Regional melt-pond fraction and albedo of thin Arctic first-year drift ice in late summer
The paper presents a case study of the regional (≈150 km) morphological and optical properties of a relatively thin, 70–90 cm modal thickness, first-year Arctic sea ice pack in an advanced stage of melt. The study combines in situ broadband albedo measurements representative of the four main surface...
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ftdoajarticles:oai:doaj.org/article:26cf5e87a9e74c228c61423bfa725ef5 2023-05-15T13:10:33+02:00 Regional melt-pond fraction and albedo of thin Arctic first-year drift ice in late summer D. V. Divine M. A. Granskog S. R. Hudson C. A. Pedersen T. I. Karlsen S. A. Divina A. H. H. Renner S. Gerland 2015-02-01T00:00:00Z https://doi.org/10.5194/tc-9-255-2015 https://doaj.org/article/26cf5e87a9e74c228c61423bfa725ef5 EN eng Copernicus Publications http://www.the-cryosphere.net/9/255/2015/tc-9-255-2015.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-9-255-2015 https://doaj.org/article/26cf5e87a9e74c228c61423bfa725ef5 The Cryosphere, Vol 9, Iss 1, Pp 255-268 (2015) Environmental sciences GE1-350 Geology QE1-996.5 article 2015 ftdoajarticles https://doi.org/10.5194/tc-9-255-2015 2022-12-31T04:34:07Z The paper presents a case study of the regional (≈150 km) morphological and optical properties of a relatively thin, 70–90 cm modal thickness, first-year Arctic sea ice pack in an advanced stage of melt. The study combines in situ broadband albedo measurements representative of the four main surface types (bare ice, dark melt ponds, bright melt ponds and open water) and images acquired by a helicopter-borne camera system during ice-survey flights. The data were collected during the 8-day ICE12 drift experiment carried out by the Norwegian Polar Institute in the Arctic, north of Svalbard at 82.3° N, from 26 July to 3 August 2012. A set of > 10 000 classified images covering about 28 km 2 revealed a homogeneous melt across the study area with melt-pond coverage of ≈ 0.29 and open-water fraction of ≈ 0.11. A decrease in pond fractions observed in the 30 km marginal ice zone (MIZ) occurred in parallel with an increase in open-water coverage. The moving block bootstrap technique applied to sequences of classified sea-ice images and albedo of the four surface types yielded a regional albedo estimate of 0.37 (0.35; 0.40) and regional sea-ice albedo of 0.44 (0.42; 0.46). Random sampling from the set of classified images allowed assessment of the aggregate scale of at least 0.7 km 2 for the study area. For the current setup configuration it implies a minimum set of 300 images to process in order to gain adequate statistics on the state of the ice cover. Variance analysis also emphasized the importance of longer series of in situ albedo measurements conducted for each surface type when performing regional upscaling. The uncertainty in the mean estimates of surface type albedo from in situ measurements contributed up to 95% of the variance of the estimated regional albedo, with the remaining variance resulting from the spatial inhomogeneity of sea-ice cover. Article in Journal/Newspaper albedo Arctic ice pack Norwegian Polar Institute Sea ice Svalbard The Cryosphere Directory of Open Access Journals: DOAJ Articles Arctic Svalbard The Cryosphere 9 1 255 268 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 D. V. Divine M. A. Granskog S. R. Hudson C. A. Pedersen T. I. Karlsen S. A. Divina A. H. H. Renner S. Gerland Regional melt-pond fraction and albedo of thin Arctic first-year drift ice in late summer |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
The paper presents a case study of the regional (≈150 km) morphological and optical properties of a relatively thin, 70–90 cm modal thickness, first-year Arctic sea ice pack in an advanced stage of melt. The study combines in situ broadband albedo measurements representative of the four main surface types (bare ice, dark melt ponds, bright melt ponds and open water) and images acquired by a helicopter-borne camera system during ice-survey flights. The data were collected during the 8-day ICE12 drift experiment carried out by the Norwegian Polar Institute in the Arctic, north of Svalbard at 82.3° N, from 26 July to 3 August 2012. A set of > 10 000 classified images covering about 28 km 2 revealed a homogeneous melt across the study area with melt-pond coverage of ≈ 0.29 and open-water fraction of ≈ 0.11. A decrease in pond fractions observed in the 30 km marginal ice zone (MIZ) occurred in parallel with an increase in open-water coverage. The moving block bootstrap technique applied to sequences of classified sea-ice images and albedo of the four surface types yielded a regional albedo estimate of 0.37 (0.35; 0.40) and regional sea-ice albedo of 0.44 (0.42; 0.46). Random sampling from the set of classified images allowed assessment of the aggregate scale of at least 0.7 km 2 for the study area. For the current setup configuration it implies a minimum set of 300 images to process in order to gain adequate statistics on the state of the ice cover. Variance analysis also emphasized the importance of longer series of in situ albedo measurements conducted for each surface type when performing regional upscaling. The uncertainty in the mean estimates of surface type albedo from in situ measurements contributed up to 95% of the variance of the estimated regional albedo, with the remaining variance resulting from the spatial inhomogeneity of sea-ice cover. |
format |
Article in Journal/Newspaper |
author |
D. V. Divine M. A. Granskog S. R. Hudson C. A. Pedersen T. I. Karlsen S. A. Divina A. H. H. Renner S. Gerland |
author_facet |
D. V. Divine M. A. Granskog S. R. Hudson C. A. Pedersen T. I. Karlsen S. A. Divina A. H. H. Renner S. Gerland |
author_sort |
D. V. Divine |
title |
Regional melt-pond fraction and albedo of thin Arctic first-year drift ice in late summer |
title_short |
Regional melt-pond fraction and albedo of thin Arctic first-year drift ice in late summer |
title_full |
Regional melt-pond fraction and albedo of thin Arctic first-year drift ice in late summer |
title_fullStr |
Regional melt-pond fraction and albedo of thin Arctic first-year drift ice in late summer |
title_full_unstemmed |
Regional melt-pond fraction and albedo of thin Arctic first-year drift ice in late summer |
title_sort |
regional melt-pond fraction and albedo of thin arctic first-year drift ice in late summer |
publisher |
Copernicus Publications |
publishDate |
2015 |
url |
https://doi.org/10.5194/tc-9-255-2015 https://doaj.org/article/26cf5e87a9e74c228c61423bfa725ef5 |
geographic |
Arctic Svalbard |
geographic_facet |
Arctic Svalbard |
genre |
albedo Arctic ice pack Norwegian Polar Institute Sea ice Svalbard The Cryosphere |
genre_facet |
albedo Arctic ice pack Norwegian Polar Institute Sea ice Svalbard The Cryosphere |
op_source |
The Cryosphere, Vol 9, Iss 1, Pp 255-268 (2015) |
op_relation |
http://www.the-cryosphere.net/9/255/2015/tc-9-255-2015.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-9-255-2015 https://doaj.org/article/26cf5e87a9e74c228c61423bfa725ef5 |
op_doi |
https://doi.org/10.5194/tc-9-255-2015 |
container_title |
The Cryosphere |
container_volume |
9 |
container_issue |
1 |
container_start_page |
255 |
op_container_end_page |
268 |
_version_ |
1766233787217215488 |