[1] The first continuous and high temporal resolution record of spectral albedo and transmittance of snow and sea ice in the Arctic Ocean over an entire summer season is presented. Measurements were performed at a manned station on multiyear sea ice in the Transpolar Drift during the drift of the schooner Tara from April to September 2007. Concurrent autonomous measurements of ice mass balance and weekly observations of snow and sea-ice properties complement the data set. The seasonality of physical and biological processes of snow and sea ice is characterized, including quantification of melt onset (10 June), melt season duration, and freeze onset (15 August). Over one year, approximately two thirds of the transmitted energy reached the ocean during the 66-day-long melt season. During the second half of July, transmitted irradiance decreased by 90% and absorption in and directly under the ice increased, significantly affecting the vertical partitioning of irradiance. The spectral radiation time series suggests that high biomass abundance in or below the sea ice caused this decrease. Comparing the spectral data set with broadband albedo data measured at the same location shows that 90% of the temporal variability of broadband albedo can be explained by variability in spectral albedo integrated over the limited wavelength range. The combination of spectral radiation and ice mass balance measurements allows a comprehensive description, and quantification, of snow and sea-ice processes, even with minimal additional in situ observations, suggesting such data sets can be collected autonomously to provide insight into the physical and biological processes on sea ice.

Active layer temperatures are presented from a rock glacier in the Swiss Alps. The data represent a full year (2002) covering parts of two very different winters. Winter/spring 2002 was very cold and dry; fall 2002 was characterized by an unusual amount of snow. Active layer temperatures are examined together with climate data and are used to discuss the processes which control the thermal regime of an active layer on a slope of a bouldery rock glacier surface. The development of the snow cover as well as the snow depth are shown to be essential, but the non-linear heating of the bouldery material with increasing air temperatures and the micro-topography of the rock glacier surface are also shown to have an influence on the thermal regime of the active layer. Furthermore, it is shown that the advective air movement within the blocky deposit has much less influence on the thermal regime than the vertical displacement of air masses. This is contradicts earlier literature on the subject. Plate 1 Climate data and active layer temperature from 2002. (I) Snow depth and albedo; (II) wind speed, air and surface temperature; (III) short wave incoming, net and long wave outgoing radiation; (IV) temperatures of the seven thermistors S1-S7. The year is divided into five main periods: (A) active layer cooling before the onset of a lasting snow cover, (B) shallow snow cover which allows a connection between the temperature of the atmosphere and the active layer and negative active layer temperatures, (C) lasting snow cover with no connection between atmosphere and active layer, (D) zero curtain, and (E) above zero active layer temperatures. The two black arrows show periods of missing data; the white arrow indicates the onset of melt.Plate 2 The temperatures measured in the active layer during the first 12 days of January 2002. The two thermistors which measure the air temperature in the cavities react strongly while the thermistors drilled into the rock react in a much more attenuated way, but they still do react.

The paper briefly presents some essential concepts and features of light fields with strong spatial inhomogeneity of amplitude, phase, polarization, and other parameters. It contains a characterization of optical vortices, speckle fields, polarization singularities. A special attention is paid to the field dynamical characteristics (energy, momentum, angular momentum, and their derivatives), which are considered not only as mechanical attributes of the field but also as its meaningful and application-oriented descriptive parameters. Peculiar features of the light dynamical characteristics in inhomogeneous and dispersive media are discussed. The dynamical properties of paraxial beams and evanescent waves (including surface plasmon-polaritons) are analyzed in more detail; in particular, a general treatment of the extraordinary spin and momentum, orthogonal to the main propagation direction, is outlined. Applications of structured light fields for optical manipulation, metrology, probing, and data processing are described.

A new technique for displacement measurement is proposed that makes use of phase singularities in the complex signal generated by a Laguerre-Gauss filter operation applied to a speckle pattern. The core structures of phase singularities are used as unique fingerprints attached to the object surface, and the displacement is determined by tracing the movement of registered phase singularities with their correspondence being identified by the fingerprints. Experimental results for translational and rotational displacement measurements are presented that demonstrate large dynamic range and high spatial resolution of the proposed optical vortex metrology.

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