A5061778534- Atmospheric Ozone and Climate
- Atmospheric chemistry and aerosols
- Spectroscopy and Laser Applications
- Atmospheric aerosols and clouds
- Atmospheric and Environmental Gas Dynamics
- Molecular Spectroscopy and Structure
- Meteorological Phenomena and Simulations
- Calibration and Measurement Techniques
- Spaceflight effects on biology
- Scientific Measurement and Uncertainty Evaluation
- Environmental Monitoring and Data Management
- Electrostatics and Colloid Interactions
- Spacecraft and Cryogenic Technologies
- Phase Equilibria and Thermodynamics
- Advanced optical system design
- Magnetic and Electromagnetic Effects
- Microfluidic and Bio-sensing Technologies
- Acoustic Wave Resonator Technologies
- Ionosphere and magnetosphere dynamics
- Adaptive optics and wavefront sensing
- Laser-induced spectroscopy and plasma
- Air Quality and Health Impacts
- Flow Measurement and Analysis
- Spacecraft Design and Technology
- Methane Hydrates and Related Phenomena
Rutherford Appleton Laboratory
2008-2021
Science and Technology Facilities Council
2014
Fraunhofer Centre for Applied Photonics
2002
University of Strathclyde
1995-2000
The report of an IUPAC Task Group, formed in 2011 on "Intensities and line shapes high-resolution spectra water isotopologues from experiment theory" (Project No. 2011-022-2-100), profiles isolated rotational-vibrational transitions perturbed by neutral gas-phase molecules is presented. well-documented inadequacies the Voigt profile (VP), used almost universally databases radiative-transfer codes, to represent pressure effects Doppler broadening vibrational-rotational pure rotational...
[1] In most near-infrared atmospheric windows, absorption of solar radiation is dominated by the water vapor self-continuum, and yet there a paucity measurements in these windows. We report new laboratory self-continuum at temperatures between 293 472 K pressures from 0.015 to 5 atm four windows 1 4 μm (10000–2500 cm−1); are made over wider range wavenumbers, temperatures, than any previous measurements. They show that typically one order magnitude stronger given representations continuum...
Laboratory Fourier transform spectroscopy of pure water vapor and mixed with air has been conducted between 1200 8000 cm −1 at temperatures 293 351 K the purpose detecting characterizing continuum. The spectral features continuum within major absorption bands are presented compared where possible to those from previous experimental studies commonly used MT_CKD CKD models. It was observed that in main, both models adequately capture general form continuum; however, there were a number...
For a long time, it has been believed that atmospheric absorption of radiation within wavelength regions relatively high infrared transmittance (so-called 'windows') was dominated by the water vapour self-continuum, is, spectrally smooth caused H(2)O--H(2)O pair interaction. Absorption due to foreign continuum (i.e. mostly H(2)O--N(2) bimolecular in Earth's atmosphere) considered be negligible windows. We report new retrievals from high-resolution laboratory measurements at temperatures...
Spectroscopic catalogues, such as GEISA and HITRAN, do not yet include information on the water vapour continuum that pervades visible, infrared microwave spectral regions. This is partly because, in some regions, there are rather few laboratory measurements conditions close to those Earth's atmosphere; hence understanding of characteristics absorption still emerging. particularly so near-infrared where has been renewed interest activity recent years. In this paper we present a critical...
Abstract The complex refractive indices of eight volcanic ash samples, chosen to have a representative range SiO 2 contents, were retrieved from simultaneous measurements their spectral mass extinction coefficient and size distribution. coefficients, at 0.33–19 μm, measured using two optical systems: Fourier transform spectrometer in the infrared diffraction grating spectrometers covering visible ultraviolet wavelengths. particle distribution was scanning mobility sizer an counter; values...
Abstract. The extinction spectra of laboratory generated sea salt aerosols have been measured from 1 μm to 20 using a Bruker 66v/S FTIR spectrometer. Concomitant measurements include temperature, pressure, relative humidity and the aerosol size distribution. refractive indices determined simple harmonic oscillator band model (Thomas et al., 2004) for with humidities at eight different values between 0.4% 86%. resulting index show significant discrepancies when compared existing calculated...
• An apparatus for measuring the mass extinction coefficient (MEC) and size distribution of suspended solid aerosol particles is detailed. The wavelength range measurements was 0.33–19mu m . Measurements quartz amorphous silicon dioxide are presented. Experimental uncertainties in MEC values given. measured compared to three scattering models: Mie theory, T-matrix theory applying spheroids, Rayleigh CDE model. Simultaneous were made spectral (from 0.33–19 µm) particle silica dispersed...
CFC-113a (CF3CCl3), CFC-112 (CFCl2CFCl2) and HCFC-133a (CF3CH2Cl) are three newly detected molecules in the atmosphere that almost certainly emitted as a result of human activity. It is important to characterise possible contribution these gases radiative forcing climate change also provide information on CO2-equivalence their emissions. We report new laboratory measurements absorption cross-sections compounds at resolution 0.01 cm−1 for two temperatures 250 K 295 spectral range 600–1730...
