Effects of black carbon and Icelandic dust on snow albedo, melt and density
Light-absorbing impurities in the cryosphere are of hydrological, environmental and climatic importance. The wet and dry deposition of black carbon (BC), organic carbon (OC), and dust particles affect the optical properties and melt of snow and ice. In the Arctic region, the climatic effects are amp...
Main Author: | |
---|---|
Format: | Thesis |
Language: | English |
Published: |
Finnish Meteorological Institute
2016
|
Subjects: | |
Online Access: | http://hdl.handle.net/10138/169074 |
id |
ftunivhelsihelda:oai:helda.helsinki.fi:10138/169074 |
---|---|
record_format |
openpolar |
spelling |
ftunivhelsihelda:oai:helda.helsinki.fi:10138/169074 2023-08-20T03:59:16+02:00 Effects of black carbon and Icelandic dust on snow albedo, melt and density Meinander, Outi 2016-11-17T09:55:27Z application/pdf http://hdl.handle.net/10138/169074 eng eng Finnish Meteorological Institute Finnish Meteorological Institute Contributions 125 0782-6117 978-951-697-896-6 http://hdl.handle.net/10138/169074 arctic aerosol black carbon Iceland dust albedo snow ice Thesis 2016 ftunivhelsihelda 2023-07-28T06:13:06Z Light-absorbing impurities in the cryosphere are of hydrological, environmental and climatic importance. The wet and dry deposition of black carbon (BC), organic carbon (OC), and dust particles affect the optical properties and melt of snow and ice. In the Arctic region, the climatic effects are amplified, and surface albedo feedback is often cited as the main contributor. The aim of this thesis is to fill in some of the gaps in our knowledge of the effects of BC, OC, and Icelandic dust on snow in the European Arctic through a series of field and laboratory experiments and an analysis of the resulting data, including modeling. The thesis presents a new hypothesis on the snow density effects of light-absorbing impurities, an important quantity for climate modeling and remote sensing. Three processes are suggested to explain the proposed ”BC density effect”. Experimental results show that dirty snow releases melt water quicker than cleaner snow. The albedo of natural seasonally melting snow in Sodankylä, north of the Arctic Circle, is found to be asymmetric with respect to solar midday, thus indicating a change in the properties of the snow. The radiative transfer modeling results show that the observed solar zenith angle asymmetry results in a 2–4 % daily error for satellite snow albedo estimates. Surface albedo model results indicate that the biggest snow albedo changes due to BC are expected in the ultraviolet (UV) part of the electromagnetic spectrum. The albedo of natural seasonal snow measured in Sodankylä, is found to be lower than expected. Solar UV and visible (VIS) albedo values of 0.6–0.8 in the accumulation period and 0.5–0.7 during melting are observed. The low albedo values are explained to be due to large snow grain sizes up to ∼3 mm in diameter, meltwater surrounding the grains and increasing the effective grain size, and absorption caused by impurities in the natural snow (87 ppb BC and 2894 ppb OC). The BC contents of the surface snow layer at the Sodankylä Arctic Research Center, Finland, is ... Thesis albedo Arctic black carbon Iceland Sodankylä Helsingfors Universitet: HELDA – Helsingin yliopiston digitaalinen arkisto Arctic Sodankylä ENVELOPE(26.600,26.600,67.417,67.417) |
institution |
Open Polar |
collection |
Helsingfors Universitet: HELDA – Helsingin yliopiston digitaalinen arkisto |
op_collection_id |
ftunivhelsihelda |
language |
English |
topic |
arctic aerosol black carbon Iceland dust albedo snow ice |
spellingShingle |
arctic aerosol black carbon Iceland dust albedo snow ice Meinander, Outi Effects of black carbon and Icelandic dust on snow albedo, melt and density |
topic_facet |
arctic aerosol black carbon Iceland dust albedo snow ice |
description |
Light-absorbing impurities in the cryosphere are of hydrological, environmental and climatic importance. The wet and dry deposition of black carbon (BC), organic carbon (OC), and dust particles affect the optical properties and melt of snow and ice. In the Arctic region, the climatic effects are amplified, and surface albedo feedback is often cited as the main contributor. The aim of this thesis is to fill in some of the gaps in our knowledge of the effects of BC, OC, and Icelandic dust on snow in the European Arctic through a series of field and laboratory experiments and an analysis of the resulting data, including modeling. The thesis presents a new hypothesis on the snow density effects of light-absorbing impurities, an important quantity for climate modeling and remote sensing. Three processes are suggested to explain the proposed ”BC density effect”. Experimental results show that dirty snow releases melt water quicker than cleaner snow. The albedo of natural seasonally melting snow in Sodankylä, north of the Arctic Circle, is found to be asymmetric with respect to solar midday, thus indicating a change in the properties of the snow. The radiative transfer modeling results show that the observed solar zenith angle asymmetry results in a 2–4 % daily error for satellite snow albedo estimates. Surface albedo model results indicate that the biggest snow albedo changes due to BC are expected in the ultraviolet (UV) part of the electromagnetic spectrum. The albedo of natural seasonal snow measured in Sodankylä, is found to be lower than expected. Solar UV and visible (VIS) albedo values of 0.6–0.8 in the accumulation period and 0.5–0.7 during melting are observed. The low albedo values are explained to be due to large snow grain sizes up to ∼3 mm in diameter, meltwater surrounding the grains and increasing the effective grain size, and absorption caused by impurities in the natural snow (87 ppb BC and 2894 ppb OC). The BC contents of the surface snow layer at the Sodankylä Arctic Research Center, Finland, is ... |
format |
Thesis |
author |
Meinander, Outi |
author_facet |
Meinander, Outi |
author_sort |
Meinander, Outi |
title |
Effects of black carbon and Icelandic dust on snow albedo, melt and density |
title_short |
Effects of black carbon and Icelandic dust on snow albedo, melt and density |
title_full |
Effects of black carbon and Icelandic dust on snow albedo, melt and density |
title_fullStr |
Effects of black carbon and Icelandic dust on snow albedo, melt and density |
title_full_unstemmed |
Effects of black carbon and Icelandic dust on snow albedo, melt and density |
title_sort |
effects of black carbon and icelandic dust on snow albedo, melt and density |
publisher |
Finnish Meteorological Institute |
publishDate |
2016 |
url |
http://hdl.handle.net/10138/169074 |
long_lat |
ENVELOPE(26.600,26.600,67.417,67.417) |
geographic |
Arctic Sodankylä |
geographic_facet |
Arctic Sodankylä |
genre |
albedo Arctic black carbon Iceland Sodankylä |
genre_facet |
albedo Arctic black carbon Iceland Sodankylä |
op_relation |
Finnish Meteorological Institute Contributions 125 0782-6117 978-951-697-896-6 http://hdl.handle.net/10138/169074 |
_version_ |
1774724817993334784 |