Atmospheric Hg speciation
OMP Atmospheric chemistry platform
Substantial lab modifications were made in 2010 to modify the atmospheric chemistry platform. The lab is now air-conditioned (18 +/- 2oC), insulated, has UPS clean current and battery back-up. For the Hg sensors we installed a 50m long Teflon line that brings in high purity argon gas from high pressure bottles. A dedicated bottle repository was installed at the La Mongie departure station of the cable car, where gas is delivered once per year by our supplier.
Tekran Inc. Hg Speciation system (2537B/1130/1135)
This well-known commercial Hg speciation system is installed indoors at the Pic du Midi in order to avoid technical issues during the harsh winter period (ice riming and storms). The system operationally separates 3 different atmospheric Hg species: gaseous elemental Hg (GEM), gaseous oxidized Hg (GOM, such as HgCl2, HgB2, HgO), and particulate bound Hg (PBM). GEM is measured at a 5 min frequency, while GOM and PBM are measured at a 2h frequency. Our observations are accessible through GMOS (www.gmos.eu).
Tekran Teflon heated sampling manifold
The teflon coated manifold allows trace metal clean air sampling at a flow rate of 100 L/min. The manifold has 6 entrance ports that can provide air to different instruments. Currently we use 1 port for the Tekran Hg speciation system and 1-3 ports for manual Hg isotope sampling.
CASCC-2 cloud water sampler
The CASCC-2 was constructed by Prof. Jeffrey Collett’s lab at Colorado State University ( http://collett.atmos.colostate.edu/instrumentation2.html) and is operated at the Pic du Midi during Spring, Summer and Fall. The trace metal clean instrument operates at 6 m3/min and provides approx. 10 mL/min of cloud water under typical in-cloud conditions.
Tisch high volume sampler
Our Tisch sampler is equipped with a PM2.5 size cut-off and operated at the Pic du Midi during Spring, Summer and Fall. It is currently used to provide enough particles for the Hg stable isotope analysis of particulate bound Hg.