation of Antarctic Ozone Profiles derived from OMPS-LP by using Balloon-borne Ozonesondes
(Nature Research Journals, 2021-02-22) Sepúlveda, E.; Cordero, R. R.; Damiani, A.; Feron, S.; Pizarro, J.; Zamorano, F.; Kivi, R.; Yela González, M.; Jumelet, J.; Godoy, A.; Carrasco, Jorge; Crespo, J. S.; Seckmeyer, G.; Jorquera, J. A.; Carrera, J. M.; Valdevenito, B.; Cabrera, S.; Redondas, A.; Rowe, P. M.; López Sánchez, Raúl; Chilean Antarctic Institute (INACH); Comisión Nacional de Investigación Científica y Tecnológica (CONICYT)
Predicting radiative forcing due to Antarctic stratospheric ozone recovery requires detecting changes in the ozone vertical distribution. In this endeavor, the Limb Profiler of the Ozone Mapping and Profiler Suite (OMPS-LP), aboard the Suomi NPP satellite, has played a key role providing ozone profiles over Antarctica since 2011. Here, we compare ozone profiles derived from OMPS-LP data (version 2.5 algorithm) with balloon-borne ozonesondes launched from 8 Antarctic stations over the period 2012–2020. Comparisons focus on the layer from 12.5 to 27.5 km and include ozone profiles retrieved during the Sudden Stratospheric Warming (SSW) event registered in Spring 2019. We found that, over the period December-January–February-March, the root mean square error (RMSE) tends to be larger (about 20%) in the lower stratosphere (12.5–17.5 km) and smaller (about 10%) within higher layers (17.5–27.5 km). During the ozone hole season (September–October–November), RMSE values rise up to 40% within the layer from 12.5 to 22 km. Nevertheless, relative to balloon-borne measurements, the mean bias error of OMPS-derived Antarctic ozone profiles is generally lower than 0.3 ppmv, regardless of the season.
Acceso Abierto
Ground-based validation of the Copernicus Sentinel-5P TROPOMI NO2 measurements with the NDACC ZSL-DOAS, MAX-DOAS and Pandonia global networks
(European Geoscience Union (EGU), 2021-01-22) Verhoelst, T.; Compernolle, S.; Pinardi, G.; Lambert, J. C.; Eskes, H. J.; Eichmann, K. U.; Fjaeraa, A. M.; Granville, J.; Niemeijer, S.; Cede, A.; Tiefengraber, M.; Hendrick, F.; Pazmiño, A.; Bais, A.; Bazureau, A.; Folkert Boersma, K.; Bognar, K.; Dehn, A.; Donner, S.; Elokhov, A.; Gebetsberger, M.; Goutail, F.; Grutter de la Mora, M.; Gruzdev, A.; Gratsea, M.; Hansen, G. H.; Irie, H.; Jepsen, N.; Kanaya, Y.; Karagkiozidis, D.; Kivi, R.; Kreher, K.; Levelt, P. F.; Liu, C.; Müller, M.; Piters, Ankie; Pommereau, J. P.; Portafaix, T.; Prados Roman, C.; Puentedura, O.; Querel, R.; Remmers, J.; Richter, A.; Rimmer, J.; Rivera Cárdenas, C.; Saavedra de Miguel, L.; Sinyakov, V. P.; Stremme, W.; Strong, K.; Van Roozendael, M.; Pepijn Veefkind, J.; Wagner, T.; Wittrock, F.; Yela González, M.; Zehner, C.; Navarro-Comas, Mónica; Navarro-Comas, Mónica; European Space Agency (ESA); French Institut National des Sciences de l'Univers (INSU); Centre National D'Etudes Spatiales (CNES); Centre National de la Recherche Scientifique (CNRS); Institut polaire français Paul Emile Victor (IPEV); Belgian Science Policy Office (BELSPO); Verhoelst, T. [0000-0003-0163-9984]; Compernolle, S. [0000-0003-0872-0961]; Pinardi, G. [0000-0001-5428-916X]; Eskes, H. [0000-0002-8743-4455]; Bais, A. [0000-0003-3899-2001]; Folkert Boersma, K. [0000-0002-4591-7635]; Bognar, K. [0000-0003-4619-2020]; Donner, S. [0000-0001-8868-167X]; Elokhov, A. [0000-0003-4725-9186]; Grutter de la Mora, M. [0000-0001-9800-5878]; Gruzdev, A. [0000-0003-3224-1012]; Karagkiozidis, D. [0000-0002-3595-0538]; Kivi, R. [0000-0001-8828-2759]; Liu, C. [0000-0002-3759-9219]; Müller, M. [0000-0001-5284-5425]; Pommereau, J. P. [0000-0002-8285-9526]; Prados Roman, C. [0000-0001-8332-0226]; Puentedura, O. [0000-0002-4286-1867]; Querel, R. [0000-0001-8792-2486]; Richter, A. [0000-0003-3339-212X]; Rivera Cárdenas, C. [0000-0002-8617-265X]; Stremme, W. [0000-0003-0791-3833]; Strong, K. [0000-0001-9947-1053]; Pepijn Veefkind, J. [0000-0003-0336-6406]
This paper reports on consolidated ground-based validation results of the atmospheric NO2 data produced operationally since April 2018 by the TROPOspheric Monitoring Instrument (TROPOMI) on board of the ESA/EU Copernicus Sentinel-5 Precursor (S5P) satellite. Tropospheric, stratospheric, and total NO2 column data from S5P are compared to correlative measurements collected from, respectively, 19 Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS), 26 Network for the Detection of Atmospheric Composition Change (NDACC) Zenith-Scattered-Light DOAS (ZSL-DOAS), and 25 Pandonia Global Network (PGN)/Pandora instruments distributed globally. The validation methodology gives special care to minimizing mismatch errors due to imperfect spatio-temporal co-location of the satellite and correlative data, e.g. by using tailored observation operators to account for differences in smoothing and in sampling of atmospheric structures and variability and photochemical modelling to reduce diurnal cycle effects. Compared to the ground-based measurements, S5P data show, on average, (i) a negative bias for the tropospheric column data, of typically −23 % to −37 % in clean to slightly polluted conditions but reaching values as high as −51 % over highly polluted areas; (ii) a slight negative median difference for the stratospheric column data, of about −0.2 Pmolec cm−2, i.e. approx. −2 % in summer to −15 % in winter; and (iii) a bias ranging from zero to −50 % for the total column data, found to depend on the amplitude of the total NO2 column, with small to slightly positive bias values for columns below 6 Pmolec cm−2 and negative values above. The dispersion between S5P and correlative measurements contains mostly random components, which remain within mission requirements for the stratospheric column data (0.5 Pmolec cm−2) but exceed those for the tropospheric column data (0.7 Pmolec cm−2). While a part of the biases and dispersion may be due to representativeness differences such as different area averaging and measurement times, it is known that errors in the S5P tropospheric columns exist due to shortcomings in the (horizontally coarse) a priori profile representation in the TM5-MP chemical transport model used in the S5P retrieval and, to a lesser extent, to the treatment of cloud effects and aerosols. Although considerable differences (up to 2 Pmolec cm−2 and more) are observed at single ground-pixel level, the near-real-time (NRTI) and offline (OFFL) versions of the S5P NO2 operational data processor provide similar NO2 column values and validation results when globally averaged, with the NRTI values being on average 0.79 % larger than the OFFL values.