bluuebunny/crossref_metadata_2025 huggingface dataset:
Negotiating candidacy: ethnic minority seniors' access to care
Authors: KOEHN SHARON
Published: April 2009

The ‘Barriers to Access to Care for Ethnic Minority Seniors’ (BACEMS) study in Vancouver, British Columbia, found that immigrant families torn between changing values and the economic realities that accompany immigration cannot always provide optimal care for their elders. Ethnic minority seniors further identified language barriers, immigration status, and limited awareness of the roles of the health authority and of specific service providers as barriers to health care. The configuration and delivery of health services, and health-care providers' limited knowledge of the seniors' needs and confounded these problems. To explore the barriers to access, the BACEMS study relied primarily on focus group data collected from ethnic minority seniors and their families and from health and multicultural service providers. The applicability of the recently developed model of ‘candidacy’, which emphasises the dynamic, multi-dimensional and contingent character of health-care access to ethnic minority seniors, was assessed. The candidacy framework increased sensitivity to ethnic minority seniors' issues and enabled organisation of the data into manageable conceptual units, which facilitated translation into recommendations for action, and revealed gaps that pose questions for future research. It has the potential to make Canadian research on the topic more co-ordinated.
The welfare of Sweden's old-age pensioners in times of bust and boom from 1990
Authors: GUSTAFSSON BJÖRN , JOHANSSON MATS , PALMER EDWARD
Published: April 2009

This study analyses the development of the economic wellbeing of Swedes aged 65 years and older from 1990. This period was characterised by Sweden's deepest and most prolonged recession since the Great Depression, but was then followed by buoyant growth. In a series of interventions from 1991 through to 1998, pensions were cut and their full price indexation abandoned. In spite of these dramatic measures, this study shows that pensioners fared better than the working-age population, but also that poverty among older Swedes increased in absolute terms. During the following years of rapid economic growth, in contrast, the growth in pensioners' income fell behind that of workers and their relative poverty increased. The analysis shows that the limited resources of many older Swedes put them close to a social poverty line. The study also shows that income inequality among older Swedes has grown with the increasing importance of capital income for the better off. We conclude that the increasing gap between better-off and worse-off older people raises issues about the future provision of expenditures on public services for them. The paper concludes that, overall, poverty among older people in Sweden remains low by international standards and that the Swedish welfare state has maintained its resilience.
Modernising social care services for older people: scoping the United Kingdom evidence base
Authors: JACOBS SALLY , XIE CHENGQIU , REILLY SIOBHAN , HUGHES JANE , CHALLIS DAVID
Published: April 2009

In common with other developed countries at the end of the 20th century, modernising public services was a priority of the United Kingdom (UK) Labour administration after its election in 1997. The modernisation reforms in health and social care exemplified their approach to public policy. The authors were commissioned to examine the evidence base for the modernisation of social care services for older people, and for this purpose conducted a systematic review of the relevant peer-reviewed UK research literature published from 1990 to 2001. Publications that reported descriptive, analytical, evaluative, quantitative and qualitative studies were identified and critically appraised under six key themes of modernisation: integration, independence, consistency, support for carers, meeting individuals' needs, and the workforce. This paper lists the principal features of each study, provides an overview of the literature, and presents substantive findings relating to three of the modernisation themes (integration, independence and individuals' needs). The account provides a systematic portrayal both of the state of social care for older peoplepriorto the modernisation process and of the relative strengths and weaknesses of the evidence base. It suggests that, for evidence-based practice and policy to become a reality in social care for older people, there is a general need for higher quality studies in this area.
Ill, worried or worried sick? Inter-relationships among indicators of wellbeing among older people in Sweden
Authors: HALLERÖD BJÖRN
Published: April 2009

This study examined the associations between a large set of health indicators and wellbeing among older people (aged 66 or more years) in Sweden. The data were drawn from the Swedish Panel Survey of Ageing and the Elderly (PSAE), with variables covering information about health, daily activities, social interaction, anxieties and worries, and economic hardship. A series of confirmative factor analyses were used to reveal if and how indicators of living conditions could be subdivided into latent factors, and several socio-economic and socio-demographic variables were used as their predictors. Differences between men and women and between a number of age groups of old people were systematically scrutinised. The preferred representation of the data was a nested model that identified one global factor, which related to all manifest indicators, and three residual factors that measured the specific experiences of physical impairment, psychosocial distress and economic difficulties. The findings improve our understanding of the relationships between indicators of health and wellbeing and the various latent dimensions that simultaneously affect response patterns. More importantly, they also facilitate our understanding of older people's wellbeing and assists the interpretation of single, commonly used indicators such as subjective health.
Lower Devonian dalmanitid trilobites of the Prague Basin (Czech Republic)
Authors: Budil Petr , Hörbinger František , Mencl Robert
Published: April 2009

