1,721,170 research outputs found
Data sets for the research article "High-resolution optical constants of crystalline ammonium nitrate for infrared remote sensing of the Asian Tropopause Aerosol Layer" by Wagner et al. (2021) in Atmospheric Measurement Techniques
No full textThe data comprise eleven tables containing low-temperature infrared refractive indices for crystalline ammonium nitrate. The syntax of the file names and the contents of the tables are explained in the additional text file "info.txt". The tables with the refractive index data can be opened in standard text editors or imported in spreadsheet programs like Microsoft Excel. The data are separated by tabs as a delimiter
Light spectra measured inside the AIDA aerosol and cloud simulation chamber
No full textSpektren der Lichtquelle in der AIDA Aerosol und Wolkenkamme
Comparison of scanning aerosol LIDAR and in situ measurements of aerosol physical properties and boundary layer heights
No full textThe spatiotemporal distribution of aerosol particles in the atmosphere has a great impact on radiative transfer, clouds, and air quality. Modern remote sensing methods, as well as airborne in situ measure- ments by unpiloted aerial vehicles (UAV) or balloons, are suitable tools to improve our understanding of the role of aerosol particles in the atmosphere. To validate the measurement capabilities of three relatively new measurement systems and to bridge the gaps that are often encountered between remote sensing and in situ ob- servation, as well as to investigate aerosol particles in and above the boundary layer, we conducted two measure- ment campaigns and collected a comprehensive dataset employing a scanning aerosol lidar, a balloon-borne ra- diosonde with the Compact Optical Backscatter Aerosol Detector (COBALD), an optical particle counter (OPC) on a UAV, and a comprehensive set of ground-based instruments. The extinction coefficients calculated from near-ground-level aerosol size distributions measured in situ are well correlated with those retrieved from lidar measurements, with a slope of 1.037 ± 0.015 and a Pearson correlation coefficient of 0.878, respectively. Verti- cal profiles measured by an OPC-N3 on a UAV show similar vertical particle distributions and boundary layer heights to lidar measurements. However, the sensor, OPC-N3, shows a larger variability in the aerosol backscat- ter coefficient measurements, with a Pearson correlation coefficient of only 0.241. In contrast, the COBALD data from a balloon flight are well correlated with lidar-derived backscatter data from the near-ground level up to the stratosphere, with a slope of 1.063 ± 0.016 and a Pearson correlation coefficient of 0.925, respectively. This consistency between lidar and COBALD data reflects the good data quality of both methods and proves that lidar can provide reliable and spatial distributions of aerosol particles with high spatial and temporal resolutions. This study shows that the scanning lidar has the capability to retrieve backscatter coefficients near the ground level (from 25 to 50 m above ground level) when it conducts horizontal measurement, which is not possible for verti- cally pointing lidar. These near-ground-level retrievals compare well with ground-level in situ measurements. In addition, in situ measurements on the balloon and UAV validated the scanning lidar retrievals within and above the boundary layer. The scanning aerosol lidar allows us to measure aerosol particle distributions and profiles from the ground level to the stratosphere with an accuracy equal to or better than in situ measurements and with a similar spatial resolution
Kinetics, SOA yields and chemical composition of secondary organic aerosol from β-caryophyllene ozonolysis with and without nitrogen oxides between 213 and 313 K
