Direct Gravimetric Measurements of the Mass of the Antarctic Aerosol Collected by High Volume Sampler: PM10 Summer Seasonal Variation at Terra Nova Bay

• Published in: Annali di Chimica
• Main Authors: Truzzi, Cristina, Lambertucci, Luca, Illuminati, Silvia, Annibaldi, Anna, Scarponi, Giuseppe
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2005
• Subjects: Antarc*; Antarctic; Antarctic Peninsula; ice core; Ice Shelf; King George Island; Ronne Ice Shelf; South pole
• Online Access: http://dx.doi.org/10.1002/adic.200590099; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fadic.200590099; https://onlinelibrary.wiley.com/doi/pdf/10.1002/adic.200590099

Abstract An on‐site procedure was set up for direct gravimetric measurement of the mass of aerosol collected using high volume impactors (aerodynamic size cut point of 10 μm, PM10); this knowledge has hitherto been unavailable. Using a computerized microbalance in a clean chemistry laboratory, under controlled temperature (±0.5 °C) and relative humidity (±1 %), continuous, long time filter mass measurements (hours) were carried out before and after exposure, after a 48 h minimun equilibration at the laboratory conditions. The effect of the electrostatic charge was exhausted in 30‐60 min, after which stable measurements were obtained. Measurements of filters exposed for 7‐11 days (1.13 m 3 min −1 ) in a coastal site near Terra Nova Bay (December 2000 – February 2001), gave results for aerosol mass in the order of 10‐20 mg (SD ∼2 mg), corresponding to atmospheric concentrations of 0.52‐1.27 μg m −3 . Data show a seasonal behaviour in the PM10 content with an increase during December – early January, followed by a net decrease. The above results compare well with estimates obtained from proxy data for the Antarctic Peninsula (0.30 μg m −3 ), the Ronne Ice Shelf (1.49 μg m −3 ), and the South Pole (0.18 μg m −3 , summer 1974‐1975, and 0.37 μg m −3 , average summer seasons 1975‐ 1976 and 1977‐1978), and from direct gravimetric measurements recently obtained from medium volume samplers at McMurdo station (downwind 3.39 μg m −3 , upwind 4.15 μg m −3 ) and at King George Island (2.5 μg m −3 , summer, particle diameter <20 μm). This finding opens the way to the direct measurement of the chemical composition of the Antarctic aerosol and, in turn, to a better knowledge of the snow/air relationships as required for the reconstruction of the chemical composition of past atmospheres from deep ice core data.