A revision of the Lower Devonian dalmanitid trilobites of the Prague Basin (Czech Republic) is presented. The subfamily Odontochilinae Šnajdr is considered a synonym of Dalmanitidae Vogdes. Twenty-one previously and five newly described (three in open nomenclature) species and subspecies occur in the Prague Basin from the lowermost Pragian (one problematic specimen possibly comes from the uppermost Lochkovian) to the Lower Emsian; the last questionable record is from the Upper Emsian. The species have been assigned to four genera and subgenera: Odontochile Hawle & Corda, Reussiana Šnajdr, Zlichovaspis (Zlichovaspis) Přibyl & Vaněk and Zlichovaspis (Devonodontochile) Šnajdr. These trilobites are considered as scavengers or opportunistic predators, living most of their lives as vagrant benthos burying in the muddy substrate to find organic remains. The first undoubted adult-like meraspid specimens are described.
Geochemical investigation of an unusual alteration profile developed at the base of a Carboniferous lava flow, Isle of Bute, Scotland
Authors: Young Grant M.
Published: April 2009

An alteration zone at the base of a Carboniferous lava flow on the island of Bute resembles modern and ancient weathering profiles, but it is ‘upside down’ in the sense that alteration is most intense at the base and decreases upwards. Values for a Chemical Index of Alteration (CIA) increase from fresh lava and corestones downwards to fine-grained structureless material. The altered material is Mg- and Cu-rich, possibly as a result of migration of these elements from underlying sediments. Rare earth elements (REE) display considerable and systematic mobility and fractionation. In general heavy rare earth elements (HREE) are concentrated during alteration, whereas the light rare earth elements (LREE) are lost. Mobility of the REE appears to be related to atomic weight, with La (the lightest REE) being the most depleted through to Lu, which is the most concentrated REE in the highly altered material. Similar systematic fractionation is shown by some weathering profiles developed on mafic igneous rocks. Movement of water into the volcanic rocks was probably driven by a steep thermal gradient between the hot lava and its sedimentary substrate.
Late Ordovician trilobites from northwest Iran and their biogeographical affinities
Authors: Karim Talia S.
Published: April 2009

A diverse, previously undescribed trilobite fauna from northwest Iran sheds new light on the Early Palaeozoic geography of the Alborz terrane. The structural history of the Alborz region is well known, though faunal data for the area are sparse, especially for the Ordovician. Trilobites, brachiopods, conodonts, bryozoans and echinoderms occur in a red grainstone/packstone near the village of Tatavrud, 35 km southwest of Bandar-e-Anzali. The fossils indicate a Late Ordovician age, although lithologically similar outcrops in northern Iran have previously been considered Silurian. Trilobite genera occurring include Trinodus, Geragnostus, Illaenus, Panderia, Phorocephala, Ovalocephalus, Dicranopeltis, Symphysops, Cyclopyge, and Sphaerexochus. Similar assemblages have been reported from the Late Ordovician of Ireland, Spain, Poland, Norway, northwest China, Kazakhstan and the Turkistan–Alai Ridge (Uzbekistan–Kyrgyzstan border). Reconstructions of Late Ordovician geography place the Alborz terrane near the eastern margin of Gondwana, but there is doubt as to its precise location. Some workers have considered it part of the margin while others have considered it a separate terrane. Several species present, including Mezzaluna tatavrudensis n. sp. and Phorocephala cf. ulugtana (Petrunina, 1975) are very similar to taxa described from the Turkistan–Alai Ridge. In addition, the isocolid genus Paratiresias has only been reported from Iran, the Turkistan–Alai Ridge and northwest China. The presence of these taxa indicates that the Alborz terrane was in close proximity to the eastern margin of Gondwana at this time.
Identifikation abweichender Antwortmuster im „Fragebogen zur Evaluation von Psychotherapieverläufen” mithilfe der Rasch-Analyse
Authors: Schürch Eva , Lutz Wolfgang , Böhnke Jan R.
Published: April 2009

Zusammenfassung. Theoretischer Hintergrund: Unbemerkte abweichende Antwortmuster in Fragebogendaten führen zu Datenverzerrungen und falschen diagnostischen Entscheidungen. Für manche Fragebogen gibt es Prüfalgorithmen, welche den Datensatz systematisch nach vordefinierten Antworten absuchen und diese herausfiltern. Für die Mehrzahl der gängigen Messinstrumente in der Psychologie gibt es jedoch keine einfache Möglichkeit, solche Antwortmuster zu identifizieren. Fragestellung: Basierend auf der Rasch-Analyse wird eine Methode zur Identifikation von abweichenden Mustern vorgestellt. Methode: zunächst wird ein Rasch-homogener Fragenkern erstellt mit dem in einem zweiten Schritt Personen mit abweichenden Antworten aufgrund dieser eindimensionalen Skala empirisch identifiziert werden können. Am Beispiel des Fragebogens zur Evaluation von Psychotherapieverläufen wird das Verfahren anhand einer gemischten Stichprobe (N = 537) demonstriert. Schlussfolgerung: Das Vorgehen generiert in der klinisch-psychologischen Praxis verwertbare Hinweise auf z.T. diagnostisch relevante Abweichungen.
Stellen Erfahrungen mit Krankheiten einen spezifischen Risikofaktor für Krankheitsängste dar?
Authors: Weck Florian , Bleichhardt Gaby , Hiller Wolfgang
Published: April 2009

