Extinction of UV-visible radiation in wet midlatitude (maritime) snow: Implications for increased NOx emission
A field and modeling study of the optical properties of wet midlatitude (maritime) mountainous snowpack is presented. The snowpacks were found to have greater UV penetration depths than polar (tundra) snowpacks and consequently may release more NO2 gas to the atmosphere during the photolytic destruc...
Published in: | Journal of Geophysical Research |
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Language: | English |
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American Geophysical Union
2005
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Online Access: | http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-005-224 https://doi.org/10.1029/2005JD005963 |
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ftncar:oai:drupal-site.org:articles_7483 2023-10-01T03:59:56+02:00 Extinction of UV-visible radiation in wet midlatitude (maritime) snow: Implications for increased NOx emission Fisher, F. (author) King, M. (author) Lee-Taylor, Julia (author) 2005-11-02 application/pdf http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-005-224 https://doi.org/10.1029/2005JD005963 en eng American Geophysical Union Journal of Geophysical Research-Atmospheres http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-005-224 doi:10.1029/2005JD005963 ark:/85065/d7j67h8m Copyright 2005 American Geophysical Union. Text article 2005 ftncar https://doi.org/10.1029/2005JD005963 2023-09-04T18:28:04Z A field and modeling study of the optical properties of wet midlatitude (maritime) mountainous snowpack is presented. The snowpacks were found to have greater UV penetration depths than polar (tundra) snowpacks and consequently may release more NO2 gas to the atmosphere during the photolytic destruction of nitrate anions in the snowpack for a given spherical irradiance. Fluxes of NO2 to the troposphere as a result of NO3- photolysis were calculated for different measured e-folding depths using tropospheric ultraviolet-visible (TUV)-modeled actinic flux data assuming all the NO2 can leave the snowpack and the photolysis of nitrate is the rate-limiting step. These calculated fluxes ranged from 3.3 to 7.6 kg km(-2) yr(-1) (assuming 150 days of snow cover a year), significantly more than polar snowpacks by a factor of 4-10. The fieldwork measured liquid equivalent e-folding depths of 3.74-14.66 cm (e-folding depths of 7.25-32.4 cm(-1)) at four sites in the Cairngorm mountain range, Scotland (57 degrees 07 ' N, 3 degrees 40 ' W), during the winter of 2003. The wavelength range studied was 300-450 nm. The snowpacks consisted predominantly of windblown rounded grains ranging from 0.1 to 1.5 mm in diameter. The liquid water content of the snowpacks varied between the sites, which were visited up to three times to observe temporal changes in the physical composition and optical properties of the snowpack. The snowpack was modeled using the TUV radiative-transfer model, calculating scattering cross sections (sigma(scatt)) between 1 and 5 m(2) kg(-1). The absorption coefficient due to impurities (sigma(+)(abs)) was also modeled and was found to be approximately 1.0 cm 2 kg(-1). Three optically different snowpack categories are suggested: cold, dry polar (tundra) snowpacks, sigma(scatt) = 20-30 m(2) kg(-1); warmer polar coastal (maritime) snowpacks, sigma(scatt) = 6-13 m(2) kg(-1); and melting midlatitude mountainous (maritime) snow, sigma(scatt) = 1-5 m(2) kg(-1). Thus for midlatitude wet snow, 85% of photochemistry is ... Article in Journal/Newspaper Tundra OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Journal of Geophysical Research 110 D21 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
description |
A field and modeling study of the optical properties of wet midlatitude (maritime) mountainous snowpack is presented. The snowpacks were found to have greater UV penetration depths than polar (tundra) snowpacks and consequently may release more NO2 gas to the atmosphere during the photolytic destruction of nitrate anions in the snowpack for a given spherical irradiance. Fluxes of NO2 to the troposphere as a result of NO3- photolysis were calculated for different measured e-folding depths using tropospheric ultraviolet-visible (TUV)-modeled actinic flux data assuming all the NO2 can leave the snowpack and the photolysis of nitrate is the rate-limiting step. These calculated fluxes ranged from 3.3 to 7.6 kg km(-2) yr(-1) (assuming 150 days of snow cover a year), significantly more than polar snowpacks by a factor of 4-10. The fieldwork measured liquid equivalent e-folding depths of 3.74-14.66 cm (e-folding depths of 7.25-32.4 cm(-1)) at four sites in the Cairngorm mountain range, Scotland (57 degrees 07 ' N, 3 degrees 40 ' W), during the winter of 2003. The wavelength range studied was 300-450 nm. The snowpacks consisted predominantly of windblown rounded grains ranging from 0.1 to 1.5 mm in diameter. The liquid water content of the snowpacks varied between the sites, which were visited up to three times to observe temporal changes in the physical composition and optical properties of the snowpack. The snowpack was modeled using the TUV radiative-transfer model, calculating scattering cross sections (sigma(scatt)) between 1 and 5 m(2) kg(-1). The absorption coefficient due to impurities (sigma(+)(abs)) was also modeled and was found to be approximately 1.0 cm 2 kg(-1). Three optically different snowpack categories are suggested: cold, dry polar (tundra) snowpacks, sigma(scatt) = 20-30 m(2) kg(-1); warmer polar coastal (maritime) snowpacks, sigma(scatt) = 6-13 m(2) kg(-1); and melting midlatitude mountainous (maritime) snow, sigma(scatt) = 1-5 m(2) kg(-1). Thus for midlatitude wet snow, 85% of photochemistry is ... |
author2 |
Fisher, F. (author) King, M. (author) Lee-Taylor, Julia (author) |
format |
Article in Journal/Newspaper |
title |
Extinction of UV-visible radiation in wet midlatitude (maritime) snow: Implications for increased NOx emission |
spellingShingle |
Extinction of UV-visible radiation in wet midlatitude (maritime) snow: Implications for increased NOx emission |
title_short |
Extinction of UV-visible radiation in wet midlatitude (maritime) snow: Implications for increased NOx emission |
title_full |
Extinction of UV-visible radiation in wet midlatitude (maritime) snow: Implications for increased NOx emission |
title_fullStr |
Extinction of UV-visible radiation in wet midlatitude (maritime) snow: Implications for increased NOx emission |
title_full_unstemmed |
Extinction of UV-visible radiation in wet midlatitude (maritime) snow: Implications for increased NOx emission |
title_sort |
extinction of uv-visible radiation in wet midlatitude (maritime) snow: implications for increased nox emission |
publisher |
American Geophysical Union |
publishDate |
2005 |
url |
http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-005-224 https://doi.org/10.1029/2005JD005963 |
genre |
Tundra |
genre_facet |
Tundra |
op_relation |
Journal of Geophysical Research-Atmospheres http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-005-224 doi:10.1029/2005JD005963 ark:/85065/d7j67h8m |
op_rights |
Copyright 2005 American Geophysical Union. |
op_doi |
https://doi.org/10.1029/2005JD005963 |
container_title |
Journal of Geophysical Research |
container_volume |
110 |
container_issue |
D21 |
_version_ |
1778534465945993216 |