[1] This study uses TRMM lightning and radar observations to study the fundamental relationship between precipitation ice mass and lightning flash density. The results indicate that the physical assumptions of precipitation-based charging and mixed phase precipitation development are robust and that on a global scale, the relationship between precipitation ice water path and lightning flash den...

In situ measurements of ice crystal concentrations and sizes made with aircraft instrumentation over the past two decades have often indicated the presence of numerous relatively small (< 50μm diameter) crystals in cirrus clouds. Further, these measurements frequently indicate that small crystals account for a large fraction of the extinction in cirrus clouds. The fact that the instruments used...

The fabrication of Yb 3+ , Tm co-doped oxyfluorophosphate glass-based composites, with green persistent luminescence after being charged near-infrared light, is demonstrated. mechanism responsible for the afterglow illumination unveiled. composite prepared using a modified melting process to limit evaporation fluorine during melting. Intense (blue and ultraviolet) up-conversion emission obtaine...

m a r Terrigenous sediments from Ceara Rise in the western ropical Atlantic Ocean record Pleistocene Amazon Basin cliate variability. Iron oxides and oxyhydroxides in this region riginate mainly from chemically leached Amazon lowland oils. Concentrations of goethite and hematite in the terrignous fraction consistently peak during transitions from lacial to interglacial periods, suggesting an in...

[1] The millimeter wavelength radar backscattering properties at 94 GHz for six nonspherical ice crystals, which include hexagonal column, hollow, plate, bullet rosette, aggregate, and droxtal with 46 maximum dimensions ranging from 2 to 10,500 mm, are investigated using the discrete dipole approximation (DDA) method and Lorenz-Mie theory. It is found that the radar backscattering cross section...

Glaciation has affected the shape of mountain ranges and has induced a global increase in erosion rates during the past 2 m.y. The observed increase in erosion rates appears to vary with latitude, reaching a maximum at mid-latitudes that is particularly well defined in the Southern Hemisphere. Although it is likely that climate played an important role, the processes responsible for such latitu...

Taking advantage of their optical transparency, we clearly observed the third stage infective juveniles (IJs) of Steinernema feltiae freezing under a cryo-stage microscope. The IJs froze when the water surrounding them froze at -2°C and below. However, they avoid inoculative freezing at -1°C, suggesting cryoprotective dehydration. Freezing was evident as a sudden darkening and cessation of IJs'...

The timing of lake ice-out has advanced substantially in many regions of the Northern Hemisphere, however the effects of ice-out timing on lake properties and how they vary regionally remain unclear. Using data from two inter-annual monitoring datasets for a set of three Arctic lakes and one boreal lake, we compared physical, chemical and phytoplankton metrics from two years in which ice-out ti...

The effective shear viscosity and frequency-dependent dynamic oscillatory shear spectra of water containing monovalent or divalent ions (ionic strength 25 mM), confined between mica crystals at 1-2 water molecules thickness, oscillated with twist angle with the period expected for the pseudohexagonal surface lattice. The effective viscosity varied by orders of magnitude as the twist angle was c...