Rosetta-Alice Observations of Exospheric Hydrogen and Oxygen on Mars

The European Space Agency's Rosetta spacecraft, en route to a 2014 encounter with comet 67P/Churyumov-Gerasimenko, made a gravity assist swing-by of Mars on 25 February 2007, closest approach being at 01:54UT. The Alice instrument on board Rosetta, a lightweight far-ultraviolet imaging spectrograph optimized for in situ cometary spectroscopy in the 750-2000 A spectral band, was used to study the daytime Mars upper atmosphere including emissions from exospheric hydrogen and oxygen. Offset pointing, obtained five hours before closest approach, enabled us to detect and map the HI Lyman-alpha and Lyman-beta emissions from exospheric hydrogen out beyond 30,000 km from the planet's center. These data are fit with a Chamberlain exospheric model from which we derive the hydrogen density at the 200 km exobase and the H escape flux. The results are comparable to those found from the the Ultraviolet Spectrometer experiment on the Mariner 6 and 7 fly-bys of Mars in 1969. Atomic oxygen emission at 1304 A is detected at altitudes of 400 to 1000 km above the limb during limb scans shortly after closest approach. However, the derived oxygen scale height is not consistent with recent models of oxygen escape based on the production of suprathermal oxygen atoms by the dissociative recombination of O2+.Comment: 17 pages, 8 figures, accepted for publication in Icaru

Wet scavenging of soluble gases in DC3 deep convective storms using WRF-Chem simulations and aircraft observations

We examine wet scavenging of soluble trace gases in storms observed during the Deep Convective Clouds and Chemistry (DC3) field campaign. We conduct high-resolution simulations with the Weather Research and Forecasting model with Chemistry (WRF-Chem) of a severe storm in Oklahoma. The model represents well the storm location, size, and structure as compared with Next Generation Weather Radar reflectivity, and simulated CO transport is consistent with aircraft observations. Scavenging efficiencies (SEs) between inflow and outflow of soluble species are calculated from aircraft measurements and model simulations. Using a simple wet scavenging scheme, we simulate the SE of each soluble species within the error bars of the observations. The simulated SEs of all species except nitric acid (HNO_3) are highly sensitive to the values specified for the fractions retained in ice when cloud water freezes. To reproduce the observations, we must assume zero ice retention for formaldehyde (CH_2O) and hydrogen peroxide (H_2O_2) and complete retention for methyl hydrogen peroxide (CH_3OOH) and sulfur dioxide (SO_2), likely to compensate for the lack of aqueous chemistry in the model. We then compare scavenging efficiencies among storms that formed in Alabama and northeast Colorado and the Oklahoma storm. Significant differences in SEs are seen among storms and species. More scavenging of HNO_3 and less removal of CH_3OOH are seen in storms with higher maximum flash rates, an indication of more graupel mass. Graupel is associated with mixed-phase scavenging and lightning production of nitrogen oxides (NO_x), processes that may explain the observed differences in HNO_3 and CH_3OOH scavenging

Gestão financeira de uma cooperativa agroindustrial: práticas de gerenciamento e análise financeira

The financial statements are meant to help managers and users of accounting information in the decisionmaking process. The cooperative has taken more prominence in the financial system. This article aims to analyze and demonstrate the economic and financial performance of an Agroindustrial Cooperative of Santa Catarina in the city of Chapecó. The analysis was based on the financial statements, balance sheet and statement of leftovers or cooperative losses, between the years 2012 and 2014. To achieve the goal and an exploratory qualitative research was carried out in the statements of the studied cooperative. Knowing this, it is suggested that aspects of monitoring, control, evaluation and improvement of the results are of great importance, because many cooperatives do not provide adequate care, which must be controlled in real time with strategic planning.As demonstrações contábeis têm a função de auxiliar os gestores e usuários da informação contábil no processo de tomada de decisão. O cooperativismo tem tomado cada vez mais destaque no Sistema Financeiro Nacional. Esse artigo tem como objetivo analisar e demonstrar o desempenho econômico e financeiro de uma Cooperativa Agroindustrial de Santa Catarina na cidade de Chapecó. A análise teve como base as demonstrações contábeis, balanço patrimonial e demonstração de sobras ou perdas da cooperativa, entre os anos de 2012 e 2014. Para alcançar o objetivo foi realizada uma pesquisa exploratória e qualitativa nas demonstrações da cooperativa estudada. Sabendo-se disso, é sugerido que os aspectos de acompanhamento, controle, avaliação e aprimoramento dos resultados são de elevada importância, pelo fato de várias cooperativas não proporcionarem adequada atenção, o qual deve ser controlado em tempo real com o planejamento estratégico

