Dietrich Müller

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[1] Cirrus formation and geometrical and optical properties of tropical cirrus as a function of height and temperature are studied on the basis of INDOEX (Indian Ocean Experiment) lidar and radiosonde measurements and satellite observations of deep convection causing the generation of anvil cirrus. Lidar and radiosonde measurements were conducted at Hulule(More)
[1] More than 130 observation days of the horizontal and vertical extent of Saharan dust intrusions over Europe during the period May 2000 to December 2002 were studied by means of a coordinated lidar network in the frame of the European Aerosol Research Lidar Network (EARLINET). The number of dust events was greatest in late spring, summer, and early(More)
The detection of spectral variability of the γ-ray blazar Mrk 421 at TeV energies is reported. Observations with the Whipple Observatory 10 m γ-ray telescope taken in 2000/2001 revealed exceptionally strong and long-lasting flaring activity. Flaring levels of 0.4 to 13 times that of the Crab Nebula flux provided sufficient statistics for a detailed study of(More)
We describe a new measurement of the intensities of the heavy primary cosmic-ray nuclei O, Ne, Mg, Si, and Fe from 10 GeV amu À1 to energies beyond 1 TeV amu À1. The measurement was conducted in 1999 during a 1 day test flight of the Transition Radiation Array for Cosmic Energetic Radiation (TRACER), a new cosmic-ray telescope designed for long-duration(More)
[1] Traditionally there has been a lack of intensive measurements directly over dust sources for validating the accuracy of dust models. Utilizing the valuable and unprecedented SAMUM 2006 field campaign dust dataset in North Africa, we assess the performance and discuss the limitations of a state-of-the-art dust regional model to reproduce the complex dust(More)
We present measurements acquired by the world's first airborne 3 backscatter (β) + 2 extinction (α) High Spectral Resolution Lidar (HSRL-2). HSRL-2 measures particle backscatter coefficients at 355, 532, and 1064 nm, and particle extinction coefficients at 355 and 532 nm. The instrument has been developed by the NASA Langley Research Center. The instrument(More)
We present novel evidence for fine structure observed in the net circular polarization (NCP) of a sunspot penumbra based on spectropolarimetric measurements utilizing the Zeeman-sensitive Fe i 630.2 nm line. For the first time we detect filamentary organized fine structure of the NCP on spatial scales that are similar to the inhomogeneities found in the(More)
Observations of cosmic-ray electrons and positrons have been made with a new balloon-borne detector, HEAT (the " High-Energy Antimat-ter Telescope "), first flown in 1994 May from Fort Sumner, NM. We describe the instrumental approach and the data analysis procedures, and we present results from this flight. The measurement has provided a new determination(More)
Precise observations of the energy spectra and relative abundances of cosmic-ray nuclei require instruments that exhibit individual charge resolution and a calibrated energy response. If energies up to ∼ 10 15 eV are to be covered, the low intensity of the heavier nuclei (Z ² 3) also mandates detector areas of several square meters. X-ray transition(More)