Chemistry of the Antarctic Boundary Layer and the Interface with Snow: an overview of the CHABLIS campaign

Abstract

Abstract. CHABLIS (Chemistry of the Antarctic BoundaryLayer and the Interface with Snow) was a collaborative UK research project aimed at probing the detailed chemistry of the Antarctic boundary layer and the exchange of trace gases at the snow surface. The centre-piece to CHABLIS was the measurement campaign, conducted at the British Antarctic Survey station, Halley, in coastal Antarctica, from January 2004 through to February 2005. The campaign measurements covered an extremely wide range of species allowing investigations to be carried out within the broad context of boundary layer chemistry. Here we present an overview of the CHABLIS campaign. We provide details of the measurement location and introduce the Clean Air Sector Laboratory (CASLab) where the majority of the instruments were housed. We describe the meteorological conditions experienced during the campaign and present supporting chemical data, both of which provide a context within which to view the campaign results. Finally we provide a brief sumCorrespondence to: A. E. Jones (a.jones@bas.ac.uk) mary of highlights from the measurement campaign. Unexpectedly high halogen concentrations profoundly affect the chemistry of many species at Halley throughout the sunlit months, with a secondary role played by emissions from the snowpack. This overarching role for halogens in coastal Antarctic boundary layer chemistry was completely unanticipated, and the results have led to a step-change in our thinking and understanding.

Modelling the physical multiphase interactions of HNO<sub>3</sub> between snow and air on the Antarctic Plateau (Dome C) and coast (Halley)

“…Meteorological and chemical data were collected at Halley under the CHABLIS (Chemistry of the Antarctic Boundary Layer and the Interface with Snow) campaign at the Clean Air Sector Laboratory (CASLab; details in Jones et al, 2008Jones et al, , 2011. The site description and data are given in details elsewhere ; a brief description is given in the following.…”

Characterising terrestrial influences on Antarctic air masses using Radon-222 measurements at King George Island

“…Crawford et al, 2001;Davis et al, 2001Davis et al, , 2004Oncley et al 2004;Jones et al, 2008). Furthermore, the precise role that global circulation patterns play in the seasonal cycles of some trace species in Antarctica continues to challenge the global modelling community (Zhang et al, 2011(Zhang et al, , 2008Josse et al, 2004;Taguchi et al, 2002;Heinmann et al, 1990).…”

“…Jones et al, 2008;Helmig et al, 2007;Illic et al, 2005;Wolff et al, 1998;Pereira, 1990), and interpretation of trace impurities in Antarctic ice cores has become a popular window through which to view past global climate. To do this, however, requires a solid understanding of the transport and fate of trace elements to this region.…”

“…Steig and Orsi, 2013;Heffernan, 2012;Pereira et al, 2006), there is growing interest in quantifying the magnitude and source regions of pollutants affecting this pristine region (e.g. Jones et al, 2008;Pereira et al, 2004;Jacobi et al, 2000;Berresheim and Eisele, 1998). In turn, anthropogenically driven changes to Antarctic climate and ecosystems have the potential to feedback to the global climate system, due to the significant role that Antarctica plays in largescale atmospheric and oceanic circulation patterns.…”

HO<sub>2</sub>NO<sub>2</sub> and HNO<sub>3</sub> in the coastal Antarctic winter night: a "lab-in-the-field" experiment

“…It was installed in the Clean Air Sector Laboratory (CASLab), which is located roughly 1 km from the main Halley station, and in a sector that rarely receives air from the base (Jones et al, 2008). The CIMS inlet extended ∼ 20 cm above the roof of CASLab, at a height roughly 5 m above the surrounding snowpack.…”