ATTENUATION OF VISIBLE LIGHT BY FALLING SNOW.
The attenuation of visible light by falling snow was studied by making simultaneous attenuation measurements and snow concentration measurements. The attenuation coefficient was calculated from photometric measurements and from visual observations. Snow concentration in the air was evaluated by two...
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ftdtic:AD0702905 2023-05-15T16:37:47+02:00 ATTENUATION OF VISIBLE LIGHT BY FALLING SNOW. O'Brien,Harold W. COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H 1969-06 text/html http://www.dtic.mil/docs/citations/AD0702905 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0702905 en eng http://www.dtic.mil/docs/citations/AD0702905 APPROVED FOR PUBLIC RELEASE DTIC AND NTIS Snow Ice and Permafrost Optics (*SNOW LIGHT TRANSMISSION) (*LIGHT ATTENUATION) ELECTROMAGNETISM PARTICLE SIZE VISIBILITY SAMPLING PHOTOMETERS OPTICAL ANALYSIS MEASUREMENT Text 1969 ftdtic 2016-02-18T23:07:18Z The attenuation of visible light by falling snow was studied by making simultaneous attenuation measurements and snow concentration measurements. The attenuation coefficient was calculated from photometric measurements and from visual observations. Snow concentration in the air was evaluated by two methods: from Formvar replicas collected during the snowfall, and by mass accumulation of snow in collecting pans. The snowflakes were arbitrarily classified by crystal types according to their estimated fall velocity. It was found that the correlation between extinction coefficient (attenuation) and snow concentration was generally much higher by types than when all snowflakes were considered together regardless of crystal components and degree of riming. Two types, apparently improperly classified, displayed lower correlations than the overall group. When no fog is present during the snowfall, the experimental results coincide well with attenuation theory if a reasonable correction is applied to the values obtained in the measurement of snowflake diameters. Measurements of mass flux indicate that for a given intensity the attenuation caused by snow is an order of magnitude greater than that caused by the same mass flux of rain. (Author) Text Ice permafrost Defense Technical Information Center: DTIC Technical Reports database |
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Open Polar |
collection |
Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Snow Ice and Permafrost Optics (*SNOW LIGHT TRANSMISSION) (*LIGHT ATTENUATION) ELECTROMAGNETISM PARTICLE SIZE VISIBILITY SAMPLING PHOTOMETERS OPTICAL ANALYSIS MEASUREMENT |
spellingShingle |
Snow Ice and Permafrost Optics (*SNOW LIGHT TRANSMISSION) (*LIGHT ATTENUATION) ELECTROMAGNETISM PARTICLE SIZE VISIBILITY SAMPLING PHOTOMETERS OPTICAL ANALYSIS MEASUREMENT O'Brien,Harold W. ATTENUATION OF VISIBLE LIGHT BY FALLING SNOW. |
topic_facet |
Snow Ice and Permafrost Optics (*SNOW LIGHT TRANSMISSION) (*LIGHT ATTENUATION) ELECTROMAGNETISM PARTICLE SIZE VISIBILITY SAMPLING PHOTOMETERS OPTICAL ANALYSIS MEASUREMENT |
description |
The attenuation of visible light by falling snow was studied by making simultaneous attenuation measurements and snow concentration measurements. The attenuation coefficient was calculated from photometric measurements and from visual observations. Snow concentration in the air was evaluated by two methods: from Formvar replicas collected during the snowfall, and by mass accumulation of snow in collecting pans. The snowflakes were arbitrarily classified by crystal types according to their estimated fall velocity. It was found that the correlation between extinction coefficient (attenuation) and snow concentration was generally much higher by types than when all snowflakes were considered together regardless of crystal components and degree of riming. Two types, apparently improperly classified, displayed lower correlations than the overall group. When no fog is present during the snowfall, the experimental results coincide well with attenuation theory if a reasonable correction is applied to the values obtained in the measurement of snowflake diameters. Measurements of mass flux indicate that for a given intensity the attenuation caused by snow is an order of magnitude greater than that caused by the same mass flux of rain. (Author) |
author2 |
COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H |
format |
Text |
author |
O'Brien,Harold W. |
author_facet |
O'Brien,Harold W. |
author_sort |
O'Brien,Harold W. |
title |
ATTENUATION OF VISIBLE LIGHT BY FALLING SNOW. |
title_short |
ATTENUATION OF VISIBLE LIGHT BY FALLING SNOW. |
title_full |
ATTENUATION OF VISIBLE LIGHT BY FALLING SNOW. |
title_fullStr |
ATTENUATION OF VISIBLE LIGHT BY FALLING SNOW. |
title_full_unstemmed |
ATTENUATION OF VISIBLE LIGHT BY FALLING SNOW. |
title_sort |
attenuation of visible light by falling snow. |
publishDate |
1969 |
url |
http://www.dtic.mil/docs/citations/AD0702905 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0702905 |
genre |
Ice permafrost |
genre_facet |
Ice permafrost |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/AD0702905 |
op_rights |
APPROVED FOR PUBLIC RELEASE |
_version_ |
1766028091030765568 |