Performance of the FMI cosine error correction method for the Brewer spectral UV measurements
Non-ideal angular response of a spectroradiometer is a well-known error source of spectral UV measurements and for that reason instrument specific cosine error correction is applied. In this paper, the performance of the cosine error correction method of Brewer spectral UV measurements in use at the...
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European Geosciences Union
2018
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Online Access: | https://hdl.handle.net/20.500.11765/11525 |
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ftaemet:oai:repositorio.aemet.es:20.500.11765/11525 2024-06-23T07:56:46+00:00 Performance of the FMI cosine error correction method for the Brewer spectral UV measurements Lakkala, Kaisa Arola, Antti Gröbner, Julian León-Luis, Sergio Fabián Redondas, Alberto Kazadzis, Stelios Karppinen, Tomi Karhu, Juha Matti Egli, Luca Heikkilä, Anu Koskela, Tapani Serrano, Antonio Vilaplana Guerrero, José Manuel 2018 https://hdl.handle.net/20.500.11765/11525 eng eng European Geosciences Union https://dx.doi.org/10.5194/amt-11-5167-2018 Atmospheric Measurement Techniques. 2018, 11(9), p. 5167–5180 1867-1381 1867-8548 http://hdl.handle.net/20.500.11765/11525 Licencia CC: Reconocimiento CC BY info:eu-repo/semantics/openAccess Brewer measurement Spectroradiometers Cosine error info:eu-repo/semantics/article 2018 ftaemet https://doi.org/20.500.11765/1152510.5194/amt-11-5167-2018 2024-06-03T14:17:57Z Non-ideal angular response of a spectroradiometer is a well-known error source of spectral UV measurements and for that reason instrument specific cosine error correction is applied. In this paper, the performance of the cosine error correction method of Brewer spectral UV measurements in use at the Finnish Meteorological Institute (FMI) is studied. Ideally, the correction depends on the actual sky radiation distribution, which can change even during one spectral scan due to rapid changes in cloudiness. The FMI method has been developed to take into account the changes in the ratio of direct to diffuse sky radiation and it derives a correction coefficient for each measured wavelength. Measurements of five Brewers were corrected for the cosine error and the results were compared to the reference travelling spectroradiometer (QASUME). Measurements were performed during the RBCC-E (Regional Brewer Calibration Center – Europe) X Campaign held at El Arenosillo, Huelva (37∘ N, 7∘ W), Spain, in 2015. In addition, results of site audits of FMI's Brewers in Sodankylä (67∘ N, 27∘ E) and Jokioinen (61∘ N, 24∘ E) during 2002–2014 were studied. The results show that the spectral cosine error correction varied between 4 and 14 %. After that the correction was applied to Brewer UV spectra the relative differences between the QASUME and the Brewer diminished even by 10 %. The study confirms that the method, originally developed for measurements at high latitudes, can be used at mid-latitudes as well. The method is applicable to other Brewers as far as the required input parameters, i.e. total ozone, aerosol information, albedo, instrument specific angular response and slit function are available. This article is based upon work from the COST Action ES1207 “A European Brewer Network (EUBREWNET)”, supported by COST (European Cooperation in Science and Technology). This study was partially supported by the research projects CGL2014-56255-C2-1-R and CGL2014-56255-C2-2-R granted by the Ministerio de Economa y Competitividad from ... Article in Journal/Newspaper Sodankylä ARCIMÍS (Archivo Climatológico y Meteorológico Institucional - AEMET, Agencia Estatal de Meteorología) Sodankylä ENVELOPE(26.600,26.600,67.417,67.417) Atmospheric Measurement Techniques 11 9 5167 5180 |
institution |
Open Polar |
collection |
ARCIMÍS (Archivo Climatológico y Meteorológico Institucional - AEMET, Agencia Estatal de Meteorología) |
op_collection_id |
ftaemet |
language |
English |
topic |
Brewer measurement Spectroradiometers Cosine error |
spellingShingle |
Brewer measurement Spectroradiometers Cosine error Lakkala, Kaisa Arola, Antti Gröbner, Julian León-Luis, Sergio Fabián Redondas, Alberto Kazadzis, Stelios Karppinen, Tomi Karhu, Juha Matti Egli, Luca Heikkilä, Anu Koskela, Tapani Serrano, Antonio Vilaplana Guerrero, José Manuel Performance of the FMI cosine error correction method for the Brewer spectral UV measurements |