Estudo da Interação de Uma Cooperativa Habitacional com a Sociedade

The interaction between cooperative organizations and of solidarity economy and the society is the principal focus of this assignment, emphasizing the influence that this kind of cooperation gets, becoming a mechanism of transformation and social inclusion, in addiction, what these interactions are made of. For this, we chose a housing cooperative. This research is classified as qualitative case study, getting done through semi-structured interviews with the President, the Pedagogic Directory and a cooperating person. The results reveal that the cooperative principles are rooted in the activities of the cooperative, especially the principles of self-management, free membership and education. Although this organization had been in difficulties in its beginning, results demonstrated that society keeps opening space to the cooperativism ideals. Join the cooperative shows that it is possible to have personal and social development, which serves as the impetus and motivation to expand the activities of the cooperative, it is necessary to be a change in the mindset of society so that the cooperative thinking and the way of organize the cooperatives can gain space in people’s lives.Com o intuito de compreender como se dá a interação das organizações cooperativas e de economia com a sociedade, e quais são os elementos que constituem essa integração, o presente artigo foi desenvolvido. Para isso, escolheu-se uma cooperativa habitacional. A pesquisa classifica-se como um estudo de caso qualitativo. A principal técnica de coleta de dados foi a entrevista semiestruturada, realizada com o Presidente, o Diretor Pedagógico e uma cooperada. Os resultados revelam que os princípios do cooperativismo estão enraizados nas atividades da cooperativa, principalmente os princípios da autogestão, livre adesão e o da educação. Apesar das diversas situações que a cooperativa passou como problemas de sustentabilidade financeira, os resultados mostraram que se vem criando e dedicando cada vez mais espaço dentro da sociedade para os ideais cooperativistas. Aderir à cooperativa mostra que é possível ter desenvolvimento pessoal e social, o que serve como impulso e motivação para expandir as atividades da cooperativa, para isso é necessário haver uma mudança na forma de pensar da sociedade para que o pensamento cooperativista e a forma de se organizar do cooperativismo possam ganhar espaço na vida das pessoas

The Distance to SN 1999em in NGC 1637 from the Expanding Photosphere Method

We present 30 optical spectra and 49 photometric epochs sampling the first 517 days after discovery of supernova (SN) 1999em, and derive its distance through the expanding photosphere method (EPM). SN 1999em is shown to be a Type II-plateau (II-P) event, with a photometric plateau lasting until about 100 days after explosion. We identify the dominant ions responsible for most of the absorption features seen in the optical portion of the spectrum during the plateau phase. We find the distance to SN 1999em to be D = 8.2 +/- 0.6 Mpc, with an explosion date of 5.3 +/- 1.4 days before discovery. We examine potential sources of systematic error in EPM-derived distances, and find the most significant to result from uncertainty in the theoretical modeling of the flux distribution emitted by the SN photosphere (i.e., the ``flux dilution factor''). We compare previously derived EPM distances to 5 SNe II in galaxies for which a recently revised Cepheid distance exists from the HST Key Project and find D(Cepheids) / D(EPM) = 0.96 +/- 0.09. Finally, we investigate the possible use of SNe II-P as standard candles and find that for 8 photometrically confirmed SNe II-P with previously derived EPM distances and SN 1999em, the mean plateau absolute brightness is M_V(plateau) = -16.4 +/- 0.6 mag, implying that distances good to ~30% (1-sigma) may be possible without the need for a complete EPM analysis. At M_V(plateau) = -15.9 +/- 0.2 mag, SN 1999em is somewhat fainter than the average SN II-P. The general consistency of absolute SNe II-P brightness during the plateau suggests that the standard candle assumption may allow SNe II-P to be viable cosmological beacons at z > 2.Comment: 79 pages, 26 figures, accepted for publication in the Publications of the Astronomical Society of the Pacifi

Effects of Scavenging, Entrainment, and Aqueous Chemistry on Peroxides and Formaldehyde in Deep Convective Outflow over the Central and Southeast U.S.

