Cavity Ring-Down Spectroscopy Performance and Procedures for High-Throughput O and H Measurement in Water Using "Express" Mode.

Cavity ring-down spectroscopy (CRDS) is rapidly becoming an invaluable tool to measure hydrogen (δ²H) and oxygen (δO) isotopic compositions in water, yet the long-term accuracy and precision of this technique remain relatively underreported. Here, we critically evaluate one-year performance of CRDS δ²H and δO measurements at ETH Zurich, focusing on high throughput (~200 samples per week) while maintaining required precision and accuracy for diverse scientific investigations. We detail a comprehensive methodological and calibration strategy to optimize CRDS reliability for continuous, high-throughput analysis using Picarro's "Express" mode, an area not extensively explored previously.

Low NO and variable CH fluxes from tropical forest soils of the Congo Basin.

Globally, tropical forests are assumed to be an important source of atmospheric nitrous oxide (NO) and sink for methane (CH). Yet, although the Congo Basin comprises the second largest tropical forest and is considered the most pristine large basin left on Earth, in situ NO and CH flux measurements are scarce. Here, we provide multi-year data derived from on-ground soil flux (n = 1558) and riverine dissolved gas concentration (n = 332) measurements spanning montane, swamp, and lowland forests.

In-depth analysis of NO fluxes in tropical forest soils of the Congo Basin combining isotope and functional gene analysis.

Primary tropical forests generally exhibit large gaseous nitrogen (N) losses, occurring as nitric oxide (NO), nitrous oxide (NO) or elemental nitrogen (N). The release of NO is of particular concern due to its high global warming potential and destruction of stratospheric ozone. Tropical forest soils are predicted to be among the largest natural sources of NO; however, despite being the world's second-largest rainforest, measurements of gaseous N-losses from forest soils of the Congo Basin are scarce.