topic_facet |
Brewer measurement Spectroradiometers Cosine error |
description |
Non-ideal angular response of a spectroradiometer is a well-known error source of spectral UV measurements and for that reason instrument specific cosine error correction is applied. In this paper, the performance of the cosine error correction method of Brewer spectral UV measurements in use at the Finnish Meteorological Institute (FMI) is studied. Ideally, the correction depends on the actual sky radiation distribution, which can change even during one spectral scan due to rapid changes in cloudiness. The FMI method has been developed to take into account the changes in the ratio of direct to diffuse sky radiation and it derives a correction coefficient for each measured wavelength. Measurements of five Brewers were corrected for the cosine error and the results were compared to the reference travelling spectroradiometer (QASUME). Measurements were performed during the RBCC-E (Regional Brewer Calibration Center – Europe) X Campaign held at El Arenosillo, Huelva (37∘ N, 7∘ W), Spain, in 2015. In addition, results of site audits of FMI's Brewers in Sodankylä (67∘ N, 27∘ E) and Jokioinen (61∘ N, 24∘ E) during 2002–2014 were studied. The results show that the spectral cosine error correction varied between 4 and 14 %. After that the correction was applied to Brewer UV spectra the relative differences between the QASUME and the Brewer diminished even by 10 %. The study confirms that the method, originally developed for measurements at high latitudes, can be used at mid-latitudes as well. The method is applicable to other Brewers as far as the required input parameters, i.e. total ozone, aerosol information, albedo, instrument specific angular response and slit function are available. This article is based upon work from the COST Action ES1207 “A European Brewer Network (EUBREWNET)”, supported by COST (European Cooperation in Science and Technology). This study was partially supported by the research projects CGL2014-56255-C2-1-R and CGL2014-56255-C2-2-R granted by the Ministerio de Economa y Competitividad from ... |
format |
Article in Journal/Newspaper |
author |
Lakkala, Kaisa Arola, Antti Gröbner, Julian León-Luis, Sergio Fabián Redondas, Alberto Kazadzis, Stelios Karppinen, Tomi Karhu, Juha Matti Egli, Luca Heikkilä, Anu Koskela, Tapani Serrano, Antonio Vilaplana Guerrero, José Manuel |
author_facet |
Lakkala, Kaisa Arola, Antti Gröbner, Julian León-Luis, Sergio Fabián Redondas, Alberto Kazadzis, Stelios Karppinen, Tomi Karhu, Juha Matti Egli, Luca Heikkilä, Anu Koskela, Tapani Serrano, Antonio Vilaplana Guerrero, José Manuel |
author_sort |
Lakkala, Kaisa |
title |
Performance of the FMI cosine error correction method for the Brewer spectral UV measurements |
title_short |
Performance of the FMI cosine error correction method for the Brewer spectral UV measurements |
title_full |
Performance of the FMI cosine error correction method for the Brewer spectral UV measurements |
title_fullStr |
Performance of the FMI cosine error correction method for the Brewer spectral UV measurements |
title_full_unstemmed |
Performance of the FMI cosine error correction method for the Brewer spectral UV measurements |
title_sort |
performance of the fmi cosine error correction method for the brewer spectral uv measurements |
publisher |
European Geosciences Union |
publishDate |
2018 |
url |
https://hdl.handle.net/20.500.11765/11525 |
long_lat |
ENVELOPE(26.600,26.600,67.417,67.417) |
geographic |
Sodankylä |
geographic_facet |
Sodankylä |
genre |
Sodankylä |
genre_facet |
Sodankylä |
op_relation |
https://dx.doi.org/10.5194/amt-11-5167-2018 Atmospheric Measurement Techniques. 2018, 11(9), p. 5167–5180 1867-1381 1867-8548 http://hdl.handle.net/20.500.11765/11525 |
op_rights |
Licencia CC: Reconocimiento CC BY info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/20.500.11765/1152510.5194/amt-11-5167-2018 |
container_title |
Atmospheric Measurement Techniques |
container_volume |
11 |
container_issue |
9 |
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5167 |
op_container_end_page |
5180 |
_version_ |
1802650081915043840 |