No full textThe data in the Excel file is related to the publication Gao et al., ACP, 2022. Each sheet of the Excel file corresponds to one plot in the publication. The data originates mainly from FIGAERO-CIMS and HR-ToF-AMS (both Aerodyne Inc.) measurements. “Kinetics, SOA yields and chemical composition of secondary organic aerosol from β-caryophyllene ozonolysis with and without nitrogen oxides between 213 and 313 K” Linyu Gao1,2; Junwei Song1,2; Claudia Mohr3; Wei Huang4; Magdalena Vallon1; Feng Jiang1,2; Thomas Leisner1,5; and Harald Saathoff1 1 Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany 2 Institute of Geography and Geoecology, Working Group for Environmental Mineralogy and Environmental System Analysis, Karlsruhe Institute of Technology, Karlsruhe, Germany 3 Department of Environmental Science, Stockholm University, Stockholm, Sweden 4 Institute for Atmospheric and Earth System Research / Physics, Faculty of Science, University of Helsinki, Helsinki, Finland 5 Institute of Environmental Physics, Heidelberg University, Heidelberg, Germany Correspondence to: Linyu Gao ([email protected]) and Dr. Harald Saathoff ([email protected]) Atmos. Chem. Phys. Discuss. [preprint], https://doi.org/10.5194/acp-2021-1067, in review, 2022. (accepted on April 4th, 2022
Chromophores and chemical composition of brown carbon characterized at an urban kerbside by excitation-emission spectroscopy and mass spectrometry
No full textThe data in the Excel files are related to the publication Jiang et al., ACP, 2022. Each sheet of the Excel files corresponds to one plot in the publication as repeated below. The data originates mainly from Aqualog and FIGAERO-CIMS measurements. The figures and captions from the publication are shown in the following to allow for a good understanding of the data files. Jiang, F., Song, J., Bauer, J., Gao, L., Vallon, M., Gebhardt, R., Leisner, T., Norra, S., and Saathoff, H.: Chromophores and chemical composition of brown carbon characterized at an urban kerbside by excitation-emission spectroscopy and mass spectrometry, Atmos. Chem. Phys. Discuss. [preprint], https://doi.org/10.5194/acp-2022-465, in review, 2022
Sources of organic gases and aerosol particles and their roles in nighttime particle growth at a rural forested site in southwest Germany
No full textThe composition, sources and chemical transformation of volatile organic compounds (VOCs)
and organic aerosol (OA) particles were investigated during July–August 2021 at a rural forested site in southwest
Germany, 10 km north of the city of Karlsruhe. VOCs and semi-volatile OA particles were measured with
a proton-transfer-reaction mass spectrometer coupled to the CHemical Analysis of aeRosols ONline particle
inlet (CHARON–PTR-MS). The CHARON-measured OA mass accounted for 62+-18% on average of the total
OA mass (4.2+-2.8 μgm-3) measured concurrently with an aerosol mass spectrometer (AMS). The total concentrations
of measured VOCs ranged from 7.6 to 88.9 ppb with an average of 31.2+-13.4 ppb. Positive matrix
factorization (PMF) was used to identify major source factors of VOCs and OA particles. Three types of oxygenated
VOC (OVOC), namely aromatic OVOCs, biogenic OVOCs and aged OVOCs, contributed on average
11%+-9 %, 37%+-29% and 29%+-21% of total VOC concentrations, respectively. The results of AMS–PMF
indicated substantial contributions of oxygenated organic compounds to OA particle mass. Three secondary OA
(SOA) factors determined by CHARON–PMF analysis, namely aromatic SOA (5%7 %), daytime biogenic
SOA (17%+-17 %) and nighttime biogenic SOA (28%+-21 %), consistently showed high contributions to the
total CHARON-measured OA mass. Nighttime particle growth was observed regularly in this area, which was
mainly attributed to the semi-volatile organic compounds and organic nitrates formed from the oxidation of
monoterpenes and sesquiterpenes. This study presents the major sources, real-time transformations of VOCs and
OA particles, and nighttime particle formation characteristics for central European forested areas
Data sets for the research article "Solid ammonium nitrate aerosols as efficient ice nucleating particles at cirrus temperatures" by Wagner et al. (2020) in the Journal of Geophysical Research (Atmospheres)
No full textThe data comprise four tables containing low-temperature infrared extinction spectra, temperature- and composition-dependent ice nucleation onsets, and ice nucleation active surface site densities of crystalline AN/AS particles. The tables are provided in ".txt" format and can be opened in standard text editors or imported in spreadsheet programs like Microsoft Excel. Each table contains a comprehensive header describing the contents of the individual columns. The data are separated by tabs as a delimiter
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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