Zusammenfassung. Theoretischer Hintergrund: Kognitive Modelle zu Hypochondrie und Krankheitsängsten beschreiben vergangene Erfahrungen mit Krankheiten als einen Risikofaktor für deren Entstehung. Diese Sichtweise wird durch mehrere empirische Untersuchungen gestützt, die jedoch nicht die allgemeine Ängstlichkeit der Personen hinreichend berücksichtigten. Fragestellung: Da Krankheitsängste hoch mit Ängstlichkeit assoziiert sind, stellt sich die Frage, ob frühere Erfahrungen mit Krankheiten einen spezifischen Risikofaktor für die Entstehung von Krankheitsängsten darstellen oder lediglich die allgemeine Ängstlichkeit bedingen. Methode: 260 Personen der Allgemeinbevölkerung wurden mittels Fragebogen über ihre Erfahrungen mit Krankheiten befragt. Zudem wurden bei diesen Personen Krankheitsängste (IAS) und allgemeine Ängstlichkeit (STAI) erfasst. Ergebnisse: Zusammenhänge zwischen Erfahrungen mit Krankheiten und Krankheitsängsten bleiben auch nach Kontrolle der Ängstlichkeit bestehen. Bei der Vorhersage von Krankheitsängsten mittels multipler Regression kommt der Ängstlichkeit mit einer Varianzaufklärung von 18% das höchste Gewicht zu. Die Anzahl verstorbener Familienangehöriger trägt darüber hinaus zur Varianzaufklärung (4%) bei. Schlussfolgerung: Insgesamt deuten die Ergebnisse auf eine multifaktorielle Genese von Krankheitsängsten hin, Erfahrungen mit Krankheiten stellen hierbei einen spezifischen Risikofaktor dar. Eine Erweiterung des kognitiven Modells wird vorgeschlagen.
Effects of improvements in near‐infrared water vapour line intensities on short‐wave atmospheric absorption
Authors: Chagas Júlio C. S. , Newnham David A. , Smith Kevin M. , Shine Keith P.
Published: April 2009

The impact of updates of spectroscopic data on the short‐wave absorption by atmospheric water vapour is examined and compared to line parameters from the 1996 edition of HITRAN database. First, the impact of the 1999 HITRAN update to near‐infrared water vapour line intensities was examined. Second, new measurements of water vapour absorption for the 0.82‐ and 0.94‐µm bands are updated in the model. The HITRAN‐99 parameters cause a globally and annually averaged increase in short‐wave absorption of 0.26 Wm−2 with values for a particular month and latitude reaching 0.41 Wm−2. The new measurements lead to a globally and annually averaged increase of 0.64 Wm−2, reaching almost 1 Wm−2 in a particular month and latitude. These two cases increase the total short‐wave absorption by the atmosphere by between 0.4 and 1 %. They contribute to resolving the discrepancy between observed and modelled short‐wave absorption and indicate a need for the spectral data for other near‐infrared and visible bands of water vapour to be re‐examined.
Variations of midlatitude ionospheric plasma density in response to an interplanetary shock
Authors: Huang Chao‐Song , Foster J. C.
Published: April 2009

We report on a direct, prompt effect of the solar wind on the midlatitude ionosphere. On November 7, 1997, an interplanetary shock impinged on the magnetopause around 1614 UT. The solar wind dynamic pressure dropped by 70% across the shock, and the interplanetary magnetic field (IMF) changed from southward to northward. The Millstone Hill incoherent scatter radar measured a significant decrease of 25‐30% in the dayside ionospheric F region plasma density over 37° and 44° geographic latitudes within 1.5 hours and a drop of 23% in the total electron content (TEC). We propose that the decrease of the ionospheric density is associated with the decompression of the magnetosphere and/or the direct penetration of interplanetary electric field into the inner magnetosphere.
Can we consider the Arctic Oscillation independently from the Barents Oscillation?
Authors: Tremblay L.‐Bruno
Published: April 2009

An EOF analysis of a constructed time series mimicking the Northern Hemisphere SLP variability of the last 50 years shows that the Barents Oscillation (BO) appears as a means to represent the sudden eastward shift of the northern center of action associated with the Arctic Oscillation (AO) observed in the mid‐seventies. This sudden shift (non‐stationarity) appears in an EOF analysis as a step change in the relative phase between the principal components associated with the EOFs of the AO and BO. The results also show that an EOF analysis of a constant amplitude signal can produce artificial trends and/or amplitude changes in the principal component associated with a given mode (eg. AO) when such non‐stationarities are present in the signal. In this case, different modes of variability represented by EOF's cannot be considered independently from one another. In the example presented, although the principal components are completely uncorrelated from one another, perfect correlation and anti‐correlation are present in the first and second parts of the time series respectively.
Constraints on the utility of MnO2 cartridge method for the extraction of radionuclides: A case study using 234Th
Authors: Baskaran M. , Swarzenski P. W. , Biddanda B. A.
Published: April 2009

