Classes of atmospheric aerosols and their main sources, distributions of tropospheric aerosol by size and mass, their physico-chemical composition and principal optical properties in various spectral bands are described. Stratospheric aerosols in “quiet” and “disturbed” periods after the major volcanic eruptions, their interactions with clouds and of underlying surface radiative properties affe...

Volcanic eruptions demonstrate that our planet is alive and evolving. Take photos of volcanoes around the Earth and you will see that they all look different, but also share important features. Some volcanoes come in perfect conical shapes, while others are much flatter and harder to spot. This is just like humans, some are tall and others are short, or some have dark hair while others have lig...

The controversial claim that El Niño events might be partially caused by radiative forcing due to volcanic aerosols is reassessed. Building on the work of Mann et al., estimates of volcanic forcing over the past millennium and a climate model of intermediate complexity are used to draw a diagram of El Niño likelihood as a function of the intensity of volcanic forcing. It is shown that in the co...

differentiation The process by which planets and satellites develop layers or zones of different chemical and mineralogical composition. flyby Term used to describe the close approach of a spacecraft to a body, without the spacecraft going into orbit around that body. Galilean satellites The four largest satellites of Jupiter (Io, Europa, Ganymede, Callisto), named after their discoverer Galile...

The polarization lidar photometer networking (POLIPHON) method introduced to separate coarse-mode and fine-mode particle properties of Eyjafjallajökull volcanic aerosols in 2010 is extended to cover Saharan dust events as well. Furthermore, new volcanic dust observations performed after the Grimsvötn volcanic eruptions in 2011 are presented. The retrieval of particle mass concentrations require...

Volcanic ash is fragments of magma, and consists of minerals and volcanic glass. These materials in the ash can provide important information on the nature of the magma, because chemical compositions of magma usually show distinct features in each volcano, and because assemblages and compositions of minerals reflect their host melt. Using assemblages and chemical compositions of minerals and gl...

Extreme volcanism on Io results from tidal heating, but its tidal dissipation mechanisms and magma ascent processes are poorly constrained. Here we analyze the distribution of volcanic hotspots and paterae identified within the first 1:15,000,000-scale global geologic map of Io to characterize their patterns of spatial organization. Ionian hotspots correspond to the locations of positive therma...

[1] We present measurements of the phase function and degree of linear polarization for unpolarized incident light as a function of the scattering angle for El Chichón and Pinatubo volcanic ashes at 633 nm. The results are combined and compared with those for Pinatubo at 442 nm and Lokon volcanic ash at 442 and 633 nm [Volten et al., 2001]. The three samples of volcanic ashes consist of micron ...

Shallow-water coral reef ecosystems, particularly those already impaired by anthropogenic pressures, may be highly sensitive to disturbances from natural catastrophic events, such as volcanic eruptions. Explosive volcanic eruptions expel large quantities of silicate ash particles into the atmosphere, which can disperse across millions of square kilometres and deposit into coral reef ecosystems....