|CARBOPAST - Carbonaceous aerosol over Europe: the past 100 years as inferred from an Alpine ice core|
Programme - Programa Pessoa
Execution dates - 2012-01-01 - 2012-12-31 (12 Months)
Funding Entity - FCT
Total Funding - 2500 €
Proponent Institution - Universidade de Aveiro
Laboratoire de Glaciologie et Géophysique de l’Environnement UMR (LGGE), Grenoble, France
In the framework of the European CARBOSOL project (Present and Retrospective State of the Organic Versus Inorganic Aerosol over Europe) an extended array of carbonaceous species including elemental carbon (EC), water insoluble organic carbon (WinOC) as well as dissolved organic carbon (DOC) were made along an Mt Blanc (French Alps) ice core. Although made on discrete summer ice samples this pioneering study stimulates further studies. Indeed, the EC ice record revealed an outstanding increase after World War II in summer. The reconstructionof past changes of OC (organic carbon) in ice is a challenge since only the WinOC fraction is measured by filtering the melted ice samples, and conversely, the DOC content of ice accounts for WSOC aerosol fraction as well as water-soluble organic gases. In spite of these difficulties, we demonstrated that the DOC ice record together with the ones of light carboxylates andWinOC allow reconstructing past OC (WinOC plus WSOC) changes with a rather good degree of confidence. With the aim to increase the reliability of the preceding long-term ice core trends of organics (only a few selected summer samples were studied in CARBOSOL) a new ice core was extracted at Mt Blanc at the end of the CARBOSOL project. With this respect it is here propose to use this new ice core to extract the detailed long-term trend of DOC, WinOC and EC for summer and winter through collaborative efforts between French and Portuguese scientists. A low level DOC analyzer able to reach the low level of winter samples was successfully developed at LGGE. Only the thermo-optical method deployed by Prof C. Pio would permit to reach low winter level and to satisfactorily separate the two insoluble (OC and EC) fractions. These data will give an overall picture of aerosol (load and composition) over Europe since the beginning of the 20th century. That represents key inputs needed to address the role of carbonaceous aerosol in forcing the climate.