Aerosols: Black Carbon and Sulfate

With so many uncertainties attached to climate change, it is important to look at all of the factors. As early as 1896, scientists have been analyzing the presence of black carbon in the atmosphere. This group of three datasets looks at the presence of aerosols in the Earth's atmosphere. The first dataset contains only black carbon optical thickness, the second has sulfate optical thickness and the third has a combination of both black carbon and sulfate optical thickness. The data is from January 31, 2007 and extends out 120 hours through February 4, 2007. Black carbon is commonly known as soot. It is generated from burning fossil fuels and biomass fuels. Soot is the result of incomplete combustion, especially of coal, diesel fuels, biofuels and other biomass burnings. Sulfate is the result of sulfur dioxide and sulfur trioxide interacting with other compounds in the atmosphere. Sulfate aerosols in the atmosphere are associated with the combustion of fossil fuels and also the eruption of volcanoes like Mt. Pinatubo.

A large source of black carbon is from China and India, where most cooking and heating are done with wood, coal, and other biofuels at a low temperature that hinders that complete combustion of the compounds. Both black carbon and sulfate affect the global temperature by interacting with sunlight. It is thought that the presence of sulfate lowers the total mean global temperature by reflecting away incoming solar radiation. Conversely, black carbon absorbs the sunlight that reaches it, causing the air temperature to rise. This rise in air temperature causes convection and has been proven to change the hydrological cycle. Some flooding in China has been blamed on the high presence of black carbon. The Northern Hemisphere produces many more aerosols than the Southern Hemisphere largely because there are more people living in the Northern Hemisphere.