Clumped-isotope signals obtained through gas source mass spectrometry are typically small and require pressure baseline corrections. While such corrections have been developed for square-shaped peaks, we present an approach for correcting peaks with complex shapes. Our method is demonstrated using oxygen clumped isotopes measured in pure oxygen, where the peak tops are linearly increasing and/or negatively curved.

Continuous vertical profiles and discrete stratospheric samples of carbonyl sulfide (COS) were collected deploying the balloon-borne AirCore, LISA and BigLISA samplers and measured on a Quantum Cascade Laser Spectrometer (QCLS). Our measurements show good accordance with previous COS observations. Moreover, laboratory tests of ozone (O₃) scrubbers proved squalene to remove O₃ very efficiently without biasing the measurements of other trace gases.

We observed the persistent, man-made trifluoroacetate (TFA) in precipitation and surface waters. Atmospheric simulations attributed TFA to precursor gases in the atmosphere. Although recently increasing concentrations could be followed, gaps in the budget indicate limited understanding of the atmospheric degradation of widely used fluorocarbons. Without additional regulation, environmental TFA concentrations are expected to rise strongly, necessitating continued monitoring and risk assessment.

A new federative chronology for five deep polar ice cores retrieves 800 000 years of past climate variations with improved accuracy. Precise ice core timescales are key to studying the mechanisms linking changes in the Earth’s orbit to the diverse climatic responses (temperature and atmospheric greenhouse gas concentrations). To construct the chronology, new measurements from the oldest continuous ice core as well as glaciological modeling estimates were combined in a statistical model.

The southern coast of South Africa hosts some key archeological sites for the study of early human evolution. Here we present a short but high-resolution record of past changes in the hydroclimate and temperature on the southern coast of South Africa based on the study of a speleothem collected from Bloukrantz Cave. Overall, the paleoclimate indicators suggest stable temperature from 48.3 to 45.2 ka, whereas precipitation was variable, with marked short drier episodes.