Terrestrial Snowmelt as a Precursor to Landfast Sea Ice Break-up in Hudson Bay and James Bay

Abstract

Numerous studies have been conducted to enhance our understanding of how climate change impacts landfast ice and its break-up in spring or summer. Yet, predictions of break-up timing have proven elusive illusive, and dependent on multiple environmental drivers. In this study, we investigate whether/to what extent snow melt on land adjacent to the coast can serve as a precursor to landfast ice break-up. For the study, we used MODIS snowmelt timing products to explore the pattern of snowmelt across the study area. This was compared against landfast ice break-up dates generated mainly from CIS ice-chart, across the Hudson Bay and James Bay coast. Snowmelt timings recorded across the study area followed the same latitudinal gradient as the landfast ice break-up dates, with almost a 50-day difference between the south and the north snowmelt and ice break-up timings. The data shows that the timing of landfast ice break-up across the Hudson Bay and James Bay region showed significantly stronger correlations with the timing of terrestrial snowmelt, as compared to air temperature thresholds, with an average 17-day gap observed between snowmelt to landfast ice break-up. Based on the observations, we believe snowmelt can be a reliable precursor to landfast ice break-up.

Résumé

De nombreuses études ont été menées pour mieux comprendre l’impact des changements climatiques sur la banquise côtière et sa rupture au printemps ou en été. Pourtant, les prédictions du moment de la rupture se sont avérées insaisissables, illusoires et dépendantes de multiples facteurs environnementaux. Dans cette étude, nous cherchons à savoir si, et dans quelle mesure, la fonte des neiges sur les terres adjacentes à la côte peut servir de précurseur à la rupture de la banquise côtière. Pour l’étude, nous avons utilisé les dates de la fonte des neiges dérivées des produits MODIS pour explorer le schéma de la fonte des neiges dans la zone d’étude. Ces données ont été comparées aux dates de rupture de la banquise côtière générées principalement à partir de la carte des glaces du SCG, sur la côte de la baie d’Hudson et de la baie James. Les périodes de fonte des neiges enregistrées dans la zone d’étude ont suivi le même gradient latitudinal que les dates de rupture de la banquise côtière, avec une différence de près de 50 jours entre les dates de fonte des neiges et de rupture au sud et au nord. Des corrélations significativement plus fortes ont été observées entre le moment de la rupture de la banquise côtière de la baie d’Hudson et de la baie James et le moment de la fonte des neiges terrestres, par rapport à des seuils de température de l’air, avec un écart moyen de 17 jours observé entre la fonte des neiges et la rupture de la banquise côtière. D’après ces observations, nous croyons que la fonte des neiges peut être un précurseur fiable de la rupture de la banquise côtière.

Acknowledgements

The authors thank all collaborators of the BaySys program and Manitoba Hydro. This work is a contribution to the Arctic Science Partnership (ASP, asp-net.org) and ArcticNet.

Authors Contributions

• Contributed to original data acquisition: KG.

• Contributed to analysis and interpretation of the data: All authors

• Drafted the article: KG.

• Revised the article: All authors.

• Approved the submitted version for publication: All authors

Disclosure statement

The authors have no competing interests to declare.

Data accessibility statement

The datasets used in this study are available in numerous websites and freely accessible. The sources of the primary datasets used in the study are as follows:

• Weekly ice charts from The Canadian Ice Service.

  (https://iceweb1.cis.ec.gc.ca/Archive/page1.xhtml?lang=en)

• Air temperature reanalysis products from ERA-5.

  (https://cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-single-levels?tab=overview)

• Snowmelt timing records from the Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC)

  (https://daac.ornl.gov/cgi-bin/dsviewer.pl?ds_id=1712)

Other datasets include satellite images from Landsat series (https://earthexplorer.usgs.gov/) and daily observations from the online viewing platform NASA Worldview (https://worldview.earthdata.nasa.gov/).

Additional information

Funding

This work is a contribution to the Natural Sciences and Engineering Council of Canada (NSERC) Collaborative Research and Development project: BaySys (CRDPJ 470028-14) led by D. Barber (Academic PI) and K. Sydor (Industry PI). Individual support from Canada Research Chair Tier 1 to David Barber, NSERC Discovery Grant to Jens Ehn and Canada Excellence Research Chair to Dortha Dahl-Jensen has been provided to Kaushik Gupta.

Notes on contributors

Kaushik Gupta

Kaushik Gupta (Lead author): Ph.D. Candidate, Center for Earth Observation Science, University of Manitoba, Canada.

Jens K. Ehn

Jens Ehn (Co-author): Assistant Professor, Center for Earth Observation Science, University of Manitoba, Canada.