High-quality polar UV measurements : scientific analyses and transfer of the irradiance scale
The Earth's ecosystems are protected from the dangerous part of the solar ultraviolet (UV) radiation by stratospheric ozone, which absorbs most of the harmful UV wavelengths. Severe depletion of stratospheric ozone has been observed in the Antarctic region, and to a lesser extent in the Arctic...
Main Author: | |
---|---|
Other Authors: | , , , , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
Published: |
Helsingin yliopisto
2010
|
Subjects: | |
Online Access: | http://hdl.handle.net/10138/23154 |
id |
ftunivhelsihelda:oai:helda.helsinki.fi:10138/23154 |
---|---|
record_format |
openpolar |
spelling |
ftunivhelsihelda:oai:helda.helsinki.fi:10138/23154 2023-08-20T04:00:06+02:00 High-quality polar UV measurements : scientific analyses and transfer of the irradiance scale UV-mittaukset napa-alueilla : tieteellinen analyysi ja irradianssiskaalan siirto Lakkala, Kaisa Blumthaler, Mario University of Helsinki, Faculty of Science, Department of Physics, Division of Atmospheric Sciences Helsingin yliopisto, matemaattis-luonnontieteellinen tiedekunta, fysiikan laitos Helsingfors universitet, matematisk-naturvetenskapliga fakulteten, institutionen för fysik Kyrö, Esko 2010-11-25T14:08:40Z application/pdf http://hdl.handle.net/10138/23154 eng eng Helsingin yliopisto Helsingfors universitet University of Helsinki URN:ISBN:978-951-697-731-0 Yliopistopaino, Helsinki: 2010, Finnish Meteorological Institute Contributions. 0782-6117 http://hdl.handle.net/10138/23154 URN:ISBN:978-951-697-732-7 Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty. This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited. Publikationen är skyddad av upphovsrätten. Den får läsas och skrivas ut för personligt bruk. Användning i kommersiellt syfte är förbjuden. meteorologia Text Doctoral dissertation (article-based) Artikkeliväitöskirja Artikelavhandling doctoralThesis 2010 ftunivhelsihelda 2023-07-28T06:18:44Z The Earth's ecosystems are protected from the dangerous part of the solar ultraviolet (UV) radiation by stratospheric ozone, which absorbs most of the harmful UV wavelengths. Severe depletion of stratospheric ozone has been observed in the Antarctic region, and to a lesser extent in the Arctic and midlatitudes. Concern about the effects of increasing UV radiation on human beings and the natural environment has led to ground based monitoring of UV radiation. In order to achieve high-quality UV time series for scientific analyses, proper quality control (QC) and quality assurance (QA) procedures have to be followed. In this work, practices of QC and QA are developed for Brewer spectroradiometers and NILU-UV multifilter radiometers, which measure in the Arctic and Antarctic regions, respectively. These practices are applicable to other UV instruments as well. The spectral features and the effect of different factors affecting UV radiation were studied for the spectral UV time series at Sodankylä. The QA of the Finnish Meteorological Institute's (FMI) two Brewer spectroradiometers included daily maintenance, laboratory characterizations, the calculation of long-term spectral responsivity, data processing and quality assessment. New methods for the cosine correction, the temperature correction and the calculation of long-term changes of spectral responsivity were developed. Reconstructed UV irradiances were used as a QA tool for spectroradiometer data. The actual cosine correction factor was found to vary between 1.08-1.12 and 1.08-1.13. The temperature characterization showed a linear temperature dependence between the instrument's internal temperature and the photon counts per cycle. Both Brewers have participated in international spectroradiometer comparisons and have shown good stability. The differences between the Brewers and the portable reference spectroradiometer QASUME have been within 5% during 2002-2010. The features of the spectral UV radiation time series at Sodankylä were analysed for the time period ... Doctoral or Postdoctoral Thesis Antarc* Antarctic Arctic Sodankylä Helsingfors Universitet: HELDA – Helsingin yliopiston digitaalinen arkisto Arctic Antarctic The Antarctic Sodankylä ENVELOPE(26.600,26.600,67.417,67.417) |
institution |
Open Polar |
collection |
