Using current space-borne measurements from one spectral domain (TIR or UV), only ozone down to 3–4 km altitude may be observed with adequate vertical sensitivity. Here, we evaluate the potential of a new multispectral retrieval method that combines the information from TIR and UV measurements provided by the new-generation sensors IASI-NG and UVNS. Both are on board the upcoming EPS-SG satellite. This new IASI-NG+UVNS retrieval approach allows observations of ozone layers down to 2 km a.s.l.

A European-wide ²²²radon/²²²radon progeny comparison study has been conducted at nine measurement stations in order to determine differences between existing ²²²radon instrumentation and atmospheric data sets, respectively. Mean differences up to 45 % were found between monitors. These differences need to be taken into account if the data shall serve for quantitative regional atmospheric transport model validation.

²²²Radon is often used to parameterise atmospheric transport in the lower troposphere. It can be measured via its decay products, which are bound to aerosol. Air sampling through long tubing, which sometimes cannot be avoided at tall tower sites, may then cause severe aerosol and corresponding radon daughter activity loss. We have quantified this loss for 8.2 mm ID Decabon tubing used at European stations and provide a length-dependent correction function for this experimental setting.

Single-particle mass spectrometers (SPMSs) can determine the size and chemical composition of single particles in real time. We developed the first open-source SPMS toolkit to allow creative script-based data mining along with GUI-based visual data exploration and calibration all within a single programming environment. We believe that this software will be adopted by many in the SPMS community and improve the efficiency of knowledge discovery from these atmospherically critical data sets.

The Multi-Angle Snowflake Camera (MASC) provides high-resolution pictures of individual falling snowflakes and ice crystals. A method is proposed to automatically classify these pictures into six classes of snowflakes as well to estimate the degree of riming and to detect whether or not the particles are melting. Multinomial logistic regression is used with a manually classified reference set. The evaluation demonstrates the good and reliable performance of the proposed technique.

In-flight icing is an important aviation hazard which is still poorly understood, but consensus is that the presence of high ice water content is a necessary condition. For the European High Altitude Ice Crystals project a geostationary satellite remote-sensing mask has been developed for detection of atmospheric cloud environments where high ice water content is likely to occur. The mask performs satisfactory when compared against independent satellite ice water content measurements.

Two model systems are studied: dicarboxylic acid particles with gaseous amines and α-cedrene ozonolysis particles. Measurements by direct analysis in real-time mass spectrometry and high-resolution time-of-flight aerosol mass spectrometry show that the reaction of the amines with the acid particles is restricted to the surface layer, with an odd–even alternating pattern. Furthermore, in the α-cedrene study, DART-MS is able to differentiate isomers based on their volatility.

The microwave radiometers (MWR) on board ERS-1, ERS-2, and Envisat provide a continuous time series of brightness temperature observations between 1991 and 2012. Here we report on a new total column water vapour (TCWV) and wet tropospheric correction (WTC) dataset that builds on this time series. The dataset is publicly available under doi:10.5676/DWD_EMIR/V001.

An assessment of IIR radiances after 9.5 years of nearly continuous operation since June 2006 is presented. First, IIR is compared with similar MODIS or SEVIRI channels in various conditions. Second, clear sky measurements in each channel are compared with simulations. The first approach detects biases and/or trends, and the second approach contributes to identifying which channel deviates from the other. The analyses are based on simulations using the 4A/OP radiative transfer model.

The satellite instrument VIIRS is being used to carry on observations of the Earth made by older satellites like MODIS. Data sets created from these satellite observations depend on the quality of the satellite instruments' calibration. This paper describes a comparison between the calibration of these two sensors. MODIS is believed to be more reliable and so VIIRS is corrected to bring it in line with MODIS. These corrections are shown to improve the quality of VIIRS aerosol data.

A commercial PTR-ToF-MS has been optimized in order to allow the measurement of individual organic nitrates in the atmosphere. This has been accomplished by shifting the distribution between different ionizing analytes. The proposed approach has been proved to be appropriate for the online detection of individual alkyl nitrates and functionalized nitrates.

A new incoherent broadband cavity-enhanced absorption spectrometer for ambient NO₃ and N₂O₅ detection is developed. This new instrument is featured with a mechanically aligned non-adjustable optical mounting system. Fast setup and stable running of this N₂O₅ spectrometer were successfully achieved during recent field campaigns in China due to this new feature. In addition, a dynamic reference spectrum is used for the CEAS type of instrument by NO titration for the first time.

