Search results for "Atmospheric observations"
showing 4 items of 4 documents
Microphysical Properties of Ice Crystal Precipitation and Surface-Generated Ice Crystals in a High Alpine Environment in Switzerland
2017
AbstractDuring the Cloud and Aerosol Characterization Experiment (CLACE) 2013 field campaign at the High Altitude Research Station Jungfraujoch, Switzerland, optically thin pure ice clouds and ice crystal precipitation were measured using holographic and other in situ particle instruments. For cloud particles, particle images, positions in space, concentrations, and size distributions were obtained, allowing one to extract size distributions classified by ice crystal habit. Small ice crystals occurring under conditions with a vertically thin cloud layer above and a stratocumulus layer approximately 1 km below exhibit similar properties in size and crystal habits as Antarctic/Arctic diamond …
Modeling Atmospheric Turbulence via Rapid Distortion Theory: Spectral Tensor of Velocity and Buoyancy
2017
Abstract A spectral tensor model is presented for turbulent fluctuations of wind velocity components and temperature, assuming uniform vertical gradients in mean temperature and mean wind speed. The model is built upon rapid distortion theory (RDT) following studies by Mann and by Hanazaki and Hunt, using the eddy lifetime parameterization of Mann to make the model stationary. The buoyant spectral tensor model is driven via five parameters: the viscous dissipation rate ε, length scale of energy-containing eddies L, a turbulence anisotropy parameter , gradient Richardson number (Ri) representing the local atmospheric stability, and the rate of destruction of temperature variance . Model outp…
Observations of molecular hydrogen mixing ratio and stable isotopic composition at the Cabauw tall tower in the Netherlands
2016
AbstractMeasurements of the stable isotopic composition (δD(H2) or δD) of atmospheric molecular hydrogen (H2) are a useful addition to mixing ratio (χ(H2)) measurements for understanding the atmospheric H2 cycle. δD datasets published so far consist mostly of observations at background locations. We complement these with observations from the Cabauw tall tower at the CESAR site, situated in a densely populated region of the Netherlands. Our measurements show a large anthropogenic influence on the local H2 cycle, with frequently occurring pollution events that are characterized by χ(H2) values that reach up to ≈1 ppm and low δD values. An isotopic source signature analysis yields an apparent…
Observations of molecular hydrogen (H2) mixing ratio and stable isotopic composition (deuterium content) at the Cabauw tall tower in the Netherlands
2016
This zip file contains the final corrected data that were used for the journal article "Observations of molecular hydrogen mixing ratio and stable isotopic composition at the Cabauw tall tower in the Netherlands" by Batenburg et al., Atmospheric Environment, 2016, doi:10.1016/j.atmosenv.2016.09.058 Please cite the original AtmosEnv article when using these data. The paper also contains more information about how these data were collected and calibrated, and on how the quality control flags were assigned. All samples were collected at the Cabauw tower, at the CESAR site (51.971° N, 4.927° E, http://www.cesar-observatory.nl/). H2 and deltaD(H2) are calibrated using one to four laboratory re…