Global Navigation Satellite System radio occultation data help monitor climate and weather prediction but are affected by residual ionospheric errors (RIEs). A new excess-phase-gradient method detects and corrects RIEs, showing both positive and negative values, varying by latitude, time, and solar activity. Tests show that RIE impacts polar stratosphere temperatures in models, with differences up to 3–4 K. This highlights the need for RIE correction to improve the accuracy of data assimilation.

This article introduces an experimental system for rapidly acquiring trace gas profiles using multi-channel spectroscopy, significantly enhancing the time resolution of spectral collection. The fast synchronous multi-axis differential optical absorption spectroscopy (FS MAX-DOAS) successfully obtains gas profiles. This work can also be integrated with mobile platforms for navigational observation research, which is crucial for making mobile MAX-DOAS profile measurements.

Significant improvements have been made to the instruments used to measure OH reactivity, which is equivalent to the sum of air pollutant concentrations. Accurate and precise measurements with a high time resolution have been achieved, allowing use on aircraft, as demonstrated during flights in the USA.

We present a method for the determination of greenhouse gases (CH₄, CO_2, N₂O) using a chromatographic system with a barrier ion discharge detector (BID) and a Carboxen 1010 capillary column. The system omits the need for an electron capture detector (ECD) containing radiogenic components for N₂O analysis and a flame ionisation detector (FID) with a methaniser for CO₂ samples. This simplification reduces analytical costs, facilitates instrument maintenance and improves measurement robustness.

New low-cost, off-the-shelf Global Navigation Satellite System (GNSS) receivers enable the estimation of zonal ionospheric irregularity drifts using the scintillation spaced-receiver technique, previously tested only with commercial GNSS receivers. Despite their low C/No resolution (1 dB-Hz), we demonstrate that the recorded raw data can be used to estimate irregularity drifts. Further, our observations are consistent with the behavior of an empirical model of the thermospheric winds (HMW14).

Temperature is essential to understanding the thermosphere. Most temperature measurements have been indirect or had large uncertainties, especially in the lower-middle thermosphere, where data are rarely available. Since October 2018, NASA’s GOLD mission has produced disk images of neutral temperatures near 160 km at locations over the Americas and Atlantic Ocean. This paper discusses both temperature retrieval techniques and issues in interpreting GOLD’s images of thermospheric temperatures.

We find that small particles suspended in the air (aerosols) affect the satellite observations of carbon dioxide (CO₂) made by the Orbiting Carbon Observatory-2 satellite instrument. Satellite estimates of CO₂ appear to be too high for clean areas and too low for polluted areas. Our results show that CO₂ and aerosols are often co-emitted, and this is partly masked out in the current retrievals. Correctly accounting for the aerosol effect is important for CO₂ emission estimates by satellites.

Polarimetric radio occultations (PROs) use polarized radio signals from satellites to detect moisture and precipitation in Earth's atmosphere. By applying nonlinear regression and k-means cluster analysis to over 2 years of PRO and non-PRO data, this study shows how deviations from a refractivity model relate to vertical profiles of water vapor pressure (moisture) and that differences between components of PRO signals correlate directly with vertical profiles of water path (precipitation).

We tested different cylinders and methods to create standard gas mixtures of acetonitrile, a chemical important for understanding air quality and climate change. We found making accurate mixtures at very low levels challenging due to the gas sticking to cylinder walls. However, we successfully created stable mixtures at higher levels. These can be used as reliable standards for global air monitoring. More research is needed to develop methods for making accurate mixtures at lower levels.

Satellite remote sensing retrievals of cloud droplet size are used to understand clouds and their interactions with aerosols and radiation but require many simplifying assumptions. Evaluation of these retrievals is typically done by comparing against direct measurements of droplets from airborne cloud probes. This paper details an evaluation of proxy airborne remote sensing droplet size retrievals against several cloud probes and explores the impact of key assumptions on retrieval agreement.

Proton-transfer-reaction mass spectrometry (PTR-MS) is widely used for the measurement of volatile organic compounds (VOCs) both indoors and outdoors. An analytical challenge for PTR-MS measurements is the formation of unintended measurement interferences, product ion distributions (PIDs), that may appear in the data as VOCs of interest. We developed a method for quantifying PID formation and use interlaboratory comparison data to put quantitative constraints on PID formation.

Temperature (T) and wind profiles were measured by a Doppler wind lidar and a microwave radiometer in Meiringen in a medium-sized Alpine valley. Ground-based T inversions and thermal winds were studied during the 10 months of the campaign. The comparison between the observations and the COSMO-1E model provides good model performance for monthly climatologies. T inversions are however frequently missed, and important differences for particular cases are found, especially for foehn events.

Airborne particles are crucial in environmental and health studies, requiring precise sampling for accurate characterisation. Our study examines the optimal sampling time for the TSI Nanometer Aerosol Sampler 3089 at different input concentrations. Aerosols from low-, medium-, and high-concentration environments were sampled over 1, 3, and 6 h. A linear relationship was observed using a regression model between the deposition densities and the product of input concentration and sampling time.