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High ice water content (IWC) regions in mesoscale convective systems (MCSs) are a potential threat to commercial aviation, as they are suspected to cause in-service engine power-loss events and air data probe malfunctions. To investigate this, the high-altitude ice crystals (HAIC)/high ice water content (HIWC) projects set up a first field campaign in Darwin (Australia) in 2014. The airborne instrumentation was selected to provide the most accurate measurements of both the bulk total water content (TWC), using a specially developed isokinetic evaporator, and the individual ice crystals properties, using particle imaging probes. This study focuses on determining the size ranges of ice crystals responsible for the mass in high IWC regions, defined here as cloud regions with IWC greater than 1.5 g m-3. It is shown that for high IWC areas in most of the encountered MCSs, median mass diameters (MMDs) of ice crystals range from 250 to 500 μm and decrease with increasing TWC and decreasing temperature. At the same time, the mass contribution of the smallest crystals (below 100 μm) remains generally low (below 15%). In contrast, data from two flight missions in a long-lasting quasi-stationary tropical storm reveal that high IWC values can also be associated with MMDs in the range 400-800 μm and peak values of up to 2 mm. Ice crystal images suggest a major growth contribution by vapor deposition (columns, capped columns) even for such larger MMD values. [ABSTRACT FROM AUTHOR]

The radar network deployed in southern France during the first special observing period (SOP 1) of the Hydrological Cycle in the Mediterranean Experiment (HyMeX) was designed to precisely document the 3D structure of moist upstream flow impinging on complex terrain as a function of time, height, and along-barrier distance, and surface rainfall patterns associated with orographic precipitation events. This deployment represents one of the most ambitious field experiments yet, endeavoring to collect high-quality observations of thunderstorms and precipitation systems developing over and in the vicinity of a major mountain chain. Radar observations collected during HyMeX represent a valuable, and potentially unique, dataset that will be used to improve our knowledge of physical processes at play within coastal orographic heavy precipitating systems and to develop, and evaluate, novel radar-based products for research and operational activities. This article provides a concise description of this radar network and discusses innovative research ideas based upon preliminary analyses of radar observations collected during this field project with emphasis on the synergetic use of dual-polarimetric radar measurements collected at multiple frequencies. [ABSTRACT FROM AUTHOR]

The article focuses on the Cloudnet project which aims to provide a systematic evaluation of clouds in forecast models. Clouds and their associated microphysical processes strongly regulate radiative transfer and the hydrological cycle. The data products in the Cloudnet processing chain are summarized. Cloudnet involved six modeling centers. Some of the instruments that are required to provide continuous long-term vertical profiles of cloud fraction, liquid water content and ice water contents suitable for evaluating models are described.

This report describes the ultrastructural characteristics of a Poncet-Spiegler tumor (cylindroma, turban tumor). This tumor was made tip of two cell types and showed a ductal differentiation. Cells bordering duct-like structures were joined together by innumerable desmosomes, especially in places where the cell membranes were markedly invaginated. The arguments in favor of an eccrine or an apocrine for the origin of this sweat gland tumor are discussed. [ABSTRACT FROM AUTHOR]