Depolarization calibration and measurements using the CANDAC Rayleigh–Mie–Raman lidar at Eureka, Canada
The Canadian Network for the Detection of Atmospheric Change (CANDAC) Rayleigh–Mie–Raman lidar (CRL) at Eureka, Nunavut, has measured tropospheric clouds, aerosols, and water vapour since 2007. In remote and meteorologically significant locations, such as the Canadian High Arctic, the ability to add...
Published in: | Atmospheric Measurement Techniques |
---|---|
Main Authors: | , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2017
|
Subjects: | |
Online Access: | https://doi.org/10.5194/amt-10-4253-2017 https://doaj.org/article/2de00d96e817422bb522e771428c324e |
id |
ftdoajarticles:oai:doaj.org/article:2de00d96e817422bb522e771428c324e |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:2de00d96e817422bb522e771428c324e 2023-05-15T14:59:13+02:00 Depolarization calibration and measurements using the CANDAC Rayleigh–Mie–Raman lidar at Eureka, Canada E. M. McCullough R. J. Sica J. R. Drummond G. Nott C. Perro C. P. Thackray J. Hopper J. Doyle T. J. Duck K. A. Walker 2017-11-01T00:00:00Z https://doi.org/10.5194/amt-10-4253-2017 https://doaj.org/article/2de00d96e817422bb522e771428c324e EN eng Copernicus Publications https://www.atmos-meas-tech.net/10/4253/2017/amt-10-4253-2017.pdf https://doaj.org/toc/1867-1381 https://doaj.org/toc/1867-8548 doi:10.5194/amt-10-4253-2017 1867-1381 1867-8548 https://doaj.org/article/2de00d96e817422bb522e771428c324e Atmospheric Measurement Techniques, Vol 10, Pp 4253-4277 (2017) Environmental engineering TA170-171 Earthwork. Foundations TA715-787 article 2017 ftdoajarticles https://doi.org/10.5194/amt-10-4253-2017 2022-12-31T07:10:35Z The Canadian Network for the Detection of Atmospheric Change (CANDAC) Rayleigh–Mie–Raman lidar (CRL) at Eureka, Nunavut, has measured tropospheric clouds, aerosols, and water vapour since 2007. In remote and meteorologically significant locations, such as the Canadian High Arctic, the ability to add new measurement capability to an existing well-tested facility is extremely valuable. In 2010, linear depolarization 532 nm measurement hardware was installed in the lidar's receiver. To minimize disruption in the existing lidar channels and to preserve their existing characterization so far as is possible, the depolarization hardware was placed near the end of the receiver cascade. The upstream optics already in place were not optimized for preserving the polarization of received light. Calibrations and Mueller matrix calculations are used to determine and mitigate the contribution of these upstream optics on the depolarization measurements. The results show that with appropriate calibration, indications of cloud particle phase (ice vs. water) through the use of the depolarization parameter are now possible to a precision of ±0.05 absolute uncertainty ( ≤ 10 % relative uncertainty) within clouds at time and altitude resolutions of 5 min and 37.5 m respectively, with higher precision and higher resolution possible in select cases. The uncertainty is somewhat larger outside of clouds at the same altitude, typically with absolute uncertainty ≤ 0.1. Monitoring changes in Arctic cloud composition, including particle phase, is essential for an improved understanding of the changing climate locally and globally. Article in Journal/Newspaper Arctic Eureka Nunavut Directory of Open Access Journals: DOAJ Articles Arctic Nunavut Canada Eureka ENVELOPE(-85.940,-85.940,79.990,79.990) Mueller ENVELOPE(55.533,55.533,-66.917,-66.917) Atmospheric Measurement Techniques 10 11 4253 4277 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 |
spellingShingle |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 E. M. McCullough R. J. Sica J. R. Drummond G. Nott C. Perro C. P. Thackray J. Hopper J. Doyle T. J. Duck K. A. Walker Depolarization calibration and measurements using the CANDAC Rayleigh–Mie–Raman lidar at Eureka, Canada |
