Major 20th century changes of water-soluble humic-like substances (HULIS WS ) aerosol over Europe inferred from Alpine ice cores

Julien Guilhermet (1) , Suzanne Preunkert (1) , Didier Voisin (1) , Christine Baduel (1) , Michel Legrand (1)

1 LGGE - Laboratoire de glaciologie et géophysique de l'environnement

Using a newly developed method dedicated to measurements of water-soluble humic-like substances (HULIS WS) in atmospheric aerosol samples, the carbon mass quantification of HULIS WS in an Alpine ice core is achieved for the first time. The method is based on the extraction of HULIS WS with a weak anion-exchanger resin and the subsequent quantification of the extracted carbon fraction with a total organic carbon (TOC) analyzer. Measurements were performed along a Col du Dôme (4250 m above sea level, French Alps) ice core covering the 1920-2004 time period. The HULIS WS concentrations exhibit a well-marked seasonal cycle with winter minima close to 7 ppbC and summer maxima ranging between 10 and 50 ppbC. Whereas the winter HULIS WS concentrations remained unchanged over the twentieth century, the summer concentrations increased from 20 ppbC prior to the Second World War to 35 ppbC in the 1970-1990s. These different trends reflect the different types of HULIS WS sources in winter and summer. HULIS WS are mainly primarily emitted by domestic wood burning in winter and secondary in summer being produced from biogenic precursors. For unknown reason, the HULIS WS signal is found to be unusual in ice samples corresponding to World War II.

Domaines: Mécanique des structures [physics.class-ph]

Julien Guilhermet, Suzanne Preunkert, Didier Voisin, Christine Baduel, Michel Legrand. Major 20th century changes of water-soluble humic-like substances (HULIS WS ) aerosol over Europe inferred from Alpine ice cores. Journal of Geophysical Research: Atmospheres, 2013, 118 (9), pp.3869-3878. ⟨10.1002/jgrd.50201⟩. ⟨hal-02051670⟩