Large volume (102–103 L) seawater samples are routinely processed to investigate the partitioning of particle reactive radionuclides and Ra between solution and size‐fractionated suspended particulate matter. One of the most frequently used methods to preconcentrate these nuclides from such large volumes involves extraction onto three filter cartridges (a prefilter for particulate species and two MnO2‐coated filters for dissolved species) connected in series. This method assumes that the extraction efficiency is uniform for both MnO2‐coated cartridges, that no dissolved species are removed by the prefilter, and that any adsorbed radionuclides are not desorbed from the MnO2‐coated cartridges during filtration. In this study, we utilized 234Th‐spiked coastal seawater and deionized water to address the removal of dissolved Th onto prefilters and MnO2‐coated filter cartridges. Experimental results provide the first data that indicate (1) a small fraction of dissolved Th (<6%) can be removed by the prefilter cartridge; (2) a small fraction of dissolved Th (<5%) retained by the MnO2 surface can also be desorbed, which undermines the assumption of uniform extraction efficiency for Th; and (3) the absolute and relative extraction efficiencies can vary widely. These experiments provide insight on the variability of the extraction efficiency of MnO2‐coated filter cartridges by comparing the relative and absolute efficiencies and recommend the use of a constant efficiency on the combined activity from two filter cartridges connected in series for future studies of dissolved 234Th and other radionuclides in natural waters using sequential filtration/extraction methods.
How much climate change can be avoided by mitigation?
Authors: Washington Warren M. , Knutti Reto , Meehl Gerald A. , Teng Haiyan , Tebaldi Claudia , Lawrence David , Buja Lawrence , Strand Warren G.
Published: April 2009

Avoiding the most serious climate change impacts will require informed policy decisions. This in turn will require information regarding the reduction of greenhouse gas emissions required to stabilize climate in a state not too much warmer than today. A new low emission scenario is simulated in a global climate model to show how some of the impacts from climate change can be averted through mitigation. Compared to a non‐intervention reference scenario, emission reductions of about 70% by 2100 are required to prevent roughly half the change in temperature and precipitation that would otherwise occur. By 2100, the resulting stabilized global climate would ensure preservation of considerable Arctic sea ice and permafrost areas. Future heat waves would be 55% less intense, and sea level rise from thermal expansion would be about 57% lower than if a non‐mitigation scenario was followed.
Reservoir infill by hyperpycnal deltas over bedrock
Authors: Lai Steven Y. J. , Capart H.
Published: April 2009

We propose a simple morphodynamic theory of reservoir deltas prograding over bedrock under the influence of turbid underflows. The theory models the geomorphic actions of fluvial and hyperpycnal flows as diffusion processes, and treats bedrock‐alluvial and river‐lake transitions as moving internal boundaries. It yields self‐similar analytical solutions for the co‐evolving river and lake bed profiles, under different slope and influx conditions. These include a special case in which delta deposits are swept underwater to prograde into a subaqueous turbid pool. The theoretical predictions are in good agreement with microscale experiments, and should help interpret and anticipate longitudinal sedimentation patterns in mountain reservoirs.
Constitutive properties of clayey fault gouge from the Hanaore fault zone, southwest Japan
Authors: Noda Hiroyuki , Shimamoto Toshihiko
Published: April 2009

Velocity step tests at a range of slip rates (0.0154–155.54 μm s−1) are performed using natural fault gouge containing smectite, mica, and quartz collected from an outcrop of the Hanaore Fault, southwest Japan. Field and microscopic observations reveal that the shear deformation is localized to a few centimeters or thinner layer of black clayey fault gouge. This layer is formed by multiple stages, and determining the width of the shear zone due to a single event is difficult to determine. The experimental data on the abrupt jumps in the load point velocity are fitted by a rate‐ and state‐dependent frictional law, coupled with the spring‐slider model, the stiffness of which is treated as a fitting parameter. This treatment is shown to be essential to determine the constitutive parameters and their errors. The velocity steps are successfully fit with typically two state variables: larger b1 with shorter dc1 and smaller b2 with longer dc2. At slip rates higher than 1 μm s−1, negative b2 is required to fit the data in most of the cases. Thin gouge layers (∼200 μm) in the experiment enables us to simulate large averaged shear strain which is important to recognize the evolution of the state variable associated with negative b2 and long dc2. Observation of microscopic structure after experiments shows poor development of Y planes. This may be consistent with the mechanical behavior observed: weak occurrence of initial peak strength at yielding and displacement hardening throughout the experiments.
Intraplate deformation and microplate tectonics of the Yellowstone hot spot and surrounding western U.S. interior
Authors: Puskas C. M. , Smith R. B.
Published: April 2009

Contemporary deformation of the Yellowstone hot spot and surrounding western United States is analyzed using tectonic microplate modeling, employing constraints from GPS observations corrected for postseismic deformation of M7+ earthquakes, fault slip rates, and earthquake focal mechanisms. We focus primarily on the kinematics of the Yellowstone hot spot and the eastern Snake River Plain volcanic field (ESRP), and secondarily on Basin‐Range and Columbia Plateau provinces. Our results reveal southwest motion of the Yellowstone Plateau, excluding localized volcanic deformation, at 0.9 ± 0.1 mm/a that decreases to 0.8 ± 0.1 mm/a in the ESRP block. The southwest to west motion of the Yellowstone‐ESRP introduces shear in the northern Rocky Mountain block, which is translating east at 0.78 ± 0.08 mm/a. There is <0.5 mm/a differential motion between the ESRP and the block at its northern boundary and none at the southern boundary. The eastern Basin‐Range block moves west at 3.0 ± 0.1 to 4.6 ± 0.1 mm/a, while velocities of the western Basin‐Range microplates rotate to a northwest direction, accompanied by a transition from normal to oblique shear deformation. Columbia Plateau block velocities are notably eastward, an effect enhanced by postseismic relaxation following the M9 1700 Cascadia subduction zone paleoearthquake. This study reveals that the overall motion of the western United States is characterized by clockwise rotation, with westward extension and northwest shear in the Basin‐Range province, northeast to east contraction in the Columbia Plateau, and southwest extension of the Yellowstone–Snake River Plain block that is driven by the high gravitational potential of the Yellowstone swell.
Effects of intratidal and tidal range variability on circulation and salinity structure in the Cape Fear River Estuary, North Carolina
Authors: Becker May Ling , Luettich Richard A. , Seim Harvey
Published: April 2009