Helsingfors Universitet: HELDA – Helsingin yliopiston digitaalinen arkisto |
op_collection_id |
ftunivhelsihelda |
language |
English |
topic |
meteorologia |
spellingShingle |
meteorologia Lakkala, Kaisa High-quality polar UV measurements : scientific analyses and transfer of the irradiance scale |
topic_facet |
meteorologia |
description |
The Earth's ecosystems are protected from the dangerous part of the solar ultraviolet (UV) radiation by stratospheric ozone, which absorbs most of the harmful UV wavelengths. Severe depletion of stratospheric ozone has been observed in the Antarctic region, and to a lesser extent in the Arctic and midlatitudes. Concern about the effects of increasing UV radiation on human beings and the natural environment has led to ground based monitoring of UV radiation. In order to achieve high-quality UV time series for scientific analyses, proper quality control (QC) and quality assurance (QA) procedures have to be followed. In this work, practices of QC and QA are developed for Brewer spectroradiometers and NILU-UV multifilter radiometers, which measure in the Arctic and Antarctic regions, respectively. These practices are applicable to other UV instruments as well. The spectral features and the effect of different factors affecting UV radiation were studied for the spectral UV time series at Sodankylä. The QA of the Finnish Meteorological Institute's (FMI) two Brewer spectroradiometers included daily maintenance, laboratory characterizations, the calculation of long-term spectral responsivity, data processing and quality assessment. New methods for the cosine correction, the temperature correction and the calculation of long-term changes of spectral responsivity were developed. Reconstructed UV irradiances were used as a QA tool for spectroradiometer data. The actual cosine correction factor was found to vary between 1.08-1.12 and 1.08-1.13. The temperature characterization showed a linear temperature dependence between the instrument's internal temperature and the photon counts per cycle. Both Brewers have participated in international spectroradiometer comparisons and have shown good stability. The differences between the Brewers and the portable reference spectroradiometer QASUME have been within 5% during 2002-2010. The features of the spectral UV radiation time series at Sodankylä were analysed for the time period ... |
author2 |
Blumthaler, Mario University of Helsinki, Faculty of Science, Department of Physics, Division of Atmospheric Sciences Helsingin yliopisto, matemaattis-luonnontieteellinen tiedekunta, fysiikan laitos Helsingfors universitet, matematisk-naturvetenskapliga fakulteten, institutionen för fysik Kyrö, Esko |
format |
Doctoral or Postdoctoral Thesis |
author |
Lakkala, Kaisa |
author_facet |
Lakkala, Kaisa |
author_sort |
Lakkala, Kaisa |
title |
High-quality polar UV measurements : scientific analyses and transfer of the irradiance scale |
title_short |
High-quality polar UV measurements : scientific analyses and transfer of the irradiance scale |
title_full |
High-quality polar UV measurements : scientific analyses and transfer of the irradiance scale |
title_fullStr |
High-quality polar UV measurements : scientific analyses and transfer of the irradiance scale |
title_full_unstemmed |
High-quality polar UV measurements : scientific analyses and transfer of the irradiance scale |
title_sort |
high-quality polar uv measurements : scientific analyses and transfer of the irradiance scale |
publisher |
Helsingin yliopisto |
publishDate |
2010 |
url |
http://hdl.handle.net/10138/23154 |
long_lat |
ENVELOPE(26.600,26.600,67.417,67.417) |
geographic |
Arctic Antarctic The Antarctic Sodankylä |
geographic_facet |
Arctic Antarctic The Antarctic Sodankylä |
genre |
Antarc* Antarctic Arctic Sodankylä |
genre_facet |
Antarc* Antarctic Arctic Sodankylä |
op_relation |
URN:ISBN:978-951-697-731-0 Yliopistopaino, Helsinki: 2010, Finnish Meteorological Institute Contributions. 0782-6117 http://hdl.handle.net/10138/23154 URN:ISBN:978-951-697-732-7 |
op_rights |
Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty. This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited. Publikationen är skyddad av upphovsrätten. Den får läsas och skrivas ut för personligt bruk. Användning i kommersiellt syfte är förbjuden. |
_version_ |
1774716692638728192 |