Ice in the Antarctic polar stratosphere

On six occasions during the 1987 Airborne Antarctic Ozone Experiment, the Polar Stratospheric Cloud (PSC) ice crystals were replicated over the Palmer Peninsula at approximately 70 deg South. The sampling altitude was approximately 60 to 65 thousand feet, the temperature range was -83.5 to -72C and the atmosphere was subsaturated in all cases. The collected crystals were predominantly complete and hollow prismatic columns with maximum dimensions up to 217 microns. Evidence of scavenging of submicron particles was detected on several crystals. While the replicated crystal sizes were larger than anticipated, their relatively low concentration results in a total surface area less than one tenth that of the sampled aerosol particles. The presence of large crystals suggest that PSC ice crystals can play a very important role in stratospheric dehydration processes

Antarctic polar stratospheric aerosols: The roles of nitrates, chlorides and sulfates

Nitric and hydrochloric acids have been postulated to condense in the winter polar stratosphere to become an important component of polar stratospheric clouds. One implication is that the removal of NO(y) from the gas phase by this mechanism allows high Cl(x) concentrations to react with O3, because the formation of ClNO3 is inhibited. Contributions of NO3 and Cl to the stratospheric aerosol were determined during the 1987 Airborne Antarctic Ozone Experiment by testing for the presence of nitrates and chlorides in the condensed phase. Aerosol particles were collected on four 500 micron diameter gold wires, each pretreated differently to give results that were specific to certain physical and chemical aerosol properties. One wire was carbon-coated for concentration and size analyses by scanning electron microscopy; X-ray energy dispersive analyses permitted the detection of S and Cl in individual particles. Three more wires were coated with Nitron, barium chloride and silver nitrate, respectively, to detect nitrate, sulfate and chloride in aerosol particles. All three ions, viz., sulfates, nitrates and chlorides were detected in the Antarctic stratospheric aerosol. In terms of number concentrations, the aerosol was dominated by sulfates, followed by chlorides and nitrates. An inverse linear regression can be established between nitrate concentrations and ozone mixing ratio, and between temperature and nitrates

Mount St. Helens aerosol evolution

Stratospheric aerosol samples were collected using a wire impactor during the year following the eruption of Mount St. Helens. Analysis of samples shows that aerosol volume increased for 6 months due to gas-to-particle conversion and then decreased to background levels in the following 6 months

Predicting the Pursuit of Post-Secondary Education: Role of Trait Emotional Intelligence in a Longitudinal Study

Trait Emotional Intelligence (EI) is a constellation of emotional self-perceptions and dispositions related to perceiving, understanding, using, and managing emotions of self and others. Although higher trait EI has been implicated in post-secondary success among university students. There is lack of evidence for whether it predicts the pursuit of post-secondary education (PSE) in emerging adulthood. This was the first study to investigate the role of trait EI in PSE pursuit using a large, nationally-representative sample of Canadian young adults who participated in the National Longitudinal Survey for Children and Youth (NLSCY). Participants in this dataset reported on their PSE status at three biennial waves (age 20–21, 22–23, and 24–25), and completed a four-factor self-report scale for trait EI (Emotional Quotient Inventory: Mini) at ages 20–21 and 24–25. Higher trait EI subscale scores were significantly associated with greater likelihood of PSE participation both concurrently, and at 2- and 4-year follow-ups. Overall, these associations were larger for men than women. The finding that these links persisted over a multi-year period is particularly promising, as it represents an important validation step toward further investment in socioemotional competencies as part of youth development interventions

Transfer von festen, flüssigen und gasförmigen Stoffen aus Vulkanen in die Atmosphäre

Die häufigsten vulkanischen Volatilen sind H2O, CO2, SO3 und Halogene. Zusammensetzung, Menge und Injektionsraten von vulkanischen Gasen und Partikeln in die Troposphäre und Stratosphäre hängen ab von der chemischen Zusammensetzung eines Magmas, dem plattentektonischen Milieu sowie Eruptionsmechanismen und Eruptionsraten. Über 90% der eruptierten Magmen sind basaltischer Zusammensetzung mit niedriger Viskosität, relativ geringen Volatilengehalten und meist niedrigen Eruptionsraten sowie wenig explosiven Eruptionen überwiegend entlang der mittelozeanischen Rücken in großen Wassertiefen. Magmen in Inselbögen und Subduktionszonen an Kontinenträndern sind H2O-reich, in anderen plattentektonischen Milieus überwiegt in basaltischen Magmen CO2. In mafischen Magmen ist CO2 schlecht löslich und kann daher schon mehrere Kilometer unter der Erdoberfläche als Gasphase aus einem Magma entweichen. Felsische (hochdifferenzierte) Magmen, H2O-reich und CO2-arm, eruptieren oft hochexplosiv, insbesondere an Subduktionszonen, und mit hohen Eruptionsraten, z.B. El Chichón (Mexiko, 1982) und Pinatubo (Philippinen, 1991). Ihre Eruptionssäulen (Gas-/Partikelgemische) können bis ca. 40 km Höhe erreichen und sind Hauptlieferant der in die Stratosphäre injizierten Gasmengen

Leaf Characteristics Of Spider Mite Resistant And Susceptible Cultivars Of Pelargonium-X-Hortorum

Volume: 83Start Page: 191End Page: 19

Electron Spin Echo Spectroscopy: A Tool to Probe Structural Properties of Coals

Electron spin echo (e.s.e.) spectroscopy has been used in these laboratories to investigate proton hyperfine interactions in whole coal, separated coal macerals, synthetic lignites and model materials comprising perylene radical ions adsorbed on alumina and silica-alumina catalysts. The e.s.e. technique provides information that is complementary to electron nuclear double resonance in studying such interactions in coal. Coupling constants measured so far in evacuated samples of Illinois No. 6 agree well with models for condensed ring aromatic structures. Analysis of the proton matrix interactions are best fitted by r = 0.75 ± 0.05 nm, Aiso = 0 and n = 40 protons. Matrix interactions from 13C nuclei also are seen. Coupling constants observed in a vitrain component separated from Illinois No. 6 coal are similar to those seen in the whole coal; the fact that the maceral does not exhibit all of the interactions found in whole coal suggests molecular structures to be specific to individual maceral types. Differences in the g-values of macerals may provide a direct, non-destructive route to the analysis of maceral-specific structure