Fig. 2

Site location. (a) Location of Amsterdam Island (AMS) in the southern Indian Ocean. The island, only inhabited with approximately 20 overwintering crew members, is supplied four times a year by RV Marion Dufresne II (in April, August, November, and December) departing from Reunion Island (RUN). The ship also resupplies research stations located on Crozet (CRO) and Kerguelen (KER) islands, also part of the French Southern and Antarctic Lands. Most of the scientific instrumentation is located at the Pointe Bénédicte observatory, 2 km upwind from the Martin-de-Viviès main research station. (b) Panoramic view of the island. (c) Wet only collector with RV Marion Dufresne II in the background. (d) Interior of the Pointe Bénédicte observatory with two Tekran instruments for active/continuous measurements of GEM. (e) MerPAS systems for passive/discrete measurements of GEM. (f) Panoramic view of the Pointe Bénédicte observatory. (g) Rooftop sampling platform for atmospheric mercury measurements.