Coherent Schwinger Interaction from Darboux Transformation

The exactly solvable scalar-tensor potential of the four-component Dirac equation has been obtained by the Darboux transformation method. The constructed potential has been interpreted in terms of nucleon-nucleon and Schwinger interactions of neutral particles with lattice sites during their channeling Hamiltonians of a Schwinger type is obtained by means of the Darboux transformation chain. The analitic structure of the Lyapunov function of periodic continuation for each of the Hamiltonians of the family is considered.Comment: 12 pages, Latex, six figures; six sections, one figure adde

1. Spatial and temporal evolution of the optical thickness of the Pinatubo aerosol cloud in the northern hemisphere from a network of ship-borne and stationary lidars

International audienceThe vertical profiles of the extinction coefficient and the total optical thickness of the Pinatubo aerosol layer obtained from a network of 5 Rayleigh-Mie lidars are presented here. Three ship-borne lidars (PROFESSOR ZUBOV†, PROFESSOR VIZE†, HENRI POINCARE*) and two fixed lidar stations (OHP* and CEL*) are operated respectively by the Roscomhydromet†, of Russia and of the Service d'Aeronomie du CNRS* of France. The measurements presented are in the altitude range 15-35 km. They were obtained between July 1991 - April 1992 and cover 8°S-60°N latitude and 80°W-6°E longitude. This represents extensive coverage of the western sector of the northern hemisphere, which is partly coincident with UARS satellite coverage. Optical depths of up to 0.2 were observed and maximum extinction coefficient values of 0.08 km-1 were obtained at 24 km and 18°N latitude

2. Morphology and dynamics of the Pinatubo aerosol layer in the northern hemisphere as detected from a ship-borne lidar

International audienceScattering ratios of the Pinatubo aerosol layer obtained by the ship-borne lidar of the Roscomhydromet of Russia on-board PROFESSOR ZUBOV are presented. During a campaign primarily in the low-latitude (8°N-43°N) Atlantic Ocean, 48 days of data were obtained within the 73 day period spanning 11-July and 21-September of 1991 [Avdyushin et al., 1992]. These data show the aerosol cloud to be primarily in the 16-27 km altitude region, with a high degree of variability in the vertical structure and in the longitudinal structure, and to a lesser degree, in the latitudinal structure. Scattering ratios of up to 50 were recorded in the multi-layered structure which was often observed. These are the first lidar observations showing a high degree of zonal variability of the vertical structure of the aerosol layer. We show the latitudinal range of the Pinatubo aerosol cloud in the northern hemisphere over a 2 month period and estimate the latitudinal dispersion rate for the months of the measurements to be approximately 5° latitude per month. A clear periodic variability was observed in the altitude structure during the entire data-set primarily within 8°N-22°N latitude and within the altitude region of the layer, from which a mean zonal wind profile was produced by a spectral analysis of the aerosol profiles