Watching the sun circle the pole

Icarus asked to see info on Arctic and Antarctic.
Since a graph of Arctic ice was posted earlier I added one for Antarctic.
Both clearly show increases.

 

I looked and could not find a good map of albedo going over years. If anyone has such a chart, I would like to see it, perhaps monthly would be best. I could find Greenland, which goes up some years, and down others but is in overall a downward trend (less icy).

One thing is pretty clear, ice grows in the winter and shrinks in the summer in the artic, and does the opposite in the antarctic. This is a natural process and there are yearly variations.

In the Artic, ice has been disappearing since the little ice age, in other words for over a hundred years, and decreased albedo has added to warming temperatures in the arctic. Ice does not shrink every year, some years it grows, but looked upon any longer period of time there is clear shrinkage, and we can assume shrinkage world wide as sea levels have risen without enough corresponding deacrease of contintental water/snow.

 

Antarctic Sea Ice Area Sets Another Record High | Real Science

 

One issue with Antarctic sea ice coverage (as opposed to Arctic sea ice) is the little understood effect of continental ice on sea ice. From what I understand, land ice is moving onto the sea, governing a net gain of sea ice, but a loss of total ice mass!

The issue is, in the net ice mass, not area of coverage. Clearly Arctic sea ice is diminishing, and I beleive that total Antarctic ice MASS is decreasing as well.

Icarus

 

If we are talking albedo, then the issue is area, not mass. Albedo does not care how thick the ice is as long as it isn't so thin it will no longer reflect the sun. If the mass shrinks enough this may be the case. Albedo does care about how clean the ice is. If there is soot covering it, it will not reflect the sun as well. One theory of loss of albedo is pollution. We can clearly see changes in these levels in the ice cores.

Ice mass matters when determining sea levels, and there is a better indication - the sea level. We can measure it directly. Ice mass changes are part of sea level predictions, so its important to measure the changes to see if these predictions are coming true. The satellite estimated mass levels show that the most optimistic and pessimistic theories are unlikely to be true. These show that calving is adding to sea level rise, but the Hansen estimates according to others looking at the data are entirely too pessimistic.

 

BBC News - Antarctic ice volume measured

The take away from this, (which chronicles the vast attempt to log continental ice mas in the Antarctic) is that modern mapping techniques has been able to discern that way more of Antarctic ice is actually sitting below sea level that was previously estimated. This translates to less potential sea level rise if that ice were to totally melt.

The shear cubic volume of Antarctic ice is staggering, in the millions of Cubic KMs. It also notes that the bulk of Antarctic ice mass loss is on the edges of the continent due to changes in ocean currents.

I would also note, that ice melt from sea ice actually reduces sea level rather than raises it! Sea ice is floating on the sea' and it's volume is greater as ice than as liquid water. I suppose then, that it is reasonable to assume that the melting sea ice is potentially offsetting some of the predicted rise as a result of grounded ice becoming either floating ice or liquid water.

Icarus

 

I agree, if we are simply talking about Albedo. Icarus

 

Bob that is mass, not area. The key to albedo is area, and that is the chart I would love to have.

The mass loss can be used in validating predictions in sea level rise. We all, well everyone that is actually following it, know that sea level rise has been accelerating since the end of the little ice age except for short periods of natural precipitation variation where it has fallen. The rise has accelerated in recent years, and expect for a few that don't look at the facts, some of this acceleration is due to ghg. The satellite measurements are key to validating theories about that acceleration. Preditions are all over the place from no rise to a 6 meter rise by 2100. The measurements in recent papers have pegged a likely rise between 0.2 meters to 0.6 meter, with over 2 extremely unlikely (> 3 sigma) with todays knowledge of calving mechanisms. Evidence from the last interglacial shows a gain of 5 meters higher sea level than today.

 

As requested above, a new albedo study appears

Three-decade decline in reflectivity of Arctic sea ice

click that doi and request your free pdf from the authors. Really, they are generally happy to oblige.

 

3% per decade! Over a 28 year study period! That my friends is a lot, and it shows no sign of slowing.

Icarus

 

Good data and a nice time period for observation. Are there similar studies of the antarctic?

 

You claimed increases in volume, but your links mention only area. These quantities are not equivalent.

An article discussed here many moons ago mentioned how heavy ice mass (i.e. volume) loss in some parts of Antarctica was flooding large portions of the local ocean surface with semi-fresh, or at least lower salinity, water. This permits easier formation of thin sea surface ice during winter, so ice area was increasing at the same time ice volume was falling.

This article was specific to the Antarctic, not the Arctic.

 

Re: #33, I don't know about antarctic albedo records. It should be easy to look for such things. The orbits of the satellites being used in the ref. I cited are clearly suitable.

Orbital mechanics tip: if you go over the north pole, it is not possible to avoid going over the south pole as well.