Formation of large NAT particles and denitrification in polar stratosphere: possible role of cosmic rays and effect of solar activity
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...
Main Author: | |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2004
|
Subjects: | |
Online Access: | https://doaj.org/article/84d7cda9d0a7448cad877d31683d1866 |
id |
ftdoajarticles:oai:doaj.org/article:84d7cda9d0a7448cad877d31683d1866 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:84d7cda9d0a7448cad877d31683d1866 2023-05-15T15:12:15+02:00 Formation of large NAT particles and denitrification in polar stratosphere: possible role of cosmic rays and effect of solar activity F. Yu 2004-01-01T00:00:00Z https://doaj.org/article/84d7cda9d0a7448cad877d31683d1866 EN eng Copernicus Publications http://www.atmos-chem-phys.net/4/2273/2004/acp-4-2273-2004.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 1680-7316 1680-7324 https://doaj.org/article/84d7cda9d0a7448cad877d31683d1866 Atmospheric Chemistry and Physics, Vol 4, Iss 9/10, Pp 2273-2283 (2004) Physics QC1-999 Chemistry QD1-999 article 2004 ftdoajarticles 2022-12-30T23:59:51Z 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 Directory of Open Access Journals: DOAJ Articles Arctic |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Physics QC1-999 Chemistry QD1-999 |
spellingShingle |
Physics QC1-999 Chemistry QD1-999 F. Yu Formation of large NAT particles and denitrification in polar stratosphere: possible role of cosmic rays and effect of solar activity |
topic_facet |
Physics QC1-999 Chemistry QD1-999 |
description |
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. |
format |
Article in Journal/Newspaper |
author |
F. Yu |
author_facet |
F. Yu |
author_sort |
F. Yu |
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 |
Copernicus Publications |
publishDate |
2004 |
url |
https://doaj.org/article/84d7cda9d0a7448cad877d31683d1866 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Atmospheric Chemistry and Physics, Vol 4, Iss 9/10, Pp 2273-2283 (2004) |
op_relation |
http://www.atmos-chem-phys.net/4/2273/2004/acp-4-2273-2004.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 1680-7316 1680-7324 https://doaj.org/article/84d7cda9d0a7448cad877d31683d1866 |
_version_ |
1766342966104817664 |