Tethered balloon observations are highly valuable for aerosol studies in the lowest part of the atmosphere. This study presents a newly developed platform called CAMP with four aerosol instruments for balloon-borne measurements in the Arctic. Laboratory characterizations and evaluations of the instruments and results of a first field deployment are shown. A case study highlights CAMP's capabilities and the importance of airborne aerosol studies for interpretation of ground-based observations.

We used methods from the field of artificial intelligence to train an algorithm to estimate rain from satellite observations. In contrast to other methods, our algorithm not only estimates rain, but also the uncertainty of the estimate. Using independent measurements from rain gauges, we show that our method performs better than currently available methods and that the provided uncertainty estimates are reliable. Our method makes satellite-based measurements of rain more accurate and reliable.

In this study, we demonstrate that selective online measurements of cycloalkanes can be achieved using proton transfer reaction time-of-flight mass spectrometry with NO⁺ chemical ionization (NO⁺ PTR-ToF-MS), with fast response and low detection limits. Applications of this method in both urban air and emission sources will be shown.

Four upper tropospheric humidity (UTH) datasets derived from satellite microwave and infrared sounders are evaluated to assess their consistency as part of the activities for the Global Energy and Water Exchanges (GEWEX) water vapor assessment project. The study shows that the four datasets are consistent in the interannual temporal and spatial variability of the tropics. However, differences are found in the magnitudes of the anomalies and in the changing rates during the common period.

Black carbon (BC) is often assumed to be spherically shaped, causing uncertainties in its optical properties when modelled. This study investigates different modelling techniques for the optical properties of BC by comparing them to laboratory measurements. We provide experimental support for emphasizing the use of appropriate size representation (polydisperse size method) and morphological representation (aggregate morphology) for optical modelling and parameterization scheme development of BC.

Errors of profiles of temperature and mixing ratios retrieved from spectra recorded with the Michelson Interferometer for Passive Atmospheric Sounding are estimated. All known and quantified sources of uncertainty are considered. Some ongoing uncertaities contribute to both the random and to the systematic errors. In some cases, one source of uncertainty propagates onto the error budget via multiple pathways. Problems arise when the correlations of errors to be propagated are unknown.

N₂O₅ is an important reservoir of atmospheric nitrogen, on whose interface reaction ambient particles can largely influence the fate of nitrogen oxides and air quality. In this study, we develop an approach to enable the reactions of N₂O₅ on ambient particles directly in a tube reactor, deriving the reaction rates with high accuracy by means of a chemistry model. Its successful application helps complement the data scarcity and to fill the knowledge gap between laboratory and field results.

A new formula of the complete data fusion that, differently from the original one, does not contain matrices that can be singular is discussed. We show that the new formula is a generalization of the original one and analytically and numerically, using a real IASI ozone measurement, derive the errors made with the old formula when the generalized inverse of singular matrices is used. An operational version of the new formula that includes interpolation and coincidence errors is also provided.

In August 2018, the first wind lidar Aeolus was launched into space and has since then been providing data of the global wind field. The primary goal of Aeolus was the improvement of numerical weather prediction. To verify the quality of Aeolus wind data, DLR performed four airborne validation campaigns with two wind lidar systems. In this paper, we report on results from the two later campaigns, performed in Iceland and the tropics.

Observations of phase speed and direction spectra as well as zonal mean net gravity wave momentum flux are required to understand how gravity waves reach the mesosphere–lower thermosphere and how they there interact with background flow. To this end we propose flying two CubeSats, each deploying a spatial heterodyne spectrometer for limb observation of the airglow. End-to-end simulations demonstrate that individual gravity waves are retrieved faithfully for the expected instrument performance.

Water vapor concentration in the atmosphere at small scales (< 6 km) is considered. The measurements show Gaussian random field behavior following Kolmogorov's theory of turbulence two-thirds law. These properties can be useful when estimating the water vapor variability within a given observed satellite scene or when different water vapor measurements have to be merged consistently.

Vertical profiles of latent heating are derived from GOES-16 to be used in convective initialization. They are compared with other latent heating products derived from NEXRAD and GPM satellites, and the results show that their values are very similar to the radar-derived products. Finally, using latent heating derived from GOES-16 for convective initialization shows improvements in precipitation forecasts, which are comparable to the results using latent heating derived from NEXRAD.

We introduce the aerosolomics database and apply it to particulate matter samples. Nine VOCs were oxidized under various conditions in an oxidation flow reactor, and the formed SOA was measured using liquid chromatography mass spectrometry. With the database, an unambiguous top-down attribution of atmospheric oxidation products to their parent VOCs is now possible. Combining the database with hierarchical clustering enables a better understanding of sources, formation, and partitioning of SOA.

This work developed a multi-band–multi-pass–multi-comparison-date Sentinel-2 methane retrieval algorithm, and the method was calibrated by data from a controlled release test. To our knowledge, this is the first study that validates the performance of a Sentinel-2 methane detection algorithm by calibration with a ground-truth testing. It illustrates the potential for additional validation with systematic future experiments wherein algorithms can be tuned to meet different detection expectations.

We use numerical models to study field measurements of sea spray aerosol particles and conclude that both the atmospheric state and the methods of instrument sampling are causes for the variation in the production rate of aerosol particles: a critical metric to learn the aerosol's effect on processes like cloud physics and radiation. This work helps field observers improve their experimental design and interpretation of measurements because of turbulence in the atmosphere.