I noticed an odd report that overstated the ice situation and this woke me up to put up an update. This year, the north west passage has remain closed off and quite badly as well. No one is going through there this year. In fact it would be challenging for a viking long boat as well although the southern route is reachable and it is clear.
Yet the total ice cover remains close to the now established 2008 - 2018 channel to keep that fully intact. The Russian route is also wide open and you could sail a fleet through there.
The restoration of Medieval sea ice conditions continues and that particular cycle lasted several centuries and allowed a steady movement of support and trade between Greenland and Vinland which was the Cowichan valley on Vancouver Island.
Considering that it should also be quite apparent that they also established meaningful Walrus hunting bases on Ungava and through to Hudson Bay. It is also plausible that they built out a community in James Bay far earlier than their actual abandonment of Greenland. Thus actual abandonment, although necessarily organized and taking at least two seasons was also well fed through the walrus hunt. At the same time they would have used their shipping to move as many as possible to New England which could not absorb more than a few hundred from a population reported to be 10,000. The walrus hunt was close by and a handful of ships could move hundreds every week to Ungava.
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Current State of the Sea Ice Cover
J. C. Comiso, C. L. Parkinson, T. Markus, D. J. Cavalieri and R. Gersten
https://neptune.gsfc.nasa.gov/csb/index.php?section=234
The sea ice cover is one of the key components of
the polar climate system. It has been a focus of attention in recent
years, largely because of a strong decrease in the Arctic sea ice cover
and modeling results that indicate that global warming could be
amplified in the Arctic on account of ice-albedo feedback. This results
from the high reflectivity (albedo) of the sea ice compared to ice-free
waters. A satellite-based data record starting in late 1978 shows that
indeed rapid changes have been occurring in the Arctic, where the ice
coverage has been declining at a substantial rate. In contrast, in the
Antarctic the sea ice coverage has been increasing although at a lesser
rate than the decreases in the Arctic. Shown below are up-to-date
satellite observations of the sea ice covers of both the Arctic and the
Antarctic, along with comparisons with the historical satellite record
of more than 37 years. The plots and color-coded maps are chosen to
provide information about the current state of the sea ice cover and how
the most current daily data available compare with the record lows and
record highs for the same date during the satellite era. Sea ice
concentration is the percent areal coverage of ice within the data
element (grid cell). Sea ice extent is the integral sum of the areas of
all grid cells with at least 15% ice concentration, while sea ice area
is the integral sum of the product of ice concentration and area of all
grid cells with at least 15% ice concentration. The dashed vertical
line indicates the date of the latest plotted and mapped data.
Figure 1: 10-year averages between
1979 and 2008 and yearly averages for 2007, 2012, and 2016 of the daily
(a) ice extent and (b) ice area in the Northern Hemisphere and a listing
of the extent and area of the current, historical mean, minimum, and
maximum values in km2.
Figure 2: Color-coded map of the
daily sea ice concentration in the Northern Hemisphere for the indicated
recent date along with the contours of the 15% edge during the years
with the least extent of ice (in red) and the greatest extent of ice (in
yellow) during the period from November 1978 to the present. The
extents in km2 for the current and for the years of minimum
and maximum extents are provided below the image. The different shades
of gray over land indicate the land elevation with the lightest gray
being the highest elevation.
Figure 3: 10-year averages between
1979 and 2008 and yearly averages for 2012, 2014, and 2016 of the daily
(a) ice extent and (b) ice area in the Southern Hemisphere and a listing
of the extent and area of the current, historical mean, minimum, and
maximum values in km2.
Figure 4: Color-coded map of the
daily sea ice concentration in the Southern Hemisphere for the indicated
recent date along with the contours of the 15% edge during the years
with the least extent of ice (in red) and the greatest extent of ice (in
yellow) during the period from November 1978 to the present. The
extents in km2 for the current and for the years of minimum
and maximum extents are provided below the image. The different shades
of gray over land indicate the land elevation with the lightest gray
being the highest elevation.
Figure 5. Seasonal cycle of
Northern Hemisphere sea ice extents (a) and areas (b), given as daily
averages, for the years 2007 through 2016. The vertical line represents
the last data point plotted.
Figure 6. Seasonal cycle of
Southern Hemisphere sea ice extents (a) and areas (b), given as daily
averages, for the years 2007 through 2016. The vertical line represents
the last data point plotted.
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