Group Lehmann at ASLO Aquatic Science Meeting 2023

Fieldwork in Hornsund, Svalbard, Norway, May 2022

In Mai 2022, Dr. Jakob Zopfi (Uni Basel) and colleagues from the Polish Academy of Sciences stayed at the Polish Polar Station at Hornsund (Spitzbergen, Norway) to explore greenhouse gas (GHG) formation and emissions from high Arctic lakes. After drilling trough 1.7 m of solid ice, water samples were collected to characterize the chemistry and microbiology at different depths in the lake. Moreover, sensor chains were installed to monitor continuously various physical and chemical parameters under the ice, during ice cover melting, and during the upcoming summer season. The ultimate goal is to quantify the fluxes of the greenhouse gases(GHG), carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), into the atmosphere or from the atmosphere into the lake. This research will reveal whether the new ecosystems that form after the disappearance of glaciers, such as lakes, creeks, and wetlands, will represent potential sinks or additional sources of GHG.

Fieldwork on Lake Nylandssjön, Sweden, 22 March 2022

Jules Millet and Anja Studer from the Biogeochemistry group went to visit their collaborators Christian Bigler and Johan Rydberg at Umeå University, Sweden, during March 2022. Together, they went field sampling on Lake Nylandssjön, which is a small, dimictic, mesotrophic lake in Northern Sweden. They collected water and plankton samples through the ice, but most importantly, they retrieved sediment cores from the lake bottom. Since about 100 years, the sediment of Lake Nylandssjön preserves varves of excellent quality, which can be subsampled at an annual resolution when retrieved by freeze-coring. The Lake Nylandssjön sediments will allow us to study diagenetic alteration of organic nitrogen contained within diatom frustules on decadal timescales.

FS 2022 33155-01 Marine Biology and Biogeochemistry

We found a new home for our Marine Biology and Biogeochemistry course: Island of Giglio

HS 2020 39453-01 Methods in Environmental Geosciences: Principles in Aquatic Biogeochemistry

An exciting laboratory practical is also possible under strict corona conditions ......

FS 2019 33155-01 Marine Biology and Biogeochemistry

An exciting two-week excursion on Elba with support from Dr. Miriam Weber, Hydra Marine Science.

HS 2018 39453-01 Methods in Environmental Geosciences: Principles in Aquatic Biogeochemistry

During the basic lab training in aquatic biogeochemistry, Bachelor students were sampling water all around Basel, like the Birsig, Wiese and Rhein. The main goals are to get a better understanding of analytical methods in the lab as well as to investigate the water quality in and around Basel.

Fun & Sciences - Zschokke Haus Engelberg

In February, we spent two exciting days in the Swiss Alps near Engelberg, where everyone presented his/her projects. Great scientific exchange, and a lot of fun in the snow. Zschokke Haus, we will come again!

Winter Sampling Cadagno (18/19 April, 2018)

Lake Cadagno is a small meromictic lake in the southern Swiss Alps at 1921 m altitude. It is a well-established model system for an Early Earth Ocean. The biogeochemical processes operating during the short summer months have been investigated in great detail. But the lake is difficult to access in winter and therefore not much is known about the physical and chemical conditions under the ice cover. Even less is known about the microorganisms dwelling in the dark, cold water and the biogeochemical processes they are driving. A team from the Biogeochemistry Group, Jessica, Paul, Maciej and Jakob, set out to explore the wintertime microbial communities and to determine how much of the greenhouse gas methane is produced and trapped under the ice cover.

Sea- going expedition to the tropical pacific with the SCRIPPS vessel R/V Sally Ride

Post doc, Claudia Frey, participated in a 6 weeks long cruise lead by PI Prof. Bess Ward to the Tropical pacific. Starting off in San Diego, U.S.A. we took over 6000 water samples within 6 weeks on our way to Manzanillo, Mexico.
The goal was to resolve exactly where and how much nitrous oxide is produced and consumed by ocean microbes. For that we analysed the level of nitrogen and oxygen at different depths. Knowing the origins and sinks of the powerful greenhouse gas, N2O has significant implications for modeling global warming. Microbes produce more than half of the planet’s nitrous oxide, which is not only contributing to climate change but also destroying our protective ozone layer.
The pictures not just give an impression of how we get the water samples and how we process them, but also on the beauty of the sea.

FS 2017 33155-01 Marine Biology and Biogeochemistry

A joint course of the Zoology and the Biogeochemistry programs at the Departement of Environmental Sciences in Spring semester 2017

The Biogeochem Group

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