Identification of snowfall microphysical processes from Eulerian vertical gradients of polarimetric radar variables
Polarimetric radar systems are commonly used to study the microphysics of precipitation. While they offer continuous measurements with a large spatial coverage, retrieving information about the microphysical processes that govern the evolution of snowfall from the polarimetric signal is challenging....
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ftdoajarticles:oai:doaj.org/article:7b6abbc1bd844ed08fbd10d0f987fe20 2023-05-15T14:03:49+02:00 Identification of snowfall microphysical processes from Eulerian vertical gradients of polarimetric radar variables N. Planat J. Gehring É. Vignon A. Berne 2021-06-01T00:00:00Z https://doi.org/10.5194/amt-14-4543-2021 https://doaj.org/article/7b6abbc1bd844ed08fbd10d0f987fe20 EN eng Copernicus Publications https://amt.copernicus.org/articles/14/4543/2021/amt-14-4543-2021.pdf https://doaj.org/toc/1867-1381 https://doaj.org/toc/1867-8548 doi:10.5194/amt-14-4543-2021 1867-1381 1867-8548 https://doaj.org/article/7b6abbc1bd844ed08fbd10d0f987fe20 Atmospheric Measurement Techniques, Vol 14, Pp 4543-4564 (2021) Environmental engineering TA170-171 Earthwork. Foundations TA715-787 article 2021 ftdoajarticles https://doi.org/10.5194/amt-14-4543-2021 2022-12-31T12:30:06Z Polarimetric radar systems are commonly used to study the microphysics of precipitation. While they offer continuous measurements with a large spatial coverage, retrieving information about the microphysical processes that govern the evolution of snowfall from the polarimetric signal is challenging. The present study develops a new method, called process identification based on vertical gradient signs (PIVSs), to spatially identify the occurrence of the main microphysical processes (aggregation and riming, crystal growth by vapor deposition and sublimation) in snowfall from dual-polarization Doppler radar scans. We first derive an analytical framework to assess in which meteorological conditions the local vertical gradients of radar variables reliably inform about microphysical processes. In such conditions, we then identify regions dominated by (i) vapor deposition, (ii) aggregation and riming and (iii) snowflake sublimation and possibly snowflake breakup, based on the sign of the local vertical gradients of the reflectivity Z H and the differential reflectivity Z DR . The method is then applied to data from two frontal snowfall events, namely one in coastal Adélie Land, Antarctica, and one in the Taebaek Mountains in South Korea. The validity of the method is assessed by comparing its outcome with snowflake observations, using a multi-angle snowflake camera, and with the output of a hydrometeor classification, based on polarimetric radar signal. The application of the method further makes it possible to better characterize and understand how snowfall forms, grows and decays in two different geographical and meteorological contexts. In particular, we are able to automatically derive and discuss the altitude and thickness of the layers where each process prevails for both case studies. We infer some microphysical characteristics in terms of radar variables from statistical analysis of the method output (e.g., Z H and Z DR distribution for each process). We, finally, highlight the potential for extensive ... Article in Journal/Newspaper Antarc* Antarctica Directory of Open Access Journals: DOAJ Articles Atmospheric Measurement Techniques 14 6 4543 4564 |
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Directory of Open Access Journals: DOAJ Articles |
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Environmental engineering TA170-171 Earthwork. Foundations TA715-787 |
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Environmental engineering TA170-171 Earthwork. Foundations TA715-787 N. Planat J. Gehring É. Vignon A. Berne Identification of snowfall microphysical processes from Eulerian vertical gradients of polarimetric radar variables |
topic_facet |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 |
description |
Polarimetric radar systems are commonly used to study the microphysics of precipitation. While they offer continuous measurements with a large spatial coverage, retrieving information about the microphysical processes that govern the evolution of snowfall from the polarimetric signal is challenging. The present study develops a new method, called process identification based on vertical gradient signs (PIVSs), to spatially identify the occurrence of the main microphysical processes (aggregation and riming, crystal growth by vapor deposition and sublimation) in snowfall from dual-polarization Doppler radar scans. We first derive an analytical framework to assess in which meteorological conditions the local vertical gradients of radar variables reliably inform about microphysical processes. In such conditions, we then identify regions dominated by (i) vapor deposition, (ii) aggregation and riming and (iii) snowflake sublimation and possibly snowflake breakup, based on the sign of the local vertical gradients of the reflectivity Z H and the differential reflectivity Z DR . The method is then applied to data from two frontal snowfall events, namely one in coastal Adélie Land, Antarctica, and one in the Taebaek Mountains in South Korea. The validity of the method is assessed by comparing its outcome with snowflake observations, using a multi-angle snowflake camera, and with the output of a hydrometeor classification, based on polarimetric radar signal. The application of the method further makes it possible to better characterize and understand how snowfall forms, grows and decays in two different geographical and meteorological contexts. In particular, we are able to automatically derive and discuss the altitude and thickness of the layers where each process prevails for both case studies. We infer some microphysical characteristics in terms of radar variables from statistical analysis of the method output (e.g., Z H and Z DR distribution for each process). We, finally, highlight the potential for extensive ... |
format |
Article in Journal/Newspaper |
author |
N. Planat J. Gehring É. Vignon A. Berne |
author_facet |
N. Planat J. Gehring É. Vignon A. Berne |
author_sort |
N. Planat |
title |
Identification of snowfall microphysical processes from Eulerian vertical gradients of polarimetric radar variables |
title_short |
Identification of snowfall microphysical processes from Eulerian vertical gradients of polarimetric radar variables |
title_full |
Identification of snowfall microphysical processes from Eulerian vertical gradients of polarimetric radar variables |
title_fullStr |
Identification of snowfall microphysical processes from Eulerian vertical gradients of polarimetric radar variables |
title_full_unstemmed |
Identification of snowfall microphysical processes from Eulerian vertical gradients of polarimetric radar variables |
title_sort |
identification of snowfall microphysical processes from eulerian vertical gradients of polarimetric radar variables |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/amt-14-4543-2021 https://doaj.org/article/7b6abbc1bd844ed08fbd10d0f987fe20 |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
Atmospheric Measurement Techniques, Vol 14, Pp 4543-4564 (2021) |
op_relation |
https://amt.copernicus.org/articles/14/4543/2021/amt-14-4543-2021.pdf https://doaj.org/toc/1867-1381 https://doaj.org/toc/1867-8548 doi:10.5194/amt-14-4543-2021 1867-1381 1867-8548 https://doaj.org/article/7b6abbc1bd844ed08fbd10d0f987fe20 |
op_doi |
https://doi.org/10.5194/amt-14-4543-2021 |
container_title |
Atmospheric Measurement Techniques |
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14 |
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6 |
container_start_page |
4543 |
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4564 |
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1766274674887491584 |