Aerosol-related effects on the occurrence of heterogeneous ice formation over Lauder, New Zealand/Aotearoa
The presented study investigates the efficiency of heterogeneous ice formation in natural clouds over Lauder, New Zealand / Aotearoa. Aerosol conditions in the middle troposphere above Lauder are subject to huge contrasts. Clean, pristine air masses from Antarctica and the Southern Ocean arrive unde...
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ftcopernicus:oai:publications.copernicus.org:egusphere114972 2024-09-15T17:48:36+00:00 Aerosol-related effects on the occurrence of heterogeneous ice formation over Lauder, New Zealand/Aotearoa Hofer, Julian Seifert, Patric Liley, J. Ben Radenz, Martin Uchino, Osamu Morino, Isamu Sakai, Tetsu Nagai, Tomohiro Ansmann, Albert 2024-01-29 application/pdf https://doi.org/10.5194/egusphere-2023-2173 https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2173/ eng eng doi:10.5194/egusphere-2023-2173 https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2173/ eISSN: Text 2024 ftcopernicus https://doi.org/10.5194/egusphere-2023-2173 2024-08-28T05:24:15Z The presented study investigates the efficiency of heterogeneous ice formation in natural clouds over Lauder, New Zealand / Aotearoa. Aerosol conditions in the middle troposphere above Lauder are subject to huge contrasts. Clean, pristine air masses from Antarctica and the Southern Ocean arrive under southerly flow conditions, while high aerosol loads can occur when air masses are advected from nearby Australia. This study assesses how these contrasts in aerosol load affect the ice formation efficiency in stratiform midlevel clouds in the heterogeneous freezing range ( − 40 to 0 ∘ C ). For this purpose, an 11-year dataset was analyzed from a dual-wavelength polarization lidar system operated by National Institute of Water and Atmospheric Research (NIWA), Taihoro Nukurangi, at Lauder in collaboration with the National Institute for Environmental Studies in Japan and the Meteorological Research Institute of the Japan Meteorological Agency. These data were used to investigate the efficiency of heterogeneous ice formation in clouds over the site as a function of cloud-top temperature as in previous studies at other locations. The Lauder cloud dataset was put into context with lidar studies from contrasting regions such as Germany and southern Chile. The ice formation efficiency found at Lauder is lower than in polluted midlatitudes (i.e., Germany) but higher than, for example, in southern Chile. Both Lauder and southern Chile are subject to generally low free-tropospheric aerosol loads, which suggests that the low ice formation efficiency at these two sites is related to low ice-nucleating-particle (INP) concentrations. However, Lauder sees episodes of continental aerosol, more than southern Chile does, which seems to lead to the moderately increased ice formation efficiency. Trajectory-based tools and aerosol model reanalyses are used to relate this cloud dataset to the aerosol load and the air mass sources. Both analyses point clearly to higher ice formation efficiency for clouds which are more strongly influenced ... Text Antarc* Antarctica Southern Ocean Copernicus Publications: E-Journals |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
The presented study investigates the efficiency of heterogeneous ice formation in natural clouds over Lauder, New Zealand / Aotearoa. Aerosol conditions in the middle troposphere above Lauder are subject to huge contrasts. Clean, pristine air masses from Antarctica and the Southern Ocean arrive under southerly flow conditions, while high aerosol loads can occur when air masses are advected from nearby Australia. This study assesses how these contrasts in aerosol load affect the ice formation efficiency in stratiform midlevel clouds in the heterogeneous freezing range ( − 40 to 0 ∘ C ). For this purpose, an 11-year dataset was analyzed from a dual-wavelength polarization lidar system operated by National Institute of Water and Atmospheric Research (NIWA), Taihoro Nukurangi, at Lauder in collaboration with the National Institute for Environmental Studies in Japan and the Meteorological Research Institute of the Japan Meteorological Agency. These data were used to investigate the efficiency of heterogeneous ice formation in clouds over the site as a function of cloud-top temperature as in previous studies at other locations. The Lauder cloud dataset was put into context with lidar studies from contrasting regions such as Germany and southern Chile. The ice formation efficiency found at Lauder is lower than in polluted midlatitudes (i.e., Germany) but higher than, for example, in southern Chile. Both Lauder and southern Chile are subject to generally low free-tropospheric aerosol loads, which suggests that the low ice formation efficiency at these two sites is related to low ice-nucleating-particle (INP) concentrations. However, Lauder sees episodes of continental aerosol, more than southern Chile does, which seems to lead to the moderately increased ice formation efficiency. Trajectory-based tools and aerosol model reanalyses are used to relate this cloud dataset to the aerosol load and the air mass sources. Both analyses point clearly to higher ice formation efficiency for clouds which are more strongly influenced ... |
format |
Text |
author |
Hofer, Julian Seifert, Patric Liley, J. Ben Radenz, Martin Uchino, Osamu Morino, Isamu Sakai, Tetsu Nagai, Tomohiro Ansmann, Albert |
spellingShingle |
Hofer, Julian Seifert, Patric Liley, J. Ben Radenz, Martin Uchino, Osamu Morino, Isamu Sakai, Tetsu Nagai, Tomohiro Ansmann, Albert Aerosol-related effects on the occurrence of heterogeneous ice formation over Lauder, New Zealand/Aotearoa |
author_facet |
Hofer, Julian Seifert, Patric Liley, J. Ben Radenz, Martin Uchino, Osamu Morino, Isamu Sakai, Tetsu Nagai, Tomohiro Ansmann, Albert |
author_sort |
Hofer, Julian |
title |
Aerosol-related effects on the occurrence of heterogeneous ice formation over Lauder, New Zealand/Aotearoa |
title_short |
Aerosol-related effects on the occurrence of heterogeneous ice formation over Lauder, New Zealand/Aotearoa |
title_full |
Aerosol-related effects on the occurrence of heterogeneous ice formation over Lauder, New Zealand/Aotearoa |
title_fullStr |
Aerosol-related effects on the occurrence of heterogeneous ice formation over Lauder, New Zealand/Aotearoa |
title_full_unstemmed |
Aerosol-related effects on the occurrence of heterogeneous ice formation over Lauder, New Zealand/Aotearoa |
title_sort |
aerosol-related effects on the occurrence of heterogeneous ice formation over lauder, new zealand/aotearoa |
publishDate |
2024 |
url |
https://doi.org/10.5194/egusphere-2023-2173 https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2173/ |
genre |
Antarc* Antarctica Southern Ocean |
genre_facet |
Antarc* Antarctica Southern Ocean |
op_source |
eISSN: |
op_relation |
doi:10.5194/egusphere-2023-2173 https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2173/ |
op_doi |
https://doi.org/10.5194/egusphere-2023-2173 |
_version_ |
1810290036451573760 |