Procedures Used for Airborne Measurements of Upwelling Infrared Radiation

We analyze the errors of airborne radiometric measurements of the infrared upwelling radiation I _x of the surface performed using conventional and modified procedures (with calibrators in the form of flat reflecting mirror-like surfaces oriented to reflect the measured radiation I _x to the radiometer in the process of calibration) for the modes of operation of a radiometer with and without thermostatic control. We propose relations for finding I _x as well as for the instrumental and procedural errors and give recommendations for their reduction. It is shown that the modified procedure leads to smaller errors than the conventional procedure.     

Seasonal variations of the Arabian Sea level anomaly fields and circulation

The changes in the field of the Arabian Sea level anomaly and the geostrophic currents are analyzed based on the data of satellite altimetry measurements in 1993–2008 within the framework of the AVISO project. On the intra-annual scale, the current field generally agrees with the circulation schemes published in a number earlier works. Their differences are due to the occurrence of the mesoscale eddies and jet currents revealed by the authors.     

Ophiolites of Western Tyva as fragments of a late Vendian Island arc of the Paleoasian ocean

Doklady Earth Sciences -     

Comparative analysis of pollution of the surface atmospheric layer in such megalopolises as Moscow and Beijing

The results of simultaneous investigations of atmospheric aerosol in two large megalopolises—Moscow and Beijing—are presented. The purpose of these investigations was to compare parameters and reveal common characteristics of urban aerosols. Aerosol parameters were measured in the megalopolises simultaneously from October 23, 2007, through November 2, 2007. The mass concentrations of aerosols were measured continuously with a nephelometer (Mosscow) and discretely with the use of aspiration samplers according to the weight method (Moscow, Beijing). The number concentration and the particle size distribution function were determined with analyzers of the size spectrum in the interval 0.15–15.0 μm and were measured synchronously with sampling for elementary analysis. The elementary compositions of samples were determined by mass spectrometry, which made it possible to identify 60 chemical elements.     

Stellar content of the metal-poor galaxy DDO 68

Based on archival Hubble Space Telescope ACS/WFC images, we have performed stellar photometry for the metal-poor galaxy DDO 68. The apparent distributions of stars of different ages and stellarmetallicity determinations indicate that DDO68 is a systemof two galaxies that have different stellar metallicities (Z = 0.004 and 0.001) and are in the stage of interaction or merging. We have determined the distance to DDO 68, D = 12.0 ± 0.3 Mpc, which differs significantly from previous estimates of the distance to this system. A concentration of red giants is observed outside DDO 68. This can be interpreted as the periphery of a partially visible low-surface-brightness galaxy located at the same distance as DDO 68. Comparison of the constructed CM diagrams with theoretical isochrones from Bertelli et al. has allowed us to determine that the age of each galaxy is at least 10 Gyr.     

MHD Models and Laboratory Experiments of Jets

Jet research has long relied upon a combination of analytical, observational and numerical studies to elucidate the complex phenomena involved. One element missing from these studies (which other physical sciences utilize) is the controlled experimental investigation of such systems. With the advent of high-power lasers and fast Z-pinch machines it is now possible to experimentally studysimilar systems in a laboratory setting. Such investigations can contribute in two useful ways. They can be used for comparison with numerical simulations as a means to validate simulation codes. More importantly, however, such investigations can also be used to complement other jet research, leading to fundamentally new knowledge. In the first part of this article, we analyze the evolution of magnetized wide-angle winds in a collapsing environment. We track the ambient and wind mass separately and describe a physical mechanism by which an ionized central wind can entrain the ambient gas giving rise to internal shells of molecular material on short time scales. The formation of internal shells in molecular outflows has been found to be an important ingredient in describing the observations of convex spurs in P-V diagrams (Hubble wedges in M-V diagrams).In the second part, we present astrophysically relevant experiments in which supersonic jets are created using a conical wire array Z-pinch. The conically convergent flow generates a standing shock around the axis which collimates the flow into a Mach ～ 30 jet. The jet formation process is closely related to the work of Cantó et al. (1988) for hydrodynamic jet collimation. The influence of radiative cooling on collimation and stability is studied by varying the wire material (Al, Fe, and W).