Rapid shift in methane carbon isotopes suggests microbial emissions drove record high atmospheric methane growth in 2020-2022.

The growth rate of the atmospheric abundance of methane (CH) reached a record high of 15.4 ppb yr between 2020 and 2022, but the mechanisms driving the accelerated CH growth have so far been unclear. In this work, we use measurements of the C:C ratio of CH (expressed as C) from NOAA's Global Greenhouse Gas Reference Network and a box model to investigate potential drivers for the rapid CH growth.

Preventing drift of oxygen isotopes of CO-in-air stored in glass sample flasks: new insights and recommendations.

It is known that the oxygen isotope composition of CO-in-air, when stored over longer time periods in glass sample flasks, tends to drift to more negative values while the carbon isotope composition remains stable. The exact mechanisms behind this drift were still unclear. New experimental results reveal that water already inside the flasks during sampling plays a major role in the drift of the oxygen isotopes.

Combined -omics framework reveals how ant symbionts benefit the Neotropical ant-plant at different levels.

Ant-plant defensive mutualism is a widely studied phenomenon, where ants protect their host plants (myrmecophytes) against herbivores in return for the provision of nesting sites and food. However, few studies addressed the influence of ant colonization and herbivory on the plant's metabolism. We chose the Amazonian plant , living in association with cf.

Isotopically characterised N O reference materials for use as community standards.

Rationale: Information on the isotopic composition of nitrous oxide (N O) at natural abundance supports the identification of its source and sink processes. In recent years, a number of mass spectrometric and laser spectroscopic techniques have been developed and are increasingly used by the research community. Advances in this active research area, however, critically depend on the availability of suitable N O isotope Reference Materials (RMs).

USGS44, a new high-purity calcium carbonate reference material for δ C measurements.

Rationale: The stable carbon isotopic (δ C) reference material (RM) LSVEC Li CO has been found to be unsuitable for δ C standardization work because its δ C value increases with exposure to atmospheric CO . A new CaCO RM, USGS44, has been prepared to alleviate this situation.

Methods: USGS44 was prepared from 8 kg of Merck high-purity CaCO .

Methyl sulfates as methoxy isotopic reference materials for δ C and δ H measurements.

Rationale: Stable hydrogen and carbon isotope ratios of methoxy groups (OCH ) of plant organic matter have many potential applications in biogeochemical, atmospheric and food research. So far, most of the analyses of plant methoxy groups by isotope ratio mass spectrometry have employed liquid iodomethane (CH I) as the reference material to normalise stable isotope measurements of these moieties to isotope-δ scales. However, comparisons of measurements of stable hydrogen and carbon isotopes of plant methoxy groups are still hindered by the lack of suitable reference materials.