Intensities and self-broadening coefficients are presented for about 460 of the strongest water vapour lines in spectral regions 1400–1840 cm−1 3440–3970 at room temperature, obtained from rather unique measurements using a 5-mm-path-length cell. The retrieved line parameters compared with those HITRAN database ver. 2008 2012 recent ab-initio calculations. Both intensities half-widths on average reasonable agreement HITRAN-2012. Maximum systematic differences do not exceed 4% (1600 band) 7%...
Remote sensing of the atmosphere from space plays an increasingly important role in weather forecasting. Exploiting observations latest generation satellites relies on accurate knowledge fundamental spectroscopy, including water vapour continuum absorption. Field campaigns involving Facility for Airborne Atmospheric Measurements research aircraft have collected a comprehensive dataset, comprising remotely sensed infrared radiance collocated with measurements temperature and humidity...
Abstract This work presents measurements of the spectral extinction black carbon aerosol from 400 nm to 15 μm. The was generated using a Miniature Combustion Aerosol Standard soot generator and then allowed circulate in an cell where its measured grating spectrometer visible Fourier transform infrared. Size distribution, number concentration, mass cross sections have also been obtained single‐particle samplers. A mean section at 550 8.3 ± 1.6 m 2 g −1 is found which, assuming reasonable...
Microsized particles play an important role in many diverse areas of science and technology, for example, surface reactions micron-sized a key astrochemistry, plasma reactors atmospheric chemistry. To date much our knowledge such chemistry is derived from 'traditional' science-based research. However, the large area morphology material commonly used techniques may not necessarily mimic that on micron/nano scale particles. Hence, new generation experiments which spectroscopy (e.g., albedo)...
Two un-ionised molecular hydrate complexes, previously observed by Fourier-transform spectroscopy in flat films of vapour deposited sulfuric acid, have been identified directly aerosols nucleated from SO3 and H2O a 75 dm3 coolable spectroscopic cell. Aerosols 1 : complex H2SO4·H2O generated at 195 K also formed cooled liquid acid aerosols. A second polymeric metastable the type (H2SO4.2H2O)n has as initial material during nucleation process aerosol K. These species are likely to play an...
Motivated by the detection of infrared absorption bands from atmospheric cluster ions in laboratory experiments, a narrowband filter radiometer has been constructed for ion atmosphere. It uses centered at 9.15 μm wavelength with 5% bandwidth, protected diamond-like-carbon coated germanium auxiliary filter, and fitted to standard pyrradiometer. A sensitivity (29.3±0.1) μV/(W m−2) determined calibration using blackbody source. Atmospheric experiments show that radiometer, when used stable,...
We have constructed a coolable spectroscopic cell for characterizing the physical and chemical properties of simulated atmospheric aerosol particles. The is designed experiments in which refractive indices, freezing temperatures, phase composition wide range types are measured. relatively large volume (0.075 m(3)) reduces wall-aerosol interactions allows residence time to exceed 2 h. has been optically interfaced Fourier-transform spectrometers record broadband infrared, visible, ultraviolet...
Extinction spectra of H 2 SO 4 ‐HNO 3 ‐H O supercooled ternary solution (STS) aerosol particles, fully covering the mid‐ and near‐infrared region from 750 to 13,000 cm −1 (13.9 0.7 μm), have been measured in laboratory using a 75 dm volume coolable cell coupled with Fourier transform spectrometer. The STS were recorded at temperatures close those encountered polar stratosphere fitted spectrum modelled by combining Mie scattering theory published thin film refractive index data. Good...
transitions Jonathan Tennyson1, Peter F. Bernath2, Alain Campargue3, Attila G. Csaszar4, Ludovic Daumont,5 Robert R. Gamache6, Joseph T. Hodges7, Daniel Lisak8, Olga V. Naumenko9, Laurence S. Rothman10, Ha Tran11, Jean-Michel Hartmann11, Nikolai Zobov12, Jeanna Buldyreva13, Chris D. Boone14, Maria De Vizia15, Livio Gianfrani15, McPheat16, Damien Weidmann16, Murray17, Ngoc Hoa Ngo18, Oleg L. Polyansky1,12 1Department of Physics and Astronomy, University College London, UK; 2Department...
Abstract. The extinction spectra of laboratory generated sea salt aerosols have been measured from 1 μm to 20 using a Bruker 66v/S FTIR spectrometer. Concomitant measurements include temperature, pressure, relative humidity and the aerosol size distribution. refractive indices determined simple harmonic oscillator band model (Thomas et al., 2004) for with humidities between 0.1% 100% salt. resulting index show significant discrepancies when compared existing indices.