Tidal influences on circulation and the salinity structure are investigated in the largely unstudied Cape Fear River Estuary (CFRE), North Carolina, a partially mixed estuary along the southeast coast of the United States. During two different tidal conditions (high versus low tidal range) and when river flow was low, salinity and velocity data were collected over a semidiurnal tidal cycle in a 2.8 km long transect along the estuary axis. Water level data were recorded nearby. Mechanisms that influence salt transport characteristics are diagnosed from an analysis of the field data. Specifically, we investigated the relationship between tidal range and salinity through comparison of along‐channel circulation characteristics, computed salt fluxes, and coefficients of vertical eddy diffusivity (Kz) based on a parameterization and on salt budget analysis. Findings indicate up‐estuary tidally driven salt fluxes resulting from oscillatory salt transport are dominant near the pycnocline, while mean advective transport dominates near the bottom during both tidal range periods. Earlier research related to salt transport in estuaries with significant gravitational circulation suggests that up‐estuary salt transport increases during low tidal ranges as a result of increased gravitational circulation. In the CFRE, in contrast, net (tidally averaged) near‐bottom along‐channel velocities are greater during higher tidal range conditions than during lower tidal range conditions. Findings indicate stronger tidal forcing and associated mixing contribute to greater near‐bottom salinity gradients and, consequently, increased baroclinic circulation. Lower near‐bottom salinities during the higher tidal range period are a result of a combination of increased vertical turbulent salt fluxes near the pycnocline and increased bottom‐generated mixing.
Land or ocean?: Assessing the driving forces of submarine groundwater discharge at a coastal site in the Gulf of Mexico
Authors: Santos Isaac R. , Burnett William C. , Chanton Jeffrey , Dimova Natasha , Peterson Richard N.
Published: April 2009

Submarine groundwater discharge (SGD) is an important pathway of trace element and nutrient cycling in the coastal ocean. Since terrestrial and marine SGD driving forces are usually superimposed, it is difficult to separate their relative contributions. This work uses continuous, long‐term (∼2 years) records of seawater 222Rn to estimate total SGD rates and hydrological observations to examine the driving forces of SGD at a coastal site on the Gulf of Mexico. While seasonal cycles cannot be clearly identified, short‐term fluctuations were ubiquitous. Radon‐derived SGD was strongly associated with the neap spring tidal cycle, at least during a period of extreme drought when minimum external disturbances were present. We applied multiple independent approaches to separate the relative contribution of fresh and saline SGD. A salinity mixing model indicated that the contribution of fresh SGD ranged between 3 and 12%. The rate of freshening of water within a seepage meter required vertical freshwater advection of ∼0.9 cm d−1 at low tide, which is <10% of the total SGD estimated from 222Rn (∼11 cm d−1). Darcy's law calculations and water table decline rate also suggested a fresh SGD contribution <5%. The temporal trends in total SGD and the reasonable agreement of our multiple approaches indicate that transient marine forces, likely tidal pumping, dominate benthic advective exchange in these permeable sediments. Compared to regional river inputs, our conservatively extrapolated saline SGD is on the same order of magnitude, but fresh groundwater only represents a small fraction. Future investigations should refine techniques for scaling up local observations.
Seasonality of speciated aerosol transport over the Great Lakes region
Authors: Spak Scott N. , Holloway Tracey
Published: April 2009

The Community Multiscale Air Quality model (CMAQ) is used to simulate aerosol mass and composition in the Great Lakes region of North America in an annual study for 2002. Model predictions are evaluated against daily and weekly average speciated fine particle (PM2.5) and bulk (PM2.5 and PM10) mass concentration measurements taken throughout the region by the Interagency Monitoring of Protected Visual Environments (IMPROVE), Speciation Trends Network (STN), and Clean Air Status and Trends Network (CASTNet) monitoring networks, and number concentration is evaluated using hourly observations at a rural site. Through detailed evaluation of model‐measurement agreement over urban and remote areas, major features of aerosol seasonality are examined. Whereas nitrate (winter maximum) and sulfate (summer maximum) seasonal patterns are driven by climatic influence on aerosol thermodynamics, seasonality of ammonium and organic mass (OM) is driven by emissions. Production of anthropogenic secondary organic aerosol (SOA) and summertime ozone formation both reach regional maxima over the southern Great Lakes, where they are also most strongly temporally correlated. Although primary OM is more prevalent, insufficient SOA formation leads to summertime OM underprediction of more than 50%. By comparing temporal patterns in aerosol species between model and observations, we find that elemental carbon, OM, and PM2.5 are overly correlated in CMAQ, suggesting that the model misses chemical, transport, or emissions processes differentiating these constituents. In contrast, sulfate and PM2.5 are not sufficiently correlated in CMAQ, although CMAQ simulates sulfate with a high level of skill. Performance relative to ad hoc regional modeling goals and previous studies is average to excellent for most species throughout the year, and seasonal patterns are captured.
Transport pathways of carbon monoxide in the Asian summer monsoon diagnosed from Model of Ozone and Related Tracers (MOZART)
Authors: Park Mijeong , Randel William J. , Emmons Louisa K. , Livesey Nathaniel J.
Published: April 2009

