For the first few decades of satellite observations, open water passages through the Arctic Ocean rarely formed.
Now, there is open water along the Russian and/or Canadian coast for 40+ days a year.
Now, there is open water along the Russian and/or Canadian coast for 40+ days a year.
Comments
Prior to ~2007, such passages were rare. Now, ships without ice breaking support can easily pass through the Arctic Ocean for roughly 2 months per year.