Horizontal geometry of trade wind cumuli - aircraft observations from a shortwave infrared imager versus a radar profiler
This study elaborates on how aircraft-based horizontal geometries of trade wind cumulus clouds differ whether a one-dimensional (1D) profiler or a two-dimensional (2D) imager is used. While nadir profiling devices are limited to a 1D realization of the cloud transect size, with limited representativ...
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ftpubman:oai:pure.mpg.de:item_3391018 2024-09-09T20:14:34+00:00 Horizontal geometry of trade wind cumuli - aircraft observations from a shortwave infrared imager versus a radar profiler Dorff, H. Konow, H. Ament, F. 2022-06-16 application/pdf http://hdl.handle.net/21.11116/0000-000A-ABC7-5 http://hdl.handle.net/21.11116/0000-000A-ABC9-3 eng eng info:eu-repo/semantics/altIdentifier/doi/10.5194/amt-15-3641-2022 http://hdl.handle.net/21.11116/0000-000A-ABC7-5 http://hdl.handle.net/21.11116/0000-000A-ABC9-3 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Atmospheric Measurement Techniques info:eu-repo/semantics/article 2022 ftpubman https://doi.org/10.5194/amt-15-3641-2022 2024-06-18T14:12:31Z This study elaborates on how aircraft-based horizontal geometries of trade wind cumulus clouds differ whether a one-dimensional (1D) profiler or a two-dimensional (2D) imager is used. While nadir profiling devices are limited to a 1D realization of the cloud transect size, with limited representativeness of horizontal cloud extension, 2D imagers enhance our perspectives by mapping the horizontal cloud field. Both require high resolutions to detect the lower end of the cloud size spectrum. In this regard, the payload aboard the HALO (High Altitude and LOng Range Research Aircraft) achieves a comparison and also a synergy of both measurement systems. Using the NARVAL II (Next-Generation Aircraft Remote-Sensing for Validation Studies) campaign, we combine HALO observations from a 35.2 GHz cloud and precipitation radar (1D) and from the hyperspectral 2D imager specMACS (Munich Aerosol Cloud Scanner), with a 30 times higher along-track resolution, and compare their cloud masks. We examine cloud size distributions in terms of sensitivity to sample size, resolution and the considered field of view (2D or 1D). This specifies impacts on horizontal cloud sizes derived from the across-track perspective of the high-resolution imager in comparison to the radar curtain. We assess whether and how the trade wind field amplifies uncertainties in cloud geometry observations along 1D transects through directional cloud elongation. Our findings reveal that each additional dimension, no matter of the device, causes a significant increase in observed clouds. The across-track field yields the highest increase in the cloud sample. The radar encounters difficulties in characterizing the trade wind cumuli size distribution. More than 60 % of clouds are subgrid scale for the radar. The radar has issues in the representation of clouds shorter than 200 m, as they are either unresolved or are incorrectly displayed as single grid points. Very shallow clouds can also remain unresolved due to too low radar sensitivity. Both facts deteriorate ... Article in Journal/Newspaper narval narval Max Planck Society: MPG.PuRe Atmospheric Measurement Techniques 15 12 3641 3661 |
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Open Polar |
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Max Planck Society: MPG.PuRe |
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ftpubman |
language |
English |
description |
This study elaborates on how aircraft-based horizontal geometries of trade wind cumulus clouds differ whether a one-dimensional (1D) profiler or a two-dimensional (2D) imager is used. While nadir profiling devices are limited to a 1D realization of the cloud transect size, with limited representativeness of horizontal cloud extension, 2D imagers enhance our perspectives by mapping the horizontal cloud field. Both require high resolutions to detect the lower end of the cloud size spectrum. In this regard, the payload aboard the HALO (High Altitude and LOng Range Research Aircraft) achieves a comparison and also a synergy of both measurement systems. Using the NARVAL II (Next-Generation Aircraft Remote-Sensing for Validation Studies) campaign, we combine HALO observations from a 35.2 GHz cloud and precipitation radar (1D) and from the hyperspectral 2D imager specMACS (Munich Aerosol Cloud Scanner), with a 30 times higher along-track resolution, and compare their cloud masks. We examine cloud size distributions in terms of sensitivity to sample size, resolution and the considered field of view (2D or 1D). This specifies impacts on horizontal cloud sizes derived from the across-track perspective of the high-resolution imager in comparison to the radar curtain. We assess whether and how the trade wind field amplifies uncertainties in cloud geometry observations along 1D transects through directional cloud elongation. Our findings reveal that each additional dimension, no matter of the device, causes a significant increase in observed clouds. The across-track field yields the highest increase in the cloud sample. The radar encounters difficulties in characterizing the trade wind cumuli size distribution. More than 60 % of clouds are subgrid scale for the radar. The radar has issues in the representation of clouds shorter than 200 m, as they are either unresolved or are incorrectly displayed as single grid points. Very shallow clouds can also remain unresolved due to too low radar sensitivity. Both facts deteriorate ... |
format |
Article in Journal/Newspaper |
author |
Dorff, H. Konow, H. Ament, F. |
spellingShingle |
Dorff, H. Konow, H. Ament, F. Horizontal geometry of trade wind cumuli - aircraft observations from a shortwave infrared imager versus a radar profiler |
author_facet |
Dorff, H. Konow, H. Ament, F. |
author_sort |
Dorff, H. |
title |
Horizontal geometry of trade wind cumuli - aircraft observations from a shortwave infrared imager versus a radar profiler |
title_short |
Horizontal geometry of trade wind cumuli - aircraft observations from a shortwave infrared imager versus a radar profiler |
title_full |
Horizontal geometry of trade wind cumuli - aircraft observations from a shortwave infrared imager versus a radar profiler |
title_fullStr |
Horizontal geometry of trade wind cumuli - aircraft observations from a shortwave infrared imager versus a radar profiler |
title_full_unstemmed |
Horizontal geometry of trade wind cumuli - aircraft observations from a shortwave infrared imager versus a radar profiler |
title_sort |
horizontal geometry of trade wind cumuli - aircraft observations from a shortwave infrared imager versus a radar profiler |
publishDate |
2022 |
url |
http://hdl.handle.net/21.11116/0000-000A-ABC7-5 http://hdl.handle.net/21.11116/0000-000A-ABC9-3 |
genre |
narval narval |
genre_facet |
narval narval |
op_source |
Atmospheric Measurement Techniques |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/amt-15-3641-2022 http://hdl.handle.net/21.11116/0000-000A-ABC7-5 http://hdl.handle.net/21.11116/0000-000A-ABC9-3 |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.5194/amt-15-3641-2022 |
container_title |
Atmospheric Measurement Techniques |
container_volume |
15 |
container_issue |
12 |
container_start_page |
3641 |
op_container_end_page |
3661 |
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1809816230989660160 |