This dataset contains the floe size distribution (FSD) data derived from high-resolution satellite imagery data acquired at two fixed locations in the Arctic Ocean. Satellite imagery data include MEDEA images and WorldView images. These satellite images have a spatial resolution of 1 m or higher, thus providing the FSD information, especially for small floes. The derived data contain floe size (calliper diameter), shape factor, minor/major axis, perimeter and area of the floes. This dataset has been used to evaluate the sea ice models with the FSD parameterisations. The retrieval of the FSD data was done by the University of Huddersfield team.
This work was funded by NERC standard grant NE/R000654/1 and NERC MOSAiC program NE/S002545/1.
Arctic, MOSAiC, brittle failure, floe size distribution, lateral melt, sea ice, wave fracture
Hwang, B., & Wang, Y. (2023). High-resolution floe size distribution of Arctic sea ice 2000-2014 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/6d65b406-237c-425d-9356-39b77ac30e85
|Access Constraints:||No restrictions apply.|
|Use Constraints:||Data supplied under Open Government Licence v3.0 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/.|
|ISO Topic Categories:||
|Name||UK Polar Data Centre|
|Organisation||British Antarctic Survey|
|Role(s)||Investigator, Technical Contact|
|Organisation||University of Huddersfield|
|Organisation||University of Huddersfield|
|Reference:||Wang, Y., Hwang, B., Bateson, A. W., Aksenov, Y., and Horvat, C.: Summer sea ice floe size distribution in the Arctic: High-resolution optical satellite imagery and model evaluation, The Cryosphere Discuss. [preprint], https://doi.org/10.5194/tc-2022-130, in review, 2022.
Hwang, B., J. Ren, S. McCormack, C. Berry, I. Ben Ayed, H. Graber, and E. Aptoula (2017) A practical algorithm for the retrieval of sea ice floe size distribution from high-resolution Synthetic Aperture Radar imagery, Elem Sci Anth, 2017;5:38. https://doi.org/10.1525/elementa.154
|Quality:||The data quality was checked by manual inspection for each imagery data. It should be noted that some of the small floes can be erroneous due to noises or internal variations within the images. However, no minimum threshold for the smallest detectable floes was set for this dataset (i.e., the smallest floe equals one image pixel). This is to provide flexibility for the users to determine the minimum threshold for the smallest detectable floes. For instance, in a model evaluation study, the minimum threshold was set to be 30 m (i.e., the floes small than 30 m in diameter were discarded from the analysis).|
|Lineage:||The FSD data were derived from high-resolution satellite imagery data (MEDEA and Worldview). For MEDEA images, the original images were cropped to remove the areas with clouds and missing data. The cropped images were then used to derive the FSD. For WorldView images, panchromatic images were used to derive the FSD. The floe size distribution was derived from those images using the algorithm described in Hwang et al. (2017).|
|Detailed Location||Chukchi Sea|
|Detailed Location||Fram Strait|
|Data Collection:||Characteristics of satellite imagery data used to derive the data set are described below.
MEDEA: 1-m resolution visible (panchromatic) satellite imagery from the USGS Global Fiducials Library (GFL) (https://glf.usgs.gov), declassified by the MEDEA group.
WorldView: A commercial satellite by Digital Globe (https://www.digitalglobe.com). The FSD data was derived from panchromatic images of WorldView-1 (WV1) and WorldView-2 (WV2).
|Distribution Media||Online Internet (HTTP)|
|Distribution Size||7.1 GB|
|Data Storage:||The dataset is organised in two folders, named chukchi and fram. The folder chukchi contains the FSD data derived at the Chukchi Sea site, and the folder fram contains the FSD data derived at the Fram Strait site. The two subfolders of MEDEA and WV contain the data derived from MEDEA and WV images respectively.
In each folder of MEDEA or WV, the data are contained in three folders of sat_image, floe_map and fsd. The folder sat_image contains the pre-processed satellite imagery data in GeoTIFF formatt (due to the license issue, the original satellite imagery data for Worldview images are not provided in the data set, only raw MEDEA images are provided). The folder floe_map contains the results in black-and-white images (black = water, white = ice) which were generated from the image segmentation, floe separation and manual inspection. The folder fsd contains the text data files generated from the floe map images using blob analysis (identifying individual ice floes from the images). Each FSD data file is accompanied by a corresponding PNG file that displays a visual plot of the data. The FSD data files are in CSV (comma separate values) with the data structure as below.
Mean caliper diameter of the floes
Ratio of the major axis to the minor axis of the floes (major axis / minor axis)
Length of the major axis of the floes
Length of the minor axis of the floes
Perimeter of the floes
Area of the floes
Number of the pixels for ice floes