Kaspari, S., Schwikowski, M., Gysel, M., Flanner, M.G., Kang, S. and Mayewski, P.A., 2011, Recent increase in black carbon concentrations from a Mt. Everest ice core spanning 1860-2000AD, Geophys. Res. Letts., doi:10.1029/2010GL046096,2011.