Two portable spectrometers, assumed to be internally precise, were taken to four different sites with (stationary) TCCON spectrometers. Biases of column averaged CO₂ and CH₄ measured among the TCCON sites were estimated experimentally. Results suggest that maximum (95 % confidence interval) bias among sites is less than what was estimated from a previous analytical error analysis.

In this study, we demonstrate a very good consistency of the SO₂ retrievals from OMI and OMPS using our state-of-the-art principal component analysis technique. Four full years of OMI and OMPS SO₂ retrievals, during 2012–2015 have been analyzed over some of the world’s most polluted regions: eastern China, Mexico, and South Africa. The consistency of retrievals between OMI and OMPS make it possible to continue the long-term global SO₂ pollution monitoring.

A MIPAS instrument was flown in 2002–2012 on the Envisat satellite and measured atmospheric composition. There exist four processors retrieving atmospheric profiles from MIPAS spectra. We performed a mathematically clean merging of 2007–2008 datasets of ozone from these four processors. The merged product was compared with ozone datasets from ACE-FTS and MLS instruments. The advantages and the shortcomings of this merged product are discussed.

Atmospheric particles affect climate, health and visibility, and a large source of these particles is secondary aerosol formation. We developed a new oxidation flow reactor for studying the secondary aerosol formation potential of rapidly changing emission sources. Using laboratory measurements, we show that this flow reactor is suitable for studying the secondary aerosol potential of, for example, light duty vehicle emissions during a transient driving cycle.

Aerosol amount and type affect the “atmospheric correction” needed to derive ocean surface chlorophyll a concentration (Chl) from satellite remote sensing and, conversely, the ocean surface representation affects aerosol retrieval products. We introduce a coupled atmosphere-surface retrieval for Multi-angle Imaging SpectroRadiometer observations over dark water aimed at improving both aerosol and Chl results. We also refine the MISR calibration, critical to achieving high-quality retrievals.

The concept of a rain event is used to obtain a parsimonious characterisation of rain events using a minimal subset of variables at macrophysical scale. A classification in five classes is obtained in a unsupervised way from this subset. Relationships between these classes of microphysical parameters of precipitation are highlighted. There are several implications especially for remote sensing in the context of weather radar applications and quantitative precipitation estimation.

The philosophy, background, and details of high-resolution urban observation network to meet the need of reducing damages caused by extreme weather phenomena such as heavy rain/snow fall, strong wind, heat/cold waves, or road ice in the Seoul Metropolitan Area (SMA), Korea (UMS-Seoul), is introduced. Two case studies demonstrate that the observed data have a great potential to help to understand the boundary-layer structures more deepl and provide useful meteorological information in the SMA.

The Turbulence and Intermittency Long-Duration Atmospheric Experiment (TILDAE) was developed to characterize small-scale fluctuations in the troposphere and stratosphere. The mission's key instrument, a customized sonic anemometer, made high-speed calibrated measurements of the 3-D wind velocity and air temperature. TILDAE was incorporated as an "add-on" experiment to the payload of a NASA long-duration balloon mission that launched in January 2016 from McMurdo Station, Antarctica.

Three methods for estimating the boundary layer height using aerosol backscatter measurements are evaluated here. Radiosonde profiles are used to evaluate aerosol-backscatter-derived boundary layer heights. Overall good agreement between radiosonde and all aerosol-derived boundary layer heights was found, and specific limitations to each method are discussed. A recommended method is given for future aerosol backscatter retrieval of the boundary layer height.

The design of an ion trap aerosol mass spectrometer was improved, allowing for the instrument's first field deployment. Detection limits were found to be sufficiently low for ambient measurements. Via MS-MS measurements the instrument is capable of differentiating ion fragments of different elemental compositions, but also fragments which only differ in their molecular structures. This could allow for e.g. the differentiation between sugars and carboxylic acids by MS–MS studies on m/z 60 and 73.

Aerosol particles produced by gas-to-particle conversion in the atmosphere might influence the climate due to their effects on cloud formation. Characterizing the early growth of newly formed particles is extremely challenging. We present the development and characterization of an instrument that measures the evolution of particles smaller than 10 nm with high time resolution and/or high sensitivity to low concentrations. It can help quantify the characteristics of early nanoparticle growth.