Surface mass balance on Glacier No. 31 in the Suntar–Khayata Range, eastern Siberia, from 1951 to 2014

This study presents a 64-year （1951-2014） reconstruction of the surface mass balance of Glacier No. 31, located in the Suntar-Khayata Range of the eastern Siberia, where the ablation zone is characterized by the extensive dark ice surface. We use a temperature index-based glacier mass-balance model, which computes all major components of glacier mass budget and is forced by daily air temperature and precipitation from a nearby meteorological station. The glacier shows a mean annual mass balance of -0.35 m w.e.a-1 during the past 64 years, with an acceleration of -0.50 m w.e. a^-1 during the recent years. A cumulative mass loss of the glacier is -22.3 m w.e. over the study period, about 56% of which is observed during 1991-2014. In addition to the contribution of temperature rise and precipitation decrease to recent mass loss of the glacier, an experimental analysis, in which the clean and dark ice surfaces are respectively assumed to cover the entire ablation zone, indicates that dark ice surface, caused by insoluble impurities consisting of mineral dusts, eryoconite granules, and ice algae, plays a crucial role in the changing mass balance through enhancing melt rates in the ablation zone of the glacier.

Influence of Different Surface Modifications on the Photovoltaic Performance and Dark Current of Dye-Sensitized Solar Cells

The TiO2 nanoporous film photoelectrode, as a crucial component of dye-sensitized solar cells, has been investigated. The photovoltaic properties and the dark current were studied by two surface modification methods. One was to apply a compact layer between the conductive glass substrate and nanoporous TiO2 film. Another was to produce TiO2 nanoparticles among the microstructure by TICl4 treatment. A suitable concentration and number of times for TICl4 treatment were found in our experiment. The dark current is suppressed by surface modifications, leading to a significant improvement in the solar cells performance. An excessive concentration of TICl4 will produce more surface states and introduce a larger dark current reversely. The dye is also regarded as a source of charge recombination in dark to some extent, due to an amount of surface protonations introduced by the interracial link in the conductive glass substrate/dye interface and dye/TiO2 interface.