Long-term evolution and seasonal modulation of methanol above Jungfraujoch (46.5° N, 8.0° E): optimisation of the retrieval strategy, comparison with model simulations and independent observations
W. Bader, T. Stavrakou, J.-F. Muller, S. Reimann, C. D. Boone, J. J. Harrison, O. Flock, B. Bovy, B. Franco, B. Lejeune, C. Servais, and E. Mahieu Atmos. Meas. Tech., 7, 3861-3872, 2014 AbstractFinal Revised Paper (PDF, 2021 KB)Discussion Paper (AMTD)
21 Nov 2014
Effect of ions on the measurement of sulfuric acid in the CLOUD experiment at CERN
Quantifying the value of redundant measurements at GCOS Reference Upper-Air Network sites
Summary: The paper provides the community with criteria to quantify the value of complementary climate measurements and to assess how the uncertainty in a measurement of an ECV is reduced by measurement complementarity. The study demonstrates the potential of entropy and mutual correlation, defined in information theory as metrics for quantifying synergies, and shows that the random uncertainties of a single instrument time series of TCWV can be strongly reduced by including complementary measurements.
A compact PTR-ToF-MS instrument for airborne measurements of volatile organic compounds at high spatiotemporal resolution
Summary: This paper describes a new airborne instrument for measuring the trace gas composition of the atmosphere.
M. Müller, T. Mikoviny, S. Feil, S. Haidacher, G. Hanel, E. Hartungen, A. Jordan, L. Märk, P. Mutschlechner, R. Schottkowsky, P. Sulzer, J. H. Crawford, and A. Wisthaler Atmos. Meas. Tech., 7, 3763-3772, 2014 AbstractFinal Revised Paper (PDF, 3194 KB)Supplement (226 KB)Discussion Paper (AMTD)
17 Nov 2014
Application of GPS radio occultation to the assessment of temperature profile retrievals from microwave and infrared sounders
Satellite observations of peroxyacetyl nitrate from the Aura Tropospheric Emission Spectrometer
Summary: Peroxyacetyl nitrate (PAN) plays an important role in the distribution of lower-atmospheric ozone. PAN can be transported far from the original pollution source, leading to ozone formation and degraded air quality in remote areas. Satellite observations from the Tropospheric Emission Spectrometer (TES) are sensitive to PAN at lower altitude than previous global data sets. We describe characteristics of the data and show elevated PAN associated with boreal fires and outflow of Asian pollution.
Mixing-layer height retrieval with ceilometer and Doppler lidar: from case studies to long-term assessment
Summary: Two different methods for the determination of the mixing layer height (MLH) are investigated with a one-year data set from central Europe: (i) based on a significant gradient of backscatter and (ii) on the vertical velocity. The aerosol-based method shows significant over-estimation in the morning hours when the ML grows into the residual layer and late afternoon hours when turbulent mixing decays. This results in systematic over-estimation of average characteristcs as e.g. maximum MLH.
Direct aerosol chemical composition measurements to evaluate the physicochemical differences between controlled sea spray aerosol generation schemes
Summary: Sea spray aerosol particles represent a system of relatively high chemical complexity. The chemical composition of sea spray aerosol particles was shown in this study to be directly determined by the method used to produce bubbles, which produce aerosol upon bursting at the sea surface. Using methods which deviate from natural breaking waves directly translated into differences in the measured particle sizes and the chemical mixing state of laboratory-generated sea spray aerosol particles.
D. B. Collins, D. F. Zhao, M. J. Ruppel, O. Laskina, J. R. Grandquist, R. L. Modini, M. D. Stokes, L. M. Russell, T. H. Bertram, V. H. Grassian, G. B. Deane, and K. A. Prather Atmos. Meas. Tech., 7, 3667-3683, 2014 AbstractFinal Revised Paper (PDF, 1377 KB)Discussion Paper (AMTD)
06 Nov 2014
Rapid, optical measurement of the atmospheric pressure on a fast research aircraft using open-path TDLAS
MIPAS temperature from the stratosphere to the lower thermosphere: Comparison of vM21 with ACE-FTS, MLS, OSIRIS, SABER, SOFIE and lidar measurements
Summary: We present the new vM21 MIPAS temperatures from 20 to 102km for all of its 2005-2012 MA, UA and NLC measurements. The main upgrades are the update of ESA L1b spectra, spectroscopic database and O and CO2 climatologies, and improvement in Tk-gradient and offset regularizations and apodization accuracy. The vM21 Tk's correct the main systematic errors of previous versions and lead to remarkable improvement in their comparisons with ACE-FTS, MLS, OSIRIS, SABER and SOFIE and the MLO and TMF lidars.
M. García-Comas, B. Funke, A. Gardini, M. López-Puertas, A. Jurado-Navarro, T. von Clarmann, G. Stiller, M. Kiefer, C. D. Boone, T. Leblanc, B. T. Marshall, M. J. Schwartz, and P. E. Sheese Atmos. Meas. Tech., 7, 3633-3651, 2014 AbstractFinal Revised Paper (PDF, 5494 KB)Supplement (266 KB)Discussion Paper (AMTD)
06 Nov 2014
The MOPITT Version 6 product: algorithm enhancements and validation
Summary: The MOPITT Version 6 product for carbon monoxide (CO) incorporates several enhancements. First, a geolocation bias has been eliminated. Second, the new variable a priori for CO concentrations is based on simulations performed with the CAM-Chem chemical transport model for the years 2000-2009. Third, required meteorological fields are extracted from the MERRA reanalysis. Finally, a retrieval bias in the upper troposphere was substantially reduced. Validation results are presented.
M. N. Deeter, S. Martínez-Alonso, D. P. Edwards, L. K. Emmons, J. C. Gille, H. M. Worden, C. Sweeney, J. V. Pittman, B. C. Daube, and S. C. Wofsy Atmos. Meas. Tech., 7, 3623-3632, 2014 AbstractFinal Revised Paper (PDF, 1399 KB)Discussion Paper (AMTD)
05 Nov 2014
Amine permeation sources characterized with acid neutralization and sensitivities of an amine mass spectrometer
Summary: Amine permeation tubes were quantified via absorption of gaseous amines by dilute acid solutions. Calibrations of an amine mass spectrometer with these permeation tubes show that the mass spectrometer is very sensitive to amines. Measurements of ambient amines are presented from two recent field campaigns. The amine mass spectrometer instrumentation and sampling arrangements are extensively discussed.