Black Carbon in Arctic Snow and its Effect on Surface Albedo

• Calibration filters which have known concentrations of soot (Monarch 128) are used to build a linear relationship between ln(Isample)/ln(Iblank), where Isample is the signal from the sample filter and Iblank is the signal from a blank filter. This is used to derive equivalent black carbon concentrations. These will differ from actual black carbon concentrations where (a) other light-absorbing material (such as desert dust or soil) are present or (b) if the mass absorption coefficient is different from that assumed for black carbon (6 m2/g).