Jupiter: New retrieved thermal profiles and ammonia distributions

New thermal profiles of Jupiter are retrieved from recent far infrared spectral measurements and for H₂ mixing ratios varying from 0.8 to 0.94. The effective temperature corresponding to the inferred thermal profile is 123.15 ± 0.35°K. Far-infrared brightness temperature spectra computed from these profiles are compared to experimental data including measurements made at high spectral resolution in the NH₃ν₂ band at 10 μm and in NH₃ pure rotational bands between 40 and 110 μm. It is found that a strong depletion of NH₃ does occur in the Jovian stratosphere and that ammonia seems to be undersaturated in the upper troposphere.     

The intermediate anomaly

A Sundman time transformation of the form $$dt = cr^n ds$$ , wheren=3/2 andc is a constant, is integrated analytically for Keplerian motion. The integral involves an elliptic integral of the first kind. The variable s is called theintermediate anomaly.     

The structure of the broad line region in Fairall 9

We find that the profile changes observed for the UV emission lines L,Civ 1549, and MgIII 2798, in the Seyfert 1 galaxy Fairall 9 occur mainly near the line centre for L andCiv and in the wings for MgIII. These results indicate that the broad line region (BLR) has a complex structure, possibly with non-spherical components.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

Surface-layer flow in complex terrain: Comparison of models and full-scale observations

Four models of surface boundary-layer flow in complex terrain are compared with observations made at Blashaval Hill, North Uist, Scotland. The field experiment is described by Mason and King (1985). Three of the models are derived from the two-dimensional theory of Jackson and Hunt (1975) and are described in Mason and King (1985), Walmsley et al. (1986) and Troen and Petersen (1989). The fourth is a mass-consistent code based on Traci et al. (1979). The model results are in good agreement with each other and are generally within the observed range of variation ( ~ ± 16%) in normalized wind speed. For most wind direcions (7 of 11), model results of normalized wind speed at the summit were within 7% of the observed mean values. For some wind directions, calculations using the Guidelines of Walmsley et al. (1989) suggested that variations in surface roughness were important. This led us to apply one of our models incorporating nonuniform surface roughness. The lack of significant improvement for cases when water lay upstream of Blashaval Hill is attributed to compensating changes at summit and reference sites and to very local effects on the wind data. Sensitivity to topography lying to the west and northwest of Blashaval was also investigated. Results suggested an influence from those distant topographic features for some wind directions. When those features were incorporated, maximum errors in normalized wind speed at the summit were reduced from 18 to 13%.     

Hydrocarbons in surficial sediments from the Scotian Shelf

Surface sediments from 20 stations on the Scotian Shelf, collected on a transect from Halifax to Emerald Bank and around Sable Island, have been analyzed for hydrocarbon content and composition by gas chromatography and fluorescence spectrophotometry. Some samples were taken near abandoned exploratory drilling sites in the Sable Island area. Hydrocarbons appear to be mainly derived from biogenic terrestrial sources as evidenced by an inverse correlation of concentration with increasing distance from the mainland and a strong odd carbon preference in the n-alkanes. Contribution from petroleum sources, while minor, was most noticeable between Halifax and Emerald Bank. There is also evidence that the hydrocarbon composition at abandoned exploratory drilling sites has been slightly altered.     

Amino acid composition of organic matter associated with carbonate and non-carbonate sediments

Amino acids comprise from 15 to 36% by weight of humic substances from carbonate and non-carbonate sediments. Humic and fulvic acids extracted from carbonate sediments are characterized by an amino acid composition consisting primarily of the acidic amino acids, aspartic and glutamic acid. Humic substances from non-carbonate sediments have a distinctly different amino acid composition consisting primarily of glycine and alanine. Amino acid analyses of various molecular weight fractions of fulvic acids extracted from carbonates show that lower molecular weight fractions have appreciably higher relative abundances of the acidic amino acids compared to higher molecular weight fractions. Based on typical values for carboxyl group content in humic substances, acidic amino acids may be a significant contributor of these functional groups. Carbonate surfaces appear to selectively adsorb aspartic acid-enriched organic matter while non-carbonates do not have this property.     

An experimental study of anorthosite dissolution in lunar picritic magmas: Implications for crustal assimilation processes

Experiments characterizing the kinetics of anorthosite dissolution in lunar picritic magmas (very low-Ti, low-Ti, and high-Ti picritic glasses) were conducted at 0.6 GPa and 1250-1400 °C using the dissolution couple method. Reaction between the anorthosite and lunar picritic magmas at 1250-1300 °C produced a spinel + melt layer. Reaction between the anorthosite and an olivine-saturated low-Ti magma at 1250-1300 °C produced a crystal-free region between the spinel + melt layer and the olivine-saturated magma. The anorthosite dissolution experiments conducted at 1400 °C simply dissolved anorthosite and did not result in a crystal-bearing region. The rate of anorthosite dissolution strongly depends on temperature and composition of the reacting melt. Concentration profiles that develop during anorthosite dissolution are nonlinear and extend from the picritic glass compositions to anorthite. These profiles feature a large and continuous variation in melt density and viscosity from the anorthosite-melt interface to the initial picritic magmas. In both the low-Ti and high-Ti magmas the diffusive fluxes of TiO₂, Al₂O₃, and SiO₂ are strongly coupled to the concentration gradients of CaO and FeO. Anorthosite dissolution may play an important role in producing the chemical variability of the lunar picritic magmas, the origin of spinel in the lunar basalts and picritic glasses, and the petrogenesis of the high-Al basalts.     

GGR Critical Review of Analytical Developments in 2004–2005

In 2005 Geostandards and Geoanalytical Research embarked upon a new initiative for its readers. Key researchers in various fields of geoanalytical technique development and their application were identified and invited to provide reviews pertinent to their expertise. As noted in the first of these publications "…instead of revisiting the historical context or decades of development in each analytical technique, the goal here has been to capture a snapshot of "hot topics" across a range of fields as represented in the… literature" (Hergt et al . 2005). Rather than prepare an annual review, a decision was taken earlier this year to provide a biennial summary of progress and accomplishments, in this case for the years 2004–2005. The principal techniques employed in Earth and environmental sciences are covered here, and include laser ablation and multicollector ICP-MS, ICP-AES, thermal ionisation and secondary ion mass spectrometry, as well as neutron activation analysis, X-ray fluorescence and atomic absorption spectrometry. A comprehensive review of the development of reference materials, often essential to these techniques, is also provided. The contributions assembled serve both to keep readers informed of advances they may be unfamiliar with, but also as a means of showcasing examples of the breadth and depth of work being conducted in these fields.