Satellite observations of tropospheric chemical constituents (such as carbon monoxide, CO) reveal a persistent maximum in the upper troposphere–lower stratosphere (UTLS) associated with the Asian summer monsoon anticyclone. Diagnostic studies suggest that the strong anticyclonic circulation acts to confine air masses, but the sources of pollution and transport pathways to altitudes near the tropopause are the subject of debate. Here we use the Model for Ozone and Related Tracers 4 (MOZART‐4) global chemistry transport model, driven by analyzed meteorological fields, to study the source and transport of CO in the Asian monsoon circulation. A MOZART‐4 simulation for one summer is performed, and results are compared with satellite observations of CO from the Aura Microwave Limb Sounder and the Atmospheric Chemistry Experiment Fourier Transform Spectrometer. Overall, good agreement is found between the modeled and observed CO in the UTLS, promoting confidence in the model simulation. The model results are then analyzed to understand the sources and transport pathways of CO in the Asian monsoon region, and within the anticyclone in particular. The results show that CO is transported upward by monsoon deep convection, with the main surface sources from India and Southeast Asia. The uppermost altitude of the convective transport is ∼12 km, near the level of main deep convective outflow, and much of the CO is then advected in the upper troposphere northeastward across the Pacific Ocean and southwestward with the cross‐equatorial Hadley flow. However, some of the CO is also advected vertically to altitudes near the tropopause (∼16 km) by the large‐scale upward circulation on the eastern side of the anticyclone, and this air then becomes trapped within the anticyclone (to the west of the convection, extending to the Middle East). Within the anticyclone, the modeled CO shows a relative maximum near 15 km, in good agreement with observations.
Influence of cloud condensation and giant cloud condensation nuclei on the development of precipitating trade wind cumuli in a large eddy simulation
Authors: Cheng William Y. Y. , Carrió Gustavo G. , Cotton William R. , Saleeby Stephen M.
Published: April 2009

To investigate the effects of both cloud condensational nuclei (CCN) and giant CCN (GCCN), the Regional Atmospheric Modeling System was used to investigate the effects of various CCN and GCCN concentrations on the development of precipitating trade wind cumuli in a large eddy simulation (LES) framework. The sounding to initialize the LES was taken from the Rain in Cumulus over the Ocean Experiment archive for 11 January 2005. Several sensitivity experiments were performed in which two levels of CCN (GCCN) concentrations were used: 100 (0.01) and 1000 (0.1) cm−3 corresponding to low and high values, respectively. Both CCN and GCCN can affect the precipitation processes. With low GCCN concentration, raising the CCN concentration from low to high reduced the precipitation rate as well as the accumulated precipitation due to the presence of a large number of small cloud droplets that are inefficient in forming drizzle. However, GCCN can have a greater response in increasing the precipitation rate and accumulation when the cloud system has a high CCN concentration. The total cloud coverage (TCC) was reduced for the higher CCN concentration experiments because of the susceptibility of evaporation of cloud droplets in the upper parts of the cloud as a result of entrainment. On the other hand, the TCC was increased for the higher GCCN concentration experiments. For this trade wind cumuli case, the time‐ and domain‐averaged albedo changed very slightly with increased [CCN] and/or [GCCN] because of a compensating increase/decrease among the optical depth, liquid water path, cloud coverage, and cloud droplet concentration.
Transport of north China air pollution by midlatitude cyclones: Case study of aircraft measurements in summer 2007
Authors: Ding Aijun , Wang Tao , Xue Likun , Gao Jian , Stohl Andreas , Lei Hengchi , Jin Dezhen , Ren Yu , Wang Xuezhong , Wei Xiaolin , Qi Yanbin , Liu Jian , Zhang Xiaoqing
Published: April 2009