topic_facet |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 |
description |
The Canadian Network for the Detection of Atmospheric Change (CANDAC) Rayleigh–Mie–Raman lidar (CRL) at Eureka, Nunavut, has measured tropospheric clouds, aerosols, and water vapour since 2007. In remote and meteorologically significant locations, such as the Canadian High Arctic, the ability to add new measurement capability to an existing well-tested facility is extremely valuable. In 2010, linear depolarization 532 nm measurement hardware was installed in the lidar's receiver. To minimize disruption in the existing lidar channels and to preserve their existing characterization so far as is possible, the depolarization hardware was placed near the end of the receiver cascade. The upstream optics already in place were not optimized for preserving the polarization of received light. Calibrations and Mueller matrix calculations are used to determine and mitigate the contribution of these upstream optics on the depolarization measurements. The results show that with appropriate calibration, indications of cloud particle phase (ice vs. water) through the use of the depolarization parameter are now possible to a precision of ±0.05 absolute uncertainty ( ≤ 10 % relative uncertainty) within clouds at time and altitude resolutions of 5 min and 37.5 m respectively, with higher precision and higher resolution possible in select cases. The uncertainty is somewhat larger outside of clouds at the same altitude, typically with absolute uncertainty ≤ 0.1. Monitoring changes in Arctic cloud composition, including particle phase, is essential for an improved understanding of the changing climate locally and globally. |
format |
Article in Journal/Newspaper |
author |
E. M. McCullough R. J. Sica J. R. Drummond G. Nott C. Perro C. P. Thackray J. Hopper J. Doyle T. J. Duck K. A. Walker |
author_facet |
E. M. McCullough R. J. Sica J. R. Drummond G. Nott C. Perro C. P. Thackray J. Hopper J. Doyle T. J. Duck K. A. Walker |
author_sort |
E. M. McCullough |
title |
Depolarization calibration and measurements using the CANDAC Rayleigh–Mie–Raman lidar at Eureka, Canada |
title_short |
Depolarization calibration and measurements using the CANDAC Rayleigh–Mie–Raman lidar at Eureka, Canada |
title_full |
Depolarization calibration and measurements using the CANDAC Rayleigh–Mie–Raman lidar at Eureka, Canada |
title_fullStr |
Depolarization calibration and measurements using the CANDAC Rayleigh–Mie–Raman lidar at Eureka, Canada |
title_full_unstemmed |
Depolarization calibration and measurements using the CANDAC Rayleigh–Mie–Raman lidar at Eureka, Canada |
title_sort |
depolarization calibration and measurements using the candac rayleigh–mie–raman lidar at eureka, canada |
publisher |
Copernicus Publications |
publishDate |
2017 |
url |
https://doi.org/10.5194/amt-10-4253-2017 https://doaj.org/article/2de00d96e817422bb522e771428c324e |
long_lat |
ENVELOPE(-85.940,-85.940,79.990,79.990) ENVELOPE(55.533,55.533,-66.917,-66.917) |
geographic |
Arctic Nunavut Canada Eureka Mueller |
geographic_facet |
Arctic Nunavut Canada Eureka Mueller |
genre |
Arctic Eureka Nunavut |
genre_facet |
Arctic Eureka Nunavut |
op_source |
Atmospheric Measurement Techniques, Vol 10, Pp 4253-4277 (2017) |
op_relation |
https://www.atmos-meas-tech.net/10/4253/2017/amt-10-4253-2017.pdf https://doaj.org/toc/1867-1381 https://doaj.org/toc/1867-8548 doi:10.5194/amt-10-4253-2017 1867-1381 1867-8548 https://doaj.org/article/2de00d96e817422bb522e771428c324e |
op_doi |
https://doi.org/10.5194/amt-10-4253-2017 |
container_title |
Atmospheric Measurement Techniques |
container_volume |
10 |
container_issue |
11 |
container_start_page |
4253 |
op_container_end_page |
4277 |
_version_ |
1766331342527660032 |