Carbon and tungsten have been radiated by 3ω-YAG laser in the power density range from 2 to 12J/cm/pulse in a laboratory setup with the main objective of investigating the behavior of cluster/aerosol formation from colliding ablation plumes. Direct ion mass spectrometry of colliding carbon plumes has identified Cn-clusters including C, C2,C3,C4 and C5. The formation of these Cn-cluster ions has...

The SPIRALE and SWIR balloon-borne instruments were launched in the Arctic polar region (near Kiruna, Sweden, 67.9 N–21.1 E) during summer on 7 and 24 August 2009 and on 14 August 2009, respectively. The SPIRALE instrument performed in situ measurements of several trace gases including CO and O3 at altitudes between 9 and 34 km, with very high vertical resolution (∼ 5 m). The SWIR-balloon instr...

Normalized excess mixing ratios (NEMRs), also known as enhancement ratios, are a common way to characterize plumes of pollution in atmospheric research. As single-source pollutant plumes disperse in the atmosphere, they are diluted by mixing with the adjacent background air. Changes in the composition of this background air can cause large changes to the NEMR that is subsequently measured by re...

The dynamics of electron beam ablation plumes have been characterized through the application of dye laser resonance absorption photography. The ablation of fused silica by a channelspark electron beam was studied by probing the near-ground state, 3p D24s P neutral Si transition at 288.158 nm. Necessary background gases ~Ar or N2) were tested at pressures of 15 or 30 mTorr. A two-lobed, Si atom...

We propose a new modelling framework suitable for the description of atmospheric convective systems as a collection of distinct plumes. The literature contains many examples of models for collections of plumes in which strong simplifying assumptions are made, a diagnostic dependence of convection on the large-scale environment and the limit of many plumes often being imposed from the outset. So...

[1] Enceladus’ south polar region has a large heat flux, 55–110 mW m , that is spatially associated with cryovolcanic and tectonic activity. Tidal dissipation and vigorous convection in the underlying ice shell are possible sources of heat, however, prior predictions of the heat flux carried by stagnant lid convection range from Fconv 15 to 30 mW m , too low to explain the observed heat flux. T...

Pollution of coastal regions of the Great Barrier Reef World Heritage Area (GBRWHA) is dominated by river discharge associated with agricultural development of the adjacent catchments. Runoff of sediment, nutrients and pesticides has sharply increased since European settlement. Since 1991 plumes from river discharge entering the GBRWHA have been mapped by aerial mapping of plume edges and conce...

Hall thrusters are an attractive form of electric propulsion that are being cleveloped to replace chemical systems for many on orbit propulsion tasks on communications satellites. A major concern in the use of these devices is the possible damage their plumes may cause to the host spacecraft. In this paper, the present status of computer modeling of Hall thruster plumes is reviewed in the conte...

The interaction of turbulent plumes is examined in the context of building ventilation flows. Recent models for natural ventilation have been based on simplified treatment of the heat sources in a ventilated enclosure. These models treat buoyancy sources as plumes and assume that they do not interact. To improve the applicability of these models to buildings we examine the effects of plume-plum...

S U M M A R Y Since W. J. Morgan proposed that intraplate volcanism at some Pacific hotspots is caused by hot plumes rising from the lower mantle, geophysicists have been actively pursuing physical evidence for mantle plumes. Several seismic studies have mapped low-velocity anomalies below a number of hotspots. However, the association of low-velocity structures with plume tails has remained co...