Warm conveyor belts (WCBs) and frontal activity play important roles in the long‐range transport of air pollutants by lifting them from the planetary boundary layer (PBL) into the free troposphere (FT) in midlatitudes. In summer 2007, an aircraft study was carried out in northeast (NE) China in order to understand the role of midlatitude cyclones in air pollution transport in north and east China in warm seasons. During a flight on 27 June, high concentrations of ozone and related trace gases were observed, with maximum concentrations (O3 ∼ 140 ppbv, SO2 ∼ 14.6 ppbv, CO ∼ 1185 ppbv) recorded at an altitude of 2.6 km. In this paper we present a detailed analysis of this flight. The mesoscale meteorological model Weather Research and Forecasting (WRF) and a Lagrangian dispersion model called FLEXPART were used to aid the diagnostic analysis of the atmospheric dynamic structure and the understanding of the transport characteristics of regional and local air pollution. The flight took place in a region adjacent to a warm front associated with a weak cyclone in north China. The aircraft sampled both the WCB and warm air frontal zone of the cyclone. The simulations show that the observed high air pollution in the FT mostly originated from the North China Plain, especially the megacities Beijing and Tianjin. Their plumes were vented by a stagnant front, probably through, in part, topographic lifting by the mountains in the north, and then were quickly transported in the FT to the study region. Trajectory analysis and satellite data suggest that the observed air masses were further lifted by the WCB into the middle and upper troposphere and were exported from Asia toward North America and the Arctic.
Comment on “Plasma chemistry of sprite streamers” by D. D. Sentman, H. C. Stenbaek‐Nielsen, M. G. McHarg, and J. S. Morrill
Authors: Kamaratos Efstathios
Published: April 2009

This work raises questions about reaction mechanisms and their ramifications in relation to the model adopted by Sentman et al. (2008). The model adopted by Sentman et al. (2008) for the description of a sprite streamer promoted the {N2(a′ 1Σu−) + N2 → N2(B 3Πg) + N2} chemical reaction as the key chemical reaction, in the afterglow stage in their model, for forming N2(B 3Πg) species, which are responsible for N2 first positive band system emissions. However, it is shown in this comment that Sentman et al. (2008) used an implicitly assumed value of the {N2(a′ 1Σu−) + N2} quenching reaction rate constant for N2(B 3Πg) formation that is not supported by the conclusions in existing experimental works. It is also shown that there are additional competing chemical reactions forming N2(B 3Πg) which should be taken into account, some of which were not used in the model adopted by Sentman et al. (2008).
Daily atmospheric circulation events and extreme precipitation risk in northeast Spain: Role of the North Atlantic Oscillation, the Western Mediterranean Oscillation, and the Mediterranean Oscillation
Authors: Vicente‐Serrano Sergio M. , Beguería Santiago , López‐Moreno Juan I. , El Kenawy Ahmed M. , Angulo‐Martínez Marta
Published: April 2009

We used a novel method that combined probabilistic analysis and spatial modeling assisted by GIS to analyze the risk of extreme precipitation in northeast Spain related to three atmospheric circulation configurations: the North Atlantic Oscillation (NAO), the Mediterranean Oscillation, and the Western Mediterranean Oscillation (WeMO). The analysis was performed at an event‐based scale using data obtained from daily atmospheric circulation indices. The maximum intensity and total precipitation magnitude recorded during positive and negative circulation events were obtained from the daily records of 174 observatories between 1950 and 2006. The series of both maximum intensity and magnitude for positive and negative phases of the three atmospheric circulation indices follow a generalized Pareto (GP) distribution. A regression‐based interpolation procedure was used to generate distributed maps of GP parameters, enabling us to determine the probability of the magnitude and maximum intensity of precipitation and the quantile precipitation for any return period associated with the positive and negative phases of the three atmospheric circulation patterns. A high spatial variability in precipitation risk was found, depending on the positive/negative phases of the three atmospheric circulation patterns. Different phases of the circulation indices show contrasting effects on the two analyzed parameters. Thus the most extreme daily precipitation during winter months is expected for negative WeMO events, representing a markedly different result from those obtained for other events. In contrast, negative NAO events record the most extreme precipitation magnitude risk per event, although this is mainly restricted to mountainous areas.
Premonsoon estimates of convective available potential energy over the oceanic region surrounding the Indian subcontinent
Authors: Alappattu Denny P. , Kunhikrishnan P. K.
Published: April 2009

Convective available potential energy (CAPE) and convective inhibition energy (CIN) are important parameters in determining the stability of the atmosphere for moist convection. This paper presents the estimates of CAPE and CIN during the premonsoon season over the oceanic region surrounding the Indian subcontinent. The high‐resolution radiosonde data used in this study were collected as a part of the Integrated Campaign for Aerosols gases and Radiation Budget (ICARB; March–May 2006), which covered the Bay of Bengal, Arabian Sea, and parts of North Indian Ocean. We discuss the spatiotemporal variability of CAPE and CIN during the premonsoon period and investigate the role of boundary layer, as well as free tropospheric parameters in controlling the CAPE and CIN values. During the convective event of 9 April the sensors on board the ship recorded 4 mm of rain and an overall reduction of CAPE by 620 J kg−1was seen. This corroborates with the concept that CAPE generated by the nonconvective processes is consumed by the convection for its intensification. However, the observed reduction in CAPE after this convective event is much less compared to the monsoon season reported elsewhere. CIN was found to be anticorrelated with the free convection depth (FCD), which is the distance through which the parcel ascends by its own buoyancy. Thus the variability in CAPE and CIN is found to be interlinked through the FCD. Apart from this, contribution to total CAPE from various levels are also estimated, which shows that the CAPE in the middle levels contributes most toward the total CAPE. Our investigations show that although the CAPE and CIN are related to the tropospheric parameters like temperature lapse rate, the variability in CAPE and CIN is essentially determined by the moisture in the atmospheric boundary layer. As the equivalent potential temperature (θE) in the ABL increases, CAPE increases, favoring the development of convection.
Simulating and understanding sand wave variation: A case study of the Golden Gate sand waves
Authors: Sterlini F. , Hulscher S. J. M. H. , Hanes D. M.
Published: April 2009

