Meteorological and glaciological analyses are integrated to examine the precipitation trends during the last three decades over the ice sheets covering Antarctica and Greenland. For Antarctica, the best data source is provided by glaciologicallymeasured trends of snow accumulation, and for limited sectors of East Antarctica consistency with precipitation amounts calculated from the atmospheric ...

Recrystallization rate of ice crystals in 33% sucrose solutions, a model frozen dessert, was measured in the presence of antifreeze protein Type I (AFP type I) at -10°C, which is relevant to practical storage or distribution temperature of frozen dessert. The concentrations of AFP type I were set to 0.01, 0.1, and 1g/ml, respectively. Ice crystals during recrystallization process were observed...

Measurements in nascent ice forming regions are very rare and help understand cirrus cloud formation and the interactions of trace gases with ice crystals. A cirrus cloud has very likely been probed in its formation stage with in-situ and remote sensing instruments onboard the high altitude research aircraft Geophysica M55 in the tropical 5 upper troposphere. Besides microphysical and optical p...

Data collected by the National Center for Atmospheric Research S-band polarimetric radar (S-Pol) during the Terrain-Influenced Monsoon Rainfall Experiment (TiMREX) in Taiwan are analyzed and used to infer storm microphysics in the ice phase of convective storms. Both simultaneous horizontal (H) and vertical (V) (SHV) transmit polarization data and fast-alternating H and V (FHV) transmit polariz...

acterization of Arctic ice cloud properties observed during ISDAC. HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destin...

[1] Frost flowers are ice crystals that grow on refreezing sea ice leads in Polar Regions by wicking brine from the sea ice surface and accumulating vapor phase condensate. These crystals contain high concentrations of mercury (Hg) and are believed to be a source of reactive halogens, but their role in Hg cycling and impact on the fate of Hg deposited during atmospheric mercury depletion events...

Understanding the freezing of salt solutions near solid surfaces is important in many scientific fields. Here we use sum frequency generation (SFG) spectroscopy to study the freezing of a NaCl solution next to a sapphire substrate. During cooling we observe two transitions. The first corresponds to segregation of concentrated brine next to the sapphire surface as we cool the system down to the ...

Biological ice nucleators (IN) function as catalysts for freezing at relatively warm temperatures (warmer than -10 degrees C). We examined the concentration (per volume of liquid) and nature of IN in precipitation collected from Montana and Louisiana, the Alps and Pyrenees (France), Ross Island (Antarctica), and Yukon (Canada). The temperature of detectable ice-nucleating activity for more than...

A technique for detecting large hydrometeors at high altitudes is described here and applied to the Upper Atmosphere Research Satellite/Microwave Limb Sounder (UARS/MLS) 203-GHz radiance measurements at tangent pressures between 200 and 46 hPa. At these tangent pressures the radiances remain optically thin and cloudy-sky radiances are brighter than normal clear-sky cases. Unlike infrared/visibl...

[1] A thermomechanical ice sheet model (ISM) is used to investigate the sensitivity of the Laurentide and Fennoscandian ice sheets to tropical sea surface temperature (SST) perturbations during deglaciation. The ISM is driven by surface temperature and precipitation fields from three different atmospheric general circulation models (AGCMs). For each AGCM, the responses in temperature and precip...