Algorithms and uncertainties for the determination of multispectral irradiance components and aerosol optical depth from a shipborne rotating shadowband radiometer
The 19-channel rotating shadowband radiometer GUVis-3511 built by Biospherical Instruments provides automated shipborne measurements of the direct, diffuse and global spectral irradiance components without a requirement for platform stabilization. Several direct sun products, including spectral dire...
Main Authors: | , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Katlenburg-Lindau : Copernicus
2017
|
Subjects: | |
Online Access: | https://oa.tib.eu/renate/handle/123456789/11530 https://doi.org/10.34657/10564 |
id |
ftleibnizopen:oai:oai.leibnizopen.de:ojiIYIgBdbrxVwz6n0BL |
---|---|
record_format |
openpolar |
spelling |
ftleibnizopen:oai:oai.leibnizopen.de:ojiIYIgBdbrxVwz6n0BL 2023-06-11T04:03:05+02:00 Algorithms and uncertainties for the determination of multispectral irradiance components and aerosol optical depth from a shipborne rotating shadowband radiometer Witthuhn, Jonas Deneke, Hartwig Macke, Andreas Bernhard, Germar 2017 application/pdf https://oa.tib.eu/renate/handle/123456789/11530 https://doi.org/10.34657/10564 eng eng Katlenburg-Lindau : Copernicus CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0 Atmospheric measurement techniques : AMT 10 (2017), Nr. 2 aerosol property algorithm calibration confidence interval irradiance optical depth precipitable water radiometer Rayleigh number scattering shipborne measurement spectral analysis transmittance uncertainty analysis water vapor 550 article Text 2017 ftleibnizopen https://doi.org/10.34657/10564 2023-05-28T23:36:30Z The 19-channel rotating shadowband radiometer GUVis-3511 built by Biospherical Instruments provides automated shipborne measurements of the direct, diffuse and global spectral irradiance components without a requirement for platform stabilization. Several direct sun products, including spectral direct beam transmittance, aerosol optical depth, Ångström exponent and precipitable water, can be derived from these observations. The individual steps of the data analysis are described, and the different sources of uncertainty are discussed. The total uncertainty of the observed direct beam transmittances is estimated to be about 4% for most channels within a 95% confidence interval for shipborne operation. The calibration is identified as the dominating contribution to the total uncertainty. A comparison of direct beam transmittance with those obtained from a Cimel sunphotometer at a land site and a manually operated Microtops II sunphotometer on a ship is presented. Measurements deviate by less than 3 and 4% on land and on ship, respectively, for most channels and in agreement with our previous uncertainty estimate. These numbers demonstrate that the instrument is well suited for shipborne operation, and the applied methods for motion correction work accurately. Based on spectral direct beam transmittance, aerosol optical depth can be retrieved with an uncertainty of 0.02 for all channels within a 95% confidence interval. The different methods to account for Rayleigh scattering and gas absorption in our scheme and in the Aerosol Robotic Network processing for Cimel sunphotometers lead to minor deviations. Relying on the cross calibration of the 940 nm water vapor channel with the Cimel sunphotometer, the column amount of precipitable water can be estimated with an uncertainty of ±0.034 cm. publishedVersion Article in Journal/Newspaper Aerosol Robotic Network LeibnizOpen (The Leibniz Association) |
institution |
Open Polar |
collection |
LeibnizOpen (The Leibniz Association) |
op_collection_id |
ftleibnizopen |
language |
English |
topic |
aerosol property algorithm calibration confidence interval irradiance optical depth precipitable water radiometer Rayleigh number scattering shipborne measurement spectral analysis transmittance uncertainty analysis water vapor 550 |
spellingShingle |
aerosol property algorithm calibration confidence interval irradiance optical depth precipitable water radiometer Rayleigh number scattering shipborne measurement spectral analysis transmittance uncertainty analysis water vapor 550 Witthuhn, Jonas Deneke, Hartwig Macke, Andreas Bernhard, Germar Algorithms and uncertainties for the determination of multispectral irradiance components and aerosol optical depth from a shipborne rotating shadowband radiometer |
topic_facet |
aerosol property algorithm calibration confidence interval irradiance optical depth precipitable water radiometer Rayleigh number scattering shipborne measurement spectral analysis transmittance uncertainty analysis water vapor 550 |
description |
The 19-channel rotating shadowband radiometer GUVis-3511 built by Biospherical Instruments provides automated shipborne measurements of the direct, diffuse and global spectral irradiance components without a requirement for platform stabilization. Several direct sun products, including spectral direct beam transmittance, aerosol optical depth, Ångström exponent and precipitable water, can be derived from these observations. The individual steps of the data analysis are described, and the different sources of uncertainty are discussed. The total uncertainty of the observed direct beam transmittances is estimated to be about 4% for most channels within a 95% confidence interval for shipborne operation. The calibration is identified as the dominating contribution to the total uncertainty. A comparison of direct beam transmittance with those obtained from a Cimel sunphotometer at a land site and a manually operated Microtops II sunphotometer on a ship is presented. Measurements deviate by less than 3 and 4% on land and on ship, respectively, for most channels and in agreement with our previous uncertainty estimate. These numbers demonstrate that the instrument is well suited for shipborne operation, and the applied methods for motion correction work accurately. Based on spectral direct beam transmittance, aerosol optical depth can be retrieved with an uncertainty of 0.02 for all channels within a 95% confidence interval. The different methods to account for Rayleigh scattering and gas absorption in our scheme and in the Aerosol Robotic Network processing for Cimel sunphotometers lead to minor deviations. Relying on the cross calibration of the 940 nm water vapor channel with the Cimel sunphotometer, the column amount of precipitable water can be estimated with an uncertainty of ±0.034 cm. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Witthuhn, Jonas Deneke, Hartwig Macke, Andreas Bernhard, Germar |
author_facet |
Witthuhn, Jonas Deneke, Hartwig Macke, Andreas Bernhard, Germar |
author_sort |
Witthuhn, Jonas |
title |
Algorithms and uncertainties for the determination of multispectral irradiance components and aerosol optical depth from a shipborne rotating shadowband radiometer |
title_short |
Algorithms and uncertainties for the determination of multispectral irradiance components and aerosol optical depth from a shipborne rotating shadowband radiometer |
title_full |
Algorithms and uncertainties for the determination of multispectral irradiance components and aerosol optical depth from a shipborne rotating shadowband radiometer |
title_fullStr |
Algorithms and uncertainties for the determination of multispectral irradiance components and aerosol optical depth from a shipborne rotating shadowband radiometer |
title_full_unstemmed |
Algorithms and uncertainties for the determination of multispectral irradiance components and aerosol optical depth from a shipborne rotating shadowband radiometer |
title_sort |
algorithms and uncertainties for the determination of multispectral irradiance components and aerosol optical depth from a shipborne rotating shadowband radiometer |
publisher |
Katlenburg-Lindau : Copernicus |
publishDate |
2017 |
url |
https://oa.tib.eu/renate/handle/123456789/11530 https://doi.org/10.34657/10564 |
genre |
Aerosol Robotic Network |
genre_facet |
Aerosol Robotic Network |
op_source |
Atmospheric measurement techniques : AMT 10 (2017), Nr. 2 |
op_rights |
CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0 |
op_doi |
https://doi.org/10.34657/10564 |
_version_ |
1768374897076076544 |