In this paper we present a detailed comparison between measured features of the Golden Gate sand wave field and the results of a nonlinear sand wave model. Because the Golden Gate sand waves exhibit large variation in their characteristics and in their environmental physics, this area gives us the opportunity to study sand wave variation between locations, within one well‐measured, large area. The nonlinear model used in this paper is presently the only tool that provides information on the nonlinear evolution of large‐amplitude sand waves. The model is used to increase our understanding of the coupling between the variability in environmental conditions and the sand wave characteristics. Results show that the model is able to describe the variation in the Golden Gate sand waves well when both the local oscillating tidal current and the residual current are taken into account. Current and water depth seem to be the most important factors influencing sand wave characteristics. The simulation results give further confidence in the underlying model hypothesis and assumptions.
Design and deployment of a portable membrane equilibrator for sampling aqueous dissolved gases
Authors: Loose B. , Stute M. , Alexander P. , Smethie W. M.
Published: April 2009

We present designs for a portable trace gas sampler, based on membrane technology, to obtain a gas sample from water in the field. A continuous flow of water is equilibrated with a finite volume of gas until the gas pressure matches the total dissolved gas pressure of the water stream. Samples collected in this manner can be analyzed to determine original water concentrations for potentially any dissolved gas. The sampler requires neither compressed carrier gas nor a vacuum pump to extract the dissolved gas sample; its power consumption is minimal and it fits within a 30 L plastic case. During the development stages, both major atmospheric gases (N2, O2, and Ar) and trace gases (CO2, SF6, and SF5CF3) were measured to confirm the equilibrium condition and to quantify the response time. Equilibration studies were conducted in the laboratory and at the site of a borehole CO2 injection experiment on the Lamont campus of Columbia University. The time required to achieve solubility equilibrium depends on the dissolved gas content and the water flow rate; we determined an e‐folding response time of 9–12 min, under air‐saturated conditions and with a flow rate of 2 L/min. Typically, equilibrium is achieved within 30–45 min. We compare the system function and analytical results to conventional sampling methods during the recovery phase of a push‐pull experiment and find a generally good agreement within 10% of conventional analyses for each of the gases.
Spatial patterns of rainfall and shallow landslide susceptibility
Authors: Minder Justin R. , Roe Gerard H. , Montgomery David R.
Published: April 2009

We quantify the effect of spatial patterns in climatological rainfall on shallow landslide susceptibility by forcing a physically based model of slope stability (SHALSTAB) with the rainfall pattern produced by a high‐resolution atmospheric model (MM5) over the western Olympic Mountains of Washington State. Our results suggest that for two small basins in the Olympics, 10 km–scale variations in rainfall have a nontrivial effect on landslide susceptibility. Assuming uniform rainfall equal to the average rainfall over the basins results in a moderate underestimate of landslide susceptibility. Using climatological data from a lowland station to characterize the rainfall over the basins results in a substantial underestimate of susceptibility. The effect of spatial variability in rainfall on variations in stability is comparable to the effect of moderate‐to‐large variability in soil parameters (such as ±30% variations in soil thickness). At a practical level, these results imply that accounting for persistent patterns of rainfall may aid in discerning regions within the same watershed where similar land use practices will lead to differing landslide risk.
Characterization of reservoir simulation models using a polynomial chaos‐based ensemble Kalman filter
Authors: Saad George , Ghanem Roger
Published: April 2009

Model‐based predictions of flow in porous media are critically dependent on assumptions and hypotheses that are not always based on first principles and that cannot necessarily be justified on the basis of known prevalent physics. Constitutive models, for instance, fall under this category. While these predictive tools are usually calibrated using observational data, the scatter in the resulting parameters has typically been ignored. In this paper, this scatter is used to construct stochastic process models of the parameters which are then used as the cornerstone in a novel model validation methodology useful for ascertaining the confidence in model‐based predictions. The uncertainties are first quantified by representing the unknown model parameters via their polynomial chaos decompositions. These are descriptions of stochastic processes in terms of their coordinates with respect to an orthogonal basis. This is followed by a filtering step to update these representations with measurements as they become available. In order to account for the non‐Gaussian nature of model parameters and model errors, an adaptation of the ensemble Kalman filter is developed. Instead of propagating an ensemble of model states forward in time as is suggested within the framework of the ensemble Kalman filter, the proposed approach allows the propagation of a stochastic representation of unknown variables using their respective polynomial chaos decompositions. The model is propagated forward in time by solving the system of partial differential equations using a stochastic projection method. Whenever measurements are available, the proposed data assimilation technique is used to update the stochastic parameters of the numerical model. The proposed method is applied to a black oil reservoir simulation model where measurements are used to stochastically characterize the flow medium and to verify the model validity with specified confidence bounds. The updated model can then be employed to forecast future flow behavior.