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Sat, Feb

Rare Traces of a Volatile Gas

Typography

Nitrogen oxides — i.e. nitrogen compounds with varying amounts of oxygen — have a very bad reputation. They are produced among other things by burning fossil fuels. In regions with heavy traffic and a lot of industry, they occur in high concentrations and are made responsible for a large number of diseases of the respiratory system. However, nitrogen oxides also occur in nature. There they play an important role in the nitrogen cycle, which ensures that nitrogen, essential for life, is available in forms that the organisms can process.

Nitrogen oxides — i.e. nitrogen compounds with varying amounts of oxygen — have a very bad reputation. They are produced among other things by burning fossil fuels. In regions with heavy traffic and a lot of industry, they occur in high concentrations and are made responsible for a large number of diseases of the respiratory system. However, nitrogen oxides also occur in nature. There they play an important role in the nitrogen cycle, which ensures that nitrogen, essential for life, is available in forms that the organisms can process.

One of these nitrogen oxides is nitrogen monoxide (NO). Where it is produced in nature and in which quantities is hardly known. It is very volatile and reacts quickly with other substances. Therefore, NO is difficult to measure, especially in the world's largest ecosystem, the ocean. In the past few years, researchers at the GEOMAR Helmholtz Centre for Ocean Research Kiel have developed a new measurement method and used them during an expedition of the Collaborative Research Center (SFB) 754 “Climate-Biogeochemical Interactions in the Tropical Ocean” in the eastern tropical South Pacific Ocean. Now, they have published the first results in the international journal Deep-Sea Research Part II. “We have been able to demonstrate a clear link between low oxygen concentrations and the production of NO,” says Hannah Lutterbeck, first author of the study.

The new NO-data set is the first since 30 years. “There have been some attempts to measure oceanic NO in the 1980s, but the procedure was extremely complex and resulted in comparatively few data points,” explains co-author Prof. Dr. Hermann Bange from GEOMAR. Since then, research has hardly dealt with the topic of NO in seawater — until Hannah Lutterbeck has taken up the topic again for her PhD thesis.

Read more at Helmholtz Centre for Ocean Research Kiel (GEOMAR)

Image: RV MTEOR in the southeast Pacific Ocean. During an expedition of the SFB754 in this region scientists were able to obtain the first NO-data set in 30 years. Photo: Hermann Bange/GEOMAR (CC BY 4.0)