I am primarily sharing this featured image which can be found at the site:
and which has the citation:
U.S. Navy – Ice Atlas of the Northern Hemisphere, 1946, David Rumsey Map Collection, Original ~ 50 Mb file reduced 20% quality
It will serve as an initial case for future arctic hydroclimatology connections. I will likely continue to systematically comb through resources for my ongoing learning curve, especially as they may or may not relate to atmospheric marine aerosols.
First I note that likely many other amateurs as well as professionals have sifted through polar ice cap data. I found the wattsupwiththat site very helpful and also liked this site and recommend at
Also NASA provides some helpful screen shots of the annual minimum arctic ice cap at:
I’ve taken a screen shot for the year 2005 at that site and placed below. Nominally, if both this image and the featured 1946 image are to be accepted at face value to outline the minimum extents of un-navigable ice, then both cover similar domains.
I may have read that September of 2005 was a relatively low ice year and month. I’ve taken a related look at the geostrophic atmospheric height and circulation in the next image from the ERAI resource for the same year and month below. In these images, the white crosses represent origin points for steady state streamlines which I’ve inserted utilizing the ERAI zonal and merdional winds for the full atmosphere. The circulation patterns might suggest that summer southerly winds cross the Arctic Ocean from Eurasia, warming the sea surface and reducing the ice cap. I admit I have much to learn but in any case this is only a blog for fun and demonstrations.
The “average” conditions for the same month over the 36 years of satellite coverage from 1979 through 2014 are shown next. I am assuming that the average condition is associated with a greater icecap than the September 2005 condition. If so then the average map below may help confirm the speculations above. For one reason, the average condition doesn’t appear to express the eurasian continental southerlies.
I’ve also written in the past here on the “polar vortex” of early 2014 and included similar geostrophic plots which compared well.
Here are two more pairs, one for 2013 and one for 2014, all for September as customary. The first pair to follow cover the NASA polar coverage and my ERAI geostrophic wind vector streamline coverage (with pinkish to blue contours of geopotential height of the full atmosphere, Z again).
The next pair for September of 2014 follow with same parameters.
I think the geostrophic winds and associated vortexes seem to coincide with main icecap boundaries. This is no doubt common but perhaps not widely distributed knowledge. In any case at least to me it is satisfying to see the connections from these graphic perspectives.
Some papers attribute or otherwise relate significant concentrations of aerosols to temperatures and residence times in the atmosphere above the poles. I have already reviewed some ozone related material on this topic. Soon I’ll explore through the geostrophic and cyclostrophic maps a bit more on the possible residence times over, across, or through these polar regions.