Formation of large NAT particles and denitrification in polar stratosphere: possible role of cosmic rays and effect of solar activity
International audience The formation of large nitric acid trihydrate (NAT) particles has important implications for denitrification and ozone depletion. Existing theories have difficulty in explaining the formation of large NAT particles at temperatures above the ice frost point, which has been obse...
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ftinsu:oai:HAL:hal-00295552v1 2023-11-12T04:13:43+01:00 Formation of large NAT particles and denitrification in polar stratosphere: possible role of cosmic rays and effect of solar activity Yu, F. Atmospheric Sciences Research Center (ASRC) University at Albany SUNY State University of New York (SUNY)-State University of New York (SUNY) 2004-11-23 https://hal.science/hal-00295552 https://hal.science/hal-00295552/document https://hal.science/hal-00295552/file/acp-4-2273-2004.pdf en eng HAL CCSD European Geosciences Union hal-00295552 https://hal.science/hal-00295552 https://hal.science/hal-00295552/document https://hal.science/hal-00295552/file/acp-4-2273-2004.pdf info:eu-repo/semantics/OpenAccess ISSN: 1680-7316 EISSN: 1680-7324 Atmospheric Chemistry and Physics https://hal.science/hal-00295552 Atmospheric Chemistry and Physics, 2004, 4 (9/10), pp.2273-2283 [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere info:eu-repo/semantics/article Journal articles 2004 ftinsu 2023-10-25T16:30:05Z International audience The formation of large nitric acid trihydrate (NAT) particles has important implications for denitrification and ozone depletion. Existing theories have difficulty in explaining the formation of large NAT particles at temperatures above the ice frost point, which has been observed recently over wide Arctic regions. Our analyses reveal that high-energy comic ray particles might induce the freezing of supercooled HNO 3 -H 2 O-H 2 SO 4 droplets when they penetrate these thermodynamically unstable droplets. The cosmic ray-induced freezing (CRIF) appears to be consistent with the observed, highly selective formation of NAT particles. We suggest a possible physical process behind the CRIF mechanism: the reorientation of polar solution molecules into the crystalline configuration in the strong electrical fields of moving secondary ions generated by passing cosmic rays. A simple formula connecting the CRIF rate to cosmic ray flux is derived with an undefined parameter constrained by observed NAT formation rates. Our simulations indicate that strong solar proton events (SPEs) may significantly enhance the formation of large NAT particles and denitrification. The CRIF mechanism offers a possible explanation for the observed high correlations between the thin nitrate-rich layers in polar ice cores and major SPEs, and the observed enhancement in the aerosol backscattering ratio at PSC layers shortly after an SPE and the significant precipitation velocity of the enhanced PSC layers. The key uncertainty in the CRIF mechanism is the probability ( P ) of freezing when a CR particle hits a thermodynamically, unstable STS droplet. Further studies are needed to either confirm or reject the CRIF hypothesis. Article in Journal/Newspaper Arctic Institut national des sciences de l'Univers: HAL-INSU Arctic |
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Institut national des sciences de l'Univers: HAL-INSU |
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language |
English |
topic |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
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[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere Yu, F. Formation of large NAT particles and denitrification in polar stratosphere: possible role of cosmic rays and effect of solar activity |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
description |
International audience The formation of large nitric acid trihydrate (NAT) particles has important implications for denitrification and ozone depletion. Existing theories have difficulty in explaining the formation of large NAT particles at temperatures above the ice frost point, which has been observed recently over wide Arctic regions. Our analyses reveal that high-energy comic ray particles might induce the freezing of supercooled HNO 3 -H 2 O-H 2 SO 4 droplets when they penetrate these thermodynamically unstable droplets. The cosmic ray-induced freezing (CRIF) appears to be consistent with the observed, highly selective formation of NAT particles. We suggest a possible physical process behind the CRIF mechanism: the reorientation of polar solution molecules into the crystalline configuration in the strong electrical fields of moving secondary ions generated by passing cosmic rays. A simple formula connecting the CRIF rate to cosmic ray flux is derived with an undefined parameter constrained by observed NAT formation rates. Our simulations indicate that strong solar proton events (SPEs) may significantly enhance the formation of large NAT particles and denitrification. The CRIF mechanism offers a possible explanation for the observed high correlations between the thin nitrate-rich layers in polar ice cores and major SPEs, and the observed enhancement in the aerosol backscattering ratio at PSC layers shortly after an SPE and the significant precipitation velocity of the enhanced PSC layers. The key uncertainty in the CRIF mechanism is the probability ( P ) of freezing when a CR particle hits a thermodynamically, unstable STS droplet. Further studies are needed to either confirm or reject the CRIF hypothesis. |
author2 |
Atmospheric Sciences Research Center (ASRC) University at Albany SUNY State University of New York (SUNY)-State University of New York (SUNY) |
format |
Article in Journal/Newspaper |
author |
Yu, F. |
author_facet |
Yu, F. |
author_sort |
Yu, F. |
title |
Formation of large NAT particles and denitrification in polar stratosphere: possible role of cosmic rays and effect of solar activity |
title_short |
Formation of large NAT particles and denitrification in polar stratosphere: possible role of cosmic rays and effect of solar activity |
title_full |
Formation of large NAT particles and denitrification in polar stratosphere: possible role of cosmic rays and effect of solar activity |
title_fullStr |
Formation of large NAT particles and denitrification in polar stratosphere: possible role of cosmic rays and effect of solar activity |
title_full_unstemmed |
Formation of large NAT particles and denitrification in polar stratosphere: possible role of cosmic rays and effect of solar activity |
title_sort |
formation of large nat particles and denitrification in polar stratosphere: possible role of cosmic rays and effect of solar activity |
publisher |
HAL CCSD |
publishDate |
2004 |
url |
https://hal.science/hal-00295552 https://hal.science/hal-00295552/document https://hal.science/hal-00295552/file/acp-4-2273-2004.pdf |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
ISSN: 1680-7316 EISSN: 1680-7324 Atmospheric Chemistry and Physics https://hal.science/hal-00295552 Atmospheric Chemistry and Physics, 2004, 4 (9/10), pp.2273-2283 |
op_relation |
hal-00295552 https://hal.science/hal-00295552 https://hal.science/hal-00295552/document https://hal.science/hal-00295552/file/acp-4-2273-2004.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1782331580319006720 |