All findings · Arctic Open-Water Window
Did Vilkitsky Strait still have ice-locked years in the latest decade?
Vilkitsky Strait stayed shut in 8 early years. It opened every year from 2016 through 2025.
Vilkitsky Strait had 8 seasons with zero open days in 1979-1988 and 0 such seasons in 2016-2025.
These numbers are Arctic Open-Water Window version 1.1, the published package (15 gates in version 1.1).
Chart
From the table
Reading
What the data shows
In 1979-1988, 8 full seasons at nsr-vilkitsky have open_days_15 equal to zero. In 2016-2025, that count is 0. Blank open_days values are not counted as zero.
Context
Why it matters
If you need both presence and length, read this with the Vilkitsky decade-mean finding. Together they show whether the gate opens at all in a season, and how long it stays open when it does.
Method
How it was measured
An open day is a day when average sea-ice concentration inside the gate polygon sits below the cutoff named in open_days_15. Partial seasons are left out. The early window is 1979 through 1988. The late window is 2016 through 2025. The difference is the later mean minus the earlier mean. A zero season is a full season whose open_days_15 value is zero. Blank values are not counted as zero. Method on the dataset page.
Limits
What this cannot tell you
Polygon average concentration, not ice thickness or a ship route. The 15 percent cutoff is the strictest of the three. Provisional near-real-time days can change. Early-decade means skip seasons with blank open_days_15. Disclaimer word for word: Not for navigation. Use at your own risk. Provided as is, without warranty of any kind.
Check
Check it yourself
- File
arctic/gate_seasons.csv- Column
open_days_15- Row
gate_id nsr-vilkitsky, partial not True, open_days_15 equal to zero, years 1979-1988 and 2016-2025- API and assistant
- Same key, same data
This API call reads the same cells.
curl "https://api.heimdallresearch.com/v1/arctic/gates/nsr-vilkitsky/seasons" \
-H "Authorization: Bearer $HEIMDALL_API_KEY"This assistant prompt asks for the same cells.
MCP https://api.heimdallresearch.com/mcp question: How many full nsr-vilkitsky seasons have open_days_15 equal to zero in 1979-1988 and in 2016-2025?Citation
Dataset citation
Heimdall Research (2026). Arctic Open-Water Window (Version 1.1) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.23147722 Concept DOI https://doi.org/10.5281/zenodo.23021977. New version of https://doi.org/10.5281/zenodo.23021978.
- Version
- 1.1
- DOI
- 10.5281/zenodo.23147722
Related
Related findings
-
Bering Strait is open 53 more days a year than it was
At Bering Strait, mean open days at the 15 percent cutoff rose from 143.2 days a year in 1979-1988 to 196.5 days in 2016-2025 (difference +53.3 days).
Breakdown
For bering-strait, mean open_days_15 on full seasons with a numeric value is 143.2 in 1979-1988 (n=8) and 196.5 in 2016-2025 (n=10). The difference is +53.3 days. Seasons with a blank open_days_15 are skipped.
-
A typical year at Bering Strait has 173 open days
Over 45 full seasons (1979 to 2025), Bering Strait had a median of 173 open days at the 15 percent cutoff (range 118 to 234).
Breakdown
The gate_trends row for bering-strait at threshold 15 reports median_open_days 173.0 over 45 seasons (2 excluded). Across non-blank open_days_15 values in gate_seasons, the range is 118 to 234.
-
Barrow Strait, Canada: 11 open days a year in 1979-1988, 51 in 2016-2025.
At Barrow Strait, mean open days at the 15 percent cutoff rose from 11.1 days a year in 1979-1988 to 51.3 days in 2016-2025 (difference +40.2 days).
Breakdown
For nwp-barrow, mean open_days_15 on full seasons with a numeric value is 11.1 in 1979-1988 (n=9) and 51.3 in 2016-2025 (n=10). The difference is +40.2 days.
Not for navigation. Use at your own risk. Provided as is, without warranty of any kind.
Provided as is, without warranty of any kind.