soot

I hadn't thought of this, but of course the soot that has collected in ice in Greenland and Antarctica since the beginning of the industrial revolution will have soot embedded in it. When that ice melts, the soot won't. it will just collect in the melt water.

http://www.nasa.gov/topics/earth/features/glacier-debris.html

Meet Kimberly Casey: Studying How Debris Influences Glaciers
04.02.12

Kimberly Casey is a glaciologist who spends a fair amount of time in the office analyzing satellite data. But when she talks about her fieldwork on remote glaciers, one suspects she could do pretty well in a triathlon, too. Casey has carried 70-pound backpacks up mountain crossings in the Himalayas and waded ice-cold streams in the European Alps to collect samples and take measurements for her research on glacier debris pollution.

During her Ph.D. research, Casey studied six glacier sites around the world; from volcanically influenced glaciers in Iceland and New Zealand to dust-influenced glaciers in Nepal and Switzerland to bare-ice and soot-influenced glaciers in Norway. --> During her Ph.D. research, Casey studied six glacier sites around the world; from volcanically influenced ice fields in Iceland and New Zealand to bare-ice and soot-polluted glaciers in Norway.

Q&A With Kimberly Casey

Q. Why do you study particulate pollution on glaciers?

A. Dust, volcanic ash, and soot particles are deposited on glaciers worldwide. The color of particulates on a glacier surface determines the amount of solar energy absorbed, which affects how much a glacier melts. Volcanic ash can be grey or black, while dust tends to be brown or red-brown. The thickness of the dust and debris on a glacier affects its melt rate, too. Because glaciers are a key water resource in many parts of the world, it is important to understand how melt rates may be changing over time. Glaciers are also of key importance to understanding global climate: the amount of ice cover on Earth affects how solar radiation is absorbed and reflected from Earth's surface.


Q. What kinds of debris are most frequently found on glaciers?

A. Dust is very common, as well as soot. Volcanic ash, or tephra, is dependent on the glacier's geographic location relative to the volcano and the eruption frequency. Dust comes from Earth's large deserts, like the Sahara. It also comes from local geology. Soot can come from forest fires, from combustion of oil (for example, from our cars) and coal mines.

In case anyone is not familiar with the site, the "WattsUpWithThat" blog is run by Anthony Watts, who spins this story as part of his overall skepticism about whether carbon dioxide plays a role at all in climate change and proposer of the well-disproven speculation that the warming trend in the temperature record is, at least in part, an artifact of inadequacies at the sites of terrestrial weather stations. I would take his commentary with more than a few grains of salt...