We describe a continuous-flow analysis (CFA) method to measure Δ¹⁷O by laser spectroscopy, and we show that centimeter-scale information can be measured reliably in ice cores by this method. We present seasonally resolved Δ¹⁷O data from Greenland and demonstrate that the measurement precision is not reduced by the CFA process. Our results encourage the development and use of CFA methods for Δ¹⁷O, and they identify calibration strategies as a target for method improvement.

A high-resolution infrared hygrometer (FIRH) was adapted to measure humidity and its rapid fluctuations in turbulence inside a moist-air wind tunnel LACIS-T where two air streams of different temperature and humidity are mixed. The measurement was achieved from outside the tunnel through its glass windows and provided an agreement with a reference dew-point hygrometer placed inside. The characterization of humidity complements previous investigations of velocity and temperature fields.

Dual thermistor radiosonde (DTR) comprising two (white and black) sensors with different emissivities was developed to correct the effects of solar radiation on temperature sensors based on in situ radiation measurements. All components contributing to the uncertainty of the radiation measurement and correction are analysed. The DTR methodology improves the accuracy of temperature measurement in the upper air within the framework of the traceability to the International System of Units.

Heating by solar radiation is the dominant error source for daytime temperature measurements by radiosondes. This paper describes a new laboratory setup (SISTER) to characterise this radiation error for pressures and ventilation speeds that are typical for the conditions between the surface and 35 km altitude. This characterisation is the basis for the radiation correction that is applied in the GRUAN data processing for the RS41 radiosonde. The GRUAN data product is compared to that of Vaisala.

A model was developed to quantitatively describe the dynamics, in terms of vapor-phase water concentration and isotope ratios, of nanoliter-droplet evaporation at the end of a syringe needle. Such a low humidity generator can be used to calibrate laser-based water isotope analyzers, e.g., in Antarctica. We show that modeling of experimental data constrains isotope fractionation factors and the evaporation rate to physically realistic values in good agreement with available literature values.