Highly supercooled riming and unusual triple-frequency radar signatures over McMurdo Station, Antarctica
Riming of ice crystals by supercooled water droplets is an efficient ice growth process, but its basic properties are still poorly known. While it has been shown to contribute significantly to surface precipitation at mid-latitudes, little is known about its occurrence at high latitudes. In Antarcti...
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Online Access: | http://www.osti.gov/servlets/purl/1891012 https://www.osti.gov/biblio/1891012 https://doi.org/10.5194/acp-22-12467-2022 |
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ftosti:oai:osti.gov:1891012 2023-07-30T03:58:57+02:00 Highly supercooled riming and unusual triple-frequency radar signatures over McMurdo Station, Antarctica Tridon, Frederic Silber, Israel Battaglia, Alessandro Kneifel, Stefan Fridlind, Ann Kalogeras, Petros Dhillon, Ranvir 2023-02-23 application/pdf http://www.osti.gov/servlets/purl/1891012 https://www.osti.gov/biblio/1891012 https://doi.org/10.5194/acp-22-12467-2022 unknown http://www.osti.gov/servlets/purl/1891012 https://www.osti.gov/biblio/1891012 https://doi.org/10.5194/acp-22-12467-2022 doi:10.5194/acp-22-12467-2022 54 ENVIRONMENTAL SCIENCES 2023 ftosti https://doi.org/10.5194/acp-22-12467-2022 2023-07-11T10:15:21Z Riming of ice crystals by supercooled water droplets is an efficient ice growth process, but its basic properties are still poorly known. While it has been shown to contribute significantly to surface precipitation at mid-latitudes, little is known about its occurrence at high latitudes. In Antarctica, two competing effects can influence the occurrence of riming: (i) the scarcity of supercooled liquid water clouds due to the extremely low tropospheric temperatures and (ii) the low aerosol concentration, which may lead to the formation of fewer and larger supercooled drops potentially resulting in an enhanced riming efficiency. In this work, by exploiting the deployment of an unprecedented number of multiwavelength remote sensing systems (including triple-frequency radar measurements) in West Antarctica, during the Atmospheric Radiation Measurements West Antarctic Radiation Experiment (AWARE) field campaign, we evaluate the riming incidence at McMurdo Station and find that riming occurs at much lower temperatures when compared to previous results in the mid-latitudes. This suggests the possible occurrence of a common atmospheric state over Antarctica that includes a rather stable atmosphere inhibiting turbulent mixing, and a high riming efficiency driven by large cloud droplets. We then focus on a peculiar case study featuring a persistent layer with a particularly pronounced riming signature in triple-frequency radar data but only a relatively modest amount of supercooled liquid water. In-depth analysis of the radar observations suggests that such signatures can only be explained by the combined effects of moderately rimed aggregates or similarly shaped florid polycrystals and a narrow particle size distribution (PSD). Simulations of this case study performed with a one-dimensional bin model indicate that similar triple-frequency radar observations can be reproduced when narrow PSDs are simulated. Such narrow PSDs can in turn be explained by two key factors: (i) the presence of a shallow homogeneous droplet or ... Other/Unknown Material Antarc* Antarctic Antarctica West Antarctica SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Antarctic West Antarctica McMurdo Station ENVELOPE(166.667,166.667,-77.850,-77.850) Atmospheric Chemistry and Physics 22 18 12467 12491 |
institution |
Open Polar |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
op_collection_id |
ftosti |
language |
unknown |
topic |
54 ENVIRONMENTAL SCIENCES |
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54 ENVIRONMENTAL SCIENCES Tridon, Frederic Silber, Israel Battaglia, Alessandro Kneifel, Stefan Fridlind, Ann Kalogeras, Petros Dhillon, Ranvir Highly supercooled riming and unusual triple-frequency radar signatures over McMurdo Station, Antarctica |
topic_facet |
54 ENVIRONMENTAL SCIENCES |
description |
Riming of ice crystals by supercooled water droplets is an efficient ice growth process, but its basic properties are still poorly known. While it has been shown to contribute significantly to surface precipitation at mid-latitudes, little is known about its occurrence at high latitudes. In Antarctica, two competing effects can influence the occurrence of riming: (i) the scarcity of supercooled liquid water clouds due to the extremely low tropospheric temperatures and (ii) the low aerosol concentration, which may lead to the formation of fewer and larger supercooled drops potentially resulting in an enhanced riming efficiency. In this work, by exploiting the deployment of an unprecedented number of multiwavelength remote sensing systems (including triple-frequency radar measurements) in West Antarctica, during the Atmospheric Radiation Measurements West Antarctic Radiation Experiment (AWARE) field campaign, we evaluate the riming incidence at McMurdo Station and find that riming occurs at much lower temperatures when compared to previous results in the mid-latitudes. This suggests the possible occurrence of a common atmospheric state over Antarctica that includes a rather stable atmosphere inhibiting turbulent mixing, and a high riming efficiency driven by large cloud droplets. We then focus on a peculiar case study featuring a persistent layer with a particularly pronounced riming signature in triple-frequency radar data but only a relatively modest amount of supercooled liquid water. In-depth analysis of the radar observations suggests that such signatures can only be explained by the combined effects of moderately rimed aggregates or similarly shaped florid polycrystals and a narrow particle size distribution (PSD). Simulations of this case study performed with a one-dimensional bin model indicate that similar triple-frequency radar observations can be reproduced when narrow PSDs are simulated. Such narrow PSDs can in turn be explained by two key factors: (i) the presence of a shallow homogeneous droplet or ... |
author |
Tridon, Frederic Silber, Israel Battaglia, Alessandro Kneifel, Stefan Fridlind, Ann Kalogeras, Petros Dhillon, Ranvir |
author_facet |
Tridon, Frederic Silber, Israel Battaglia, Alessandro Kneifel, Stefan Fridlind, Ann Kalogeras, Petros Dhillon, Ranvir |
author_sort |
Tridon, Frederic |
title |
Highly supercooled riming and unusual triple-frequency radar signatures over McMurdo Station, Antarctica |
title_short |
Highly supercooled riming and unusual triple-frequency radar signatures over McMurdo Station, Antarctica |
title_full |
Highly supercooled riming and unusual triple-frequency radar signatures over McMurdo Station, Antarctica |
title_fullStr |
Highly supercooled riming and unusual triple-frequency radar signatures over McMurdo Station, Antarctica |
title_full_unstemmed |
Highly supercooled riming and unusual triple-frequency radar signatures over McMurdo Station, Antarctica |
title_sort |
highly supercooled riming and unusual triple-frequency radar signatures over mcmurdo station, antarctica |
publishDate |
2023 |
url |
http://www.osti.gov/servlets/purl/1891012 https://www.osti.gov/biblio/1891012 https://doi.org/10.5194/acp-22-12467-2022 |
long_lat |
ENVELOPE(166.667,166.667,-77.850,-77.850) |
geographic |
Antarctic West Antarctica McMurdo Station |
geographic_facet |
Antarctic West Antarctica McMurdo Station |
genre |
Antarc* Antarctic Antarctica West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica West Antarctica |
op_relation |
http://www.osti.gov/servlets/purl/1891012 https://www.osti.gov/biblio/1891012 https://doi.org/10.5194/acp-22-12467-2022 doi:10.5194/acp-22-12467-2022 |
op_doi |
https://doi.org/10.5194/acp-22-12467-2022 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
22 |
container_issue |
18 |
container_start_page |
12467 |
op_container_end_page |
12491 |
_version_ |
1772809673268789248 |