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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ftcopernicus:oai:publications.copernicus.org:acp101509 2023-05-15T13:38:41+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 2022-09-23 application/pdf https://doi.org/10.5194/acp-22-12467-2022 https://acp.copernicus.org/articles/22/12467/2022/ eng eng doi:10.5194/acp-22-12467-2022 https://acp.copernicus.org/articles/22/12467/2022/ eISSN: 1680-7324 Text 2022 ftcopernicus https://doi.org/10.5194/acp-22-12467-2022 2022-09-26T16:22:41Z 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 ... Text Antarc* Antarctic Antarctica West Antarctica Copernicus Publications: E-Journals Antarctic McMurdo Station ENVELOPE(166.667,166.667,-77.850,-77.850) West Antarctica Atmospheric Chemistry and Physics 22 18 12467 12491 |
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Open Polar |
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Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
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 ... |
format |
Text |
author |
Tridon, Frederic Silber, Israel Battaglia, Alessandro Kneifel, Stefan Fridlind, Ann Kalogeras, Petros Dhillon, Ranvir |
spellingShingle |
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 |
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 |
2022 |
url |
https://doi.org/10.5194/acp-22-12467-2022 https://acp.copernicus.org/articles/22/12467/2022/ |
long_lat |
ENVELOPE(166.667,166.667,-77.850,-77.850) |
geographic |
Antarctic McMurdo Station West Antarctica |
geographic_facet |
Antarctic McMurdo Station West Antarctica |
genre |
Antarc* Antarctic Antarctica West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica West Antarctica |
op_source |
eISSN: 1680-7324 |
op_relation |
doi:10.5194/acp-22-12467-2022 https://acp.copernicus.org/articles/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 |
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1766109562345095168 |