New data on magmatic H2O contents of pantellerites,with implications for petrogenesis and eruptive dynamics at Pantelleria

Infrared spectroscopic analyses of melt inclusions in quartz phenocrysts from pantellerites erupted at Pantelleria, Italy, show that the magmas contained moderate pre-eruptive H₂O contents, ranging from 1.4 to 2.1 wt.%. Melt H₂O concentrations increase linearly with incompatible elements, demonstrating that H₂O contents were not buffered significantly during fractionation by any crystalline or vapor phase. The relatively low H₂O contents of pantellerites are consistent with an origin by partial melting of alkali gabbros rather than fractional crystallization of basalt. Preeruptive H₂O concentrations do not correlate with the volume or explosivity of pantellerite eruptions; decompression history is critical in determining the style of pantellerite (and other) eruptions.     

Distribution of222Rn over the north Pacific: Implications for continental influences

The atmospheric distribution of²²²Rn over the north Pacific is simulated with a three-dimensional chemical tracer model using meteorological input from the NASA-GISS general circulation model (4°×5° resolution). Radon-222 (half-life 3.8 days) is a tracer of continental air. Model results are in good agreement with measurements from ships and aircraft. Strong Asian influence is found throughout the tropospheric column over the north Pacific in spring, reflecting a combination of frequent convection over the continent, strong westerly winds at altitude, and subsidence over the ocean. In summer, the upper troposphere over the north Pacific is heavily affected by deep convection over China; however, Asian influences at the surface are then at their yearly minimum. In winter, strong Asian influence is found near the surface but not at high altitudes. Transport of American air over the Pacific is important only at low latitudes. American sources account for 11% of total²²²Rn in the model at Midway, 30% at Mauna Loa and 59% at Oahu. Results for Hawaii indicate two seasonal peaks of American influence, one in summer and one in winter. The tropical western Pacific is particularly remote from continental influences year round.     

Statistical EOF analysis of spatiotemporal glacier mass-balance variability: a case study of Mittivakkat Gletscher,SE Greenland

An Empirical Orthogonal Function (EOF) variance analysis was performed to map in detail the spatiotemporal variability in individual stake mass-balances (ba) on Mittivakkat Gletscher (MG) – in a region where at present five out of ~20.000 glaciers have mass-balance observations. The EOF analysis suggested that observed ba was summarized by two modes: EOF1 and EOF2 represented 80% (significant) and 6% (insignificant) of the explained variance, respectively. EOF1 captured a decline in ba that was uniformly distributed in space at all stakes. The decline was correlated with albedo observations and air temperature observations from nearby stations. EOF2, however, described variations in ba that were heterogeneously distributed among stakes and associated with local slope and aspect. Low elevation stakes (~<400 m a.s.l.) showed relatively negative (out of phase) correlation and higher elevated stakes relatively positive (in phase) eigenvector correlation values with EOF2. Such relatively negative and positive eigenvector correlation values were present where the constituted of exposed glacier ice or snow cover, respectively. The results from this study show how EOF analyses can provide information on spatiotemporal patterns of glacier mass-balance. Understanding such detailed variabilities in mass-balance on a Greenlandic glacier is of interest because a fifth of the Arctic contribution from glaciers and ice caps to sea-level rise originates from Greenland.     

Mapping the vulnerability of European summer tourism under 2 °C global warming

Summer tourism is one of the most important contributors to the European GDP especially for the southern countries and is highly dependent on the climatic conditions. Changes in average climatic conditions, along with the potential subsequent changes in the physical environment, will pose stress on the favorability of the climate of European destinations for tourism and recreational activities. Here, we study the vulnerability of summer-oriented tourism due to a global temperature increase by 2 °C relative to the preindustrial era. We use a well-defined framework of exposure, sensitivity, and adaptive capacity indicators for a set of plausible climate (RCPs) and socioeconomic (SSPs) combinations. Our result shows that a 2 °C global warming will pose substantial changes to the vulnerability of the European tourism sector. Despite the general increase in exposure, the vulnerability of summer tourism is highly depended on the socioeconomic developments (SSPs). Although exposure is higher for most of the popular southern European destinations like Spain, France, South Italy, southernmost Greece, and Cyprus, they are expected to be less vulnerable than others, under specific SSPs, due to their higher capacity to adapt to a different climate. The capacity to adapt is lower for higher emission scenarios. Substantial changes are also apparent at the subnational level. Countries like France are foreseen to experience very diverse impacts and vulnerabilities within their own territories that will have consequences in terms of domestic tourism. The dynamics of these changes are expected to alter the state of the current European tourism regime.     

The phase curve survey of the irregular saturnian satellites: A possible method of physical classification

During its 2005 January opposition, the saturnian system could be viewed at an unusually low phase angle. We surveyed a subset of Saturn's irregular satellites to obtain their true opposition magnitudes, or nearly so, down to phase angle values of 0.01°. Combining our data taken at the Palomar 200-inch and Cerro Tololo Inter-American Observatory's 4-m Blanco telescope with those in the literature, we present the first phase curves for nearly half the irregular satellites originally reported by Gladman et al. [2001. Nature 412, 163-166], including Paaliaq (SXX), Siarnaq (SXXIX), Tarvos (SXXI), Ijiraq (SXXII), Albiorix (SXVI), and additionally Phoebe's narrowest angle brightness measured to date. We find centaur-like steepness in the phase curves or opposition surges in most cases with the notable exception of three, Albiorix and Tarvos, which are suspected to be of similar origin based on dynamical arguments, and Siarnaq.     

Density Measurements of Shock Compressed Matter Using Short Pulse Laser Diagnostics

In this paper, experimental results on X-ray and proton radiography of shock compressed matter are presented. It has been performed at the Rutherford Appleton Laboratory (RAL) using three long pulse beams to generate a shock wave in a multi-layer foil and a short pulse beam to create either an X-ray or protons source for a transverse radiography. Depending on the probe material (aluminium or carbon foam) a Molybdenum Kα source or a proton beam are used. Density data of the shocked aluminium, in the multimagabar regime are presented.