Abstract. The Satellite Application Facility on Climate Monitoring (CM-SAF) aims at the provision of satellite-derived geophysical parameter data sets suitable for climate monitoring. CM-SAF provides climatologies for Essential Climate Variables (ECV), as required by the Global Climate Observing System implementation plan in support of the UNFCCC. Several cloud parameters, surface albedo, radiation fluxes at the top of the atmosphere and at the surface as well as atmospheric temperature and humidity products form a sound basis for climate monitoring of the atmosphere. The products are categorized in monitoring data sets obtained in near real time and data sets based on carefully intercalibrated radiances. The CM-SAF products are derived from several instruments on-board operational satellites in geostationary and polar orbit as the Meteosat and NOAA satellites, respectively. The existing data sets will be continued using data from the instruments on-board the new joint NOAA/EUMETSAT Meteorological Operational Polar satellite. The products have mostly been validated against several ground-based data sets both in situ and remotely sensed. The accomplished accuracy for products derived in near real time is sufficient to monitor variability on diurnal and seasonal scales. The demands on accuracy increase the longer the considered time scale is. Thus, interannual variability or trends can only be assessed if the sensor data are corrected for jumps created by instrument changes on successive satellites and more subtle effects like instrument and orbit drift and also changes to the spectral response function of an instrument. Thus, a central goal of the recently started Continuous Development and Operations Phase of the CM-SAF (2007–2012) is to further improve all CM-SAF data products to a quality level that allows for studies of interannual variability.

We report a molecular dynamics simulation of selenium, described by a three-body interaction. The temperatures T g and T c and the structural properties are in agreement with experiment. The mean nearest neighbor coordination number is 2.1. A small prepeak at about 1 Å Ϫ1 can be explained in terms of void correlations. In the intermediate self-scattering function, i.e., the density fluctuation correlation, classical behavior, ␣ and ␤ regimes, is found. We also observe the plateau in the ␤ regime below T g . In a second step, we investigated the heterogeneous and/or homogeneous behavior of the relaxations. At both short and long times the relaxations are homogeneous ͑or weakly heterogeneous͒. In the intermediate time scale, lowering the temperature increases the heterogeneity. We connect these different domains to the vibrational ͑ballistic͒, ␤ and ␣ regimes. We have also shown that the increase in heterogeneity can be understood in terms of relaxations.

We present Monte Carlo simulations of discotic molecules using the Gay-Berne potential with shape (kappa) and energy (kappa(')) anisotropies. Following the previous work of Bates and Luckhurst [J. Chem. Phys. 104, 6696 (1996)] at kappa=0.345, kappa(')=0.2 when we determine the sequence of different phases at the same reduced pressure P(*)=50, we find an additional phase at low temperatures corresponding to an orthorhombic crystalline phase and we characterize it. Keeping the shape anisotropy fixed at kappa=0.2, we determine the evolution of the phase diagram with varying energy anisotropy. At high kappa('), low anisotropy, the system is not able to build columns while at low kappa('), the system exhibits both orthorhombic crystal as well as hexagonal liquid crystal phases over a wide range of pressures and temperatures. The domain of stability of the nematic phase is found to systematically shift towards higher pressures as kappa(') decreases.

We report an investigation of the heterogeneity in supercooled liquids and glasses using the non-Gaussianity parameter. We simulate selenium and a binary Lennard-Jones system by molecular dynamics. In the non-Gaussianity three time domains can be distinguished: an increase on the ps scale due to the vibrational (ballistic) motion of the atoms, followed by a growth, due to local relaxations ( beta relaxation) at not too high temperatures, and finally a slow drop at long times. The non-Gaussianity follows in the intermediate time domain a sqrt[t] law. This is explained by collective hopping and dynamic heterogeneity. We support this finding by a model calculation.

Random packings containing 8192 hard spheres have been built with an ecient computer algorithm for various packing fractions up to c = 0:643, a value close to the upper limit c b ' 0:649. Long-range correlations and local order have been investigated via the calculation of the two-point correlation function g(r) and the Voronoi tessellation, respectively. The g(r) curve exhibits larger damped oscillations characterized by a correlation length which increases with c and whose extrapolation for c > c b diverges at c 0 = 0:754, which would be the volume fraction of an ideal icosahedral order. Correlatively, when they are extrapolated in the same manner, most of the geometrical characteristics of the Voronoi cells converge to their corresponding values for the perfect dodecahedron circumscribed around a sphere.