Soot
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Soot |
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| The presence of particulates in the snow cover and at the ice surface can decrease the spectral albedo of the system at visible wavelengths where absorption by ice and water is small. Because of this, we were concerned that the release and local deposition of soot particles from fuel burned onboard the ship could impact both albedos and melt rates. We measured the levels of soot and other contaminants present in the snow and ice to allow us to evaluate the role of the background particulate levels in the spring and summer radiative energy balance. Most of the sampling was carried out on a 4x4-km grid centered on the ship, with a few samples taken up to 20 km from the ship. The particles were extracted by vacuum filtration of the meltwater immediately after melting the samples. The filters were compared on site with a reference set for preliminary estimates of mass concentration. They will be brought back to our laboratory for more precise analysis of composition and particle size distribution. As the plot indicates, ship contamination was not a factor in our measurements. |
Soot sampling locations.
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The Des Groseilliers from the air in July 1998. The immediate area around the ship was dirty. However, as results from the soot survey showed, soot levels quickly dropped to background levels a couple of hundred meters from the ship. |
Soot concentration (ng per liter) near the ship. |
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