Deep convective transport of gaseous precursors to ozone (O3) and aerosols to the upper troposphere is affected by liquid- and mixed-phase scavenging, entrainment of free tropospheric air, and aqueous chemistry. The contributions of these processes are examined using aircraft measurements obtained in storm inflow and outflow during the 2012 Deep Convective Clouds and Chemistry (DC3) experiment combined with high resolution (dx <= 3 km) WRF-Chem simulations of a severe storm, an airmass storm, and a mesoscale convective system (MCS). The simulation results for the MCS suggest that formaldehyde (CH2O) is not retained in ice when cloud water freezes, in agreement with previous studies of the severe storm. By analyzing WRF-Chem trajectories, the effects of scavenging, entrainment, and aqueous chemistry on outflow mixing ratios of CH2O, methyl hydroperoxide (CH3OOH), and hydrogen peroxide (H2O2) are quantified. Liquid-phase microphysical scavenging was the dominant process reducing CH2O and H2O2 outflow mixing ratios in all three storms. Aqueous chemistry did not significantly affect outflow mixing ratios of all three species. In the severe storm and MCS, the higher than expected reductions in CH3OOH mixing ratios in the storm cores were primarily due to entrainment of low background CH3OOH. In the airmass storm, lower CH3OOH and H2O2 scavenging efficiencies (SEs) than in the MCS were partly due to entrainment of higher background CH3OOH and H2O2. Overestimated rain and hail production in WRF-Chem reduces the confidence in ice retention fraction values determined for the peroxides and CH2O

Early to Late Holocene Surface Exposure Ages From Two Marine-Terminating Outlet Glaciers in Northwest Greenland

Terrestrial chronologies from southern Greenland provide a detailed deglacial history of the Greenland Ice Sheet (GIS). The northern GIS margin history, however, is less established. Here we present surface exposure ages from moraines associated with two large outlet glaciers, Petermann and Humboldt, in the northwestern sector of the GIS. These moraine chronologies indicate a Little Ice Age advance of the ice sheet margin before similar to 0.3 ka and a possible equivalent advance of similar magnitude prior to similar to 2.8 ka. An early Holocene moraine at Humboldt Glacier was abandoned by 8.3 +/- 1.7 ka and is contemporaneous with other moraines deposited along the entire western GIS margin. This widespread ice margin stability between similar to 9 and 8 ka indicates that while this margin was influenced by warming atmospheric temperatures during the early Holocene, the warming was likely overprinted with the effect of the abrupt climate cooling at 9.3 and 8.2 ka. Plain Language Summary The global climate is warming, and the Greenland Ice Sheet is responding. A more complete understanding of this process is needed to better predict its future response to climate change. We determine how the ice sheet changed following the last ice age in northwest Greenland. The northwest sector of the ice sheet retreated to the coast by similar to 10,000 years ago during a period of warming atmospheric temperatures. About 8,300 years ago the ice stopped retreating despite relatively high atmospheric temperatures. A similar standstill occurred in areas along western Greenland between similar to 9,000 and 8,000 years ago. This suggests that despite the long-term warming, well-known abrupt cooling events that occurred in the region at this time influenced the ice sheet margin and temporarily stopped the long-term pattern of ice retreat. The ice sheet retreated after 8,300 years ago and then advanced during the latest cold period, the Little Ice Age (similar to 350-1850 CE), in a fashion similar to elsewhere in Greenland. Our study finds that the Greenland Ice Sheet margins are sensitive to both long-term (>1,000 years) and short-term (<100 years) atmospheric temperature changes. This sensitivity of the ice margin has important implications when assessing ongoing and future ice loss today