I invested most of the first year in the GMOS-train in the data analysis of atmospheric mercury measured at two southern hemisphere sites: Chacaltaya mountain in the tropical Bolivian Andes and Maïdo observatory in the tropical Indian Ocean.

I was very lucky that the collaboration with my supervisors and colleagues worked smoothly and pleasantly, even in times where in-person discussions and meetings were in short supply. In this productive work environment, I managed to get the first paper on atmospheric mercury at Chacaltaya published (“Seasonal patterns of atmospheric mercury in tropical South America as inferred by a continuous total gaseous mercury record at Chacaltaya station (5240 m) in Bolivia”). A second article about atmospheric mercury at Chacaltaya, this time focused on the impact of the 2015-2016 El Niño, is nearly ready to be submitted to a journal.

I also had time to advance in the Maïdo dataset, which appears to be very “rich”: alongside continuously sampled atmospheric mercury (Hg0), other trace gases (such as ozone and SO2) as well as volatile organic compounds were also measured at Maïdo. One striking feature appearing in Maïdo Hg0 observations is that diel cycles are very regular, with higher Hg0 during daytime and significantly lower Hg0 during nighttime. I hope to be able to extract information about mercury dynamics in the tropical Indian Ocean by looking more closely at these diel cycles and by considering the behavior of auxiliary variables. While the data treatment of this dataset is still in the early stages, the first results were already presented at the Goldschmidt2021 conference.

Even though most of my work involves reading articles, discussing with colleagues, or coding on my computer, I also had the opportunity of a more hands-on experience involving mercury: During a secondment to the GET in Toulouse, I got to work in the chemical analysis of oxidized mercury samples.

By Alkuin Koenig (ESR 1)