A year‐long record of size‐segregated aerosol composition at Halley, Antarctica

Abstract

[1] Size-segregated aerosol samples were collected with a cascade impactor at 2 week intervals for a year at the research station Halley, situated near the coast in the Weddell Sea region of Antarctica. Sea salt is a major component of aerosol throughout the year, and we estimate that at least 60% of the total sea salt arriving at Halley is from brine and frost flowers on the sea ice surface rather than open water. Chloride in sea-salt particles is depleted relative to sodium in summer, consistent with loss of HCl as seasalt particles react with gaseous acidic species, but is enhanced in large particles in winter because of fractionation occurring during the production of new sea ice. Nonsea-salt sulphate peaks in the summer, with the majority being in small particles indicative of a gas phase origin. The distribution of methane sulphonic acid closely follows that of non-sea-salt sulphate. In the winter, non-sea-salt sulphate is frequently negative, especially on stages collecting large particle sizes, consistent with the source of sea salt during the winter being predominantly the sea ice surface rather than open water. Nitrate peaks in the spring and summer and shows some association with seasalt particles.

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

“…Therefore, using the total measured atmospheric nitrate as gaseous HNO 3 for constraining the models might lead to an overestimate of ] in snow at Dome C, especially in early summer. At the coastal site of Halley, there is a strong influence from sea salt aerosol with corresponding larger concentration of nitrate-containing aerosol, especially in spring time such that the monthly mean p − NO − 3 mixing ratio is ∼ 4.6 pptv (Rankin et al, 2003;Jones et al, 2011). Therefore, neglecting the dry deposition of nitrate aerosols might underestimate the concentration of nitrate in the surface snow in spring time.…”

DMS and MSA measurements in the Antarctic Boundary Layer: impact of BrO on MSA production

“…The relationship between DMS and propane was verified in laboratory experiments both before and after the CHABLIS campaign. Main precision errors in the measurement of DMS and propane arise from peak integration (Read et al, 2007).…”

“…DMS was measured every hour using a gas chromatograph with flame ionisation detection (Read et al, 2007). The detection limit for this species was 5 pptV and the uncertainty on the measurement <5 pptV.…”

Seasonal variations and vertical features of aerosol particles in the Antarctic troposphere

“…Aerosol measurements in Antarctic regions have been made at coastal stations: Syowa (69 • 00 S and 39 • 35 E) (Ito et al, 1989(Ito et al, , 1993Osada et al, 1998;Hara et al, 2004Hara et al, , 2010, Halley (75 • 36 S, 26 • 19 W) Rankin and Wolff, 2003), Neumayer (70 • 39 S, 08 • 15 W) Minikin et al, 1998), Dumont d'Urville (66 • 40 S; 140 • 00 E) , and Mawson (67 • 36 S 62 • 52 E) (Savoie et al, 1992(Savoie et al, , 1993. They have also been made at inland stations: Dome-F (77 • 19 S 39 • 42 E) , Kohnen (75 • 00 S 00 • 04 E) (Weller et al, 2007), Concordia (75 • S, 123 • E) (Jourdain et al, 2008), and at the South Pole (Amundsen Scott) (90 • S) (Bodhaine, 1995).…”