bluuebunny/crossref_metadata_2025 huggingface dataset:
The pelagic life of the pectinid Pecten maximus—a review
Authors: Le Pennec M , Paugam A , Le Pennec G
Published: July 2003

Although marine bivalves go through a planktonic larval phase, knowledge of this phase is often poor because of the difficulty in identifying and monitoring the activity of these tiny organisms within the water mass. Some bivalves have been studied more than others, often because of their economic value. These species can serve as a model for improving our understanding of the circumstances of planktonic larval development, in particular by assessing its impact on recruitment. This review is aimed at summarizing the knowledge on the pelagic life of Pecten maximus acquired by research in France over the last 25 years. The comparison of these results with those obtained elsewhere for pectinid species, indicates certain characteristics that appear to be fairly common to all coastal infralittoral pectinids. Regardless of species, pelagic life of pectinids starts with the release of gametes, followed by fertilization and embryonic and larval stages until metamorphosis and recruitment to the benthic community. After consideration of the main characteristics of the pelagic stages and their sensitivity to certain environmental factors, a graphic synthesis is provided displaying their migratory behaviour and the possible consequences for recruitment.
Reconciling theoretical versus empirical target strengths of krill: effects of phase variability on the distorted-wave Born approximation
Authors: Demer David A. , Conti Stephane G.
Published: July 2003

A model was recently proposed to predict the target strengths (TS) of Antarctic krill, Euphausia superba, versus incidence angle (θ) (Deep Sea Res. II 45(7) (1998) 1273). Based on the distorted-wave Born approximation (DWBA), the model depends on the coherent summation of scattering from elements of a discretized-bent cylinder. It was empirically validated at 120 kHz near-broadside incidence (θ≈90°), but large discrepancies were observed at other angles away from the main lobe. As the side-lobe measurements were both higher than the model predictions and above the noise floor, the authors noted that the differences were not entirely due to noise. In this study, the accuracy of the DWBA model is further explored. Results indicate that phase variability in the scatter from elements of a discretized-bent cylinder (krill model) causes a dramatic flattening in the side-lobe regions of TS(θ), while negligibly affecting the main scattering lobe. These results are consistent with the krill TS measurements reported by McGehee et al. Thus, by accounting for phase variability in the solution of the DWBA model, a more accurate and thus practical tool is developed for predicting krill TS.
On estimating the age composition of the commercial catch of Northeast Arctic cod from a sample of clusters
Authors: Sondre Aanes , Pennington Michael
Published: July 2003

Assessment of Northeast Arctic cod is based on estimates of the commercial catch in numbers at age. The age structure of the catch is estimated by sampling fish from commercial fishing trips. Although it is commonly assumed that a sample of individuals is a random sample from the population, fish sampled from the same trip (i.e. from a “cluster” of fish) tend to be more similar in age than those in the total catch. For Northeast Arctic cod, the intracluster correlation for age is positive, and therefore the effective sample size is much smaller than the number of fish aged. Given the number of fish aged, the precision of the estimated age distribution is rather low, and the number of fish aged from each trip could be reduced from approximately 85 to 20 without a significant loss in precision.
Ichthyoplankton distribution and plankton production related to the shelf break front at the Avilés Canyon
Authors: González-Quirós R , Cabal J , Álvarez-Marqués F , Isla A
Published: July 2003

The overall objective of this study was to search for spatial differences in primary production and its transference towards larval fish related with the distribution of water masses at shelf break of the Avilés Canyon. High primary production and ichthyoplankton abundance were associated with a shelf break front at the Avilés Canyon. Egg distributions of Scomber scombrus, Sardina pilchardus and Trachurus trachurus, coupled with topography, the associated physical structure and phytoplankton productivity, suggested adaptive spawning strategies. The distribution of copepod stages, which are considered the trophic link between primary producers and fish larvae, was not related with the position of the front. Moreover, the egg production of two abundant species (Calanus helgolandicus and Acartia clausi) was not significantly related with phytoplankton abundance and productivity.
Age at maturation predicted from routine scale measurements in Norwegian spring-spawning herring (Clupea harengus) using discriminant and neural network analyses
Authors: Engelhard Georg H , Dieckmann Ulf , Godø Olav Rune
Published: July 2003

We evaluate two methods allowing the prediction of age at maturation from the widths of the annual growth layers in scales (or otoliths) in a case study on Norwegian spring-spawning herring. For this stock, scale measurements have been made routinely for many decades. We compare the performance in classifying age at maturation (at 3, 4,…,9 years) between conventional discriminant analysis (DA) and the new methodology of artificial neural networks (NN) trained by back-propagation against a ‘control’ of historical estimates of age at maturation obtained by visual examination of scales. Both methods show encouraging, and about equally high, classification success. The marginal differences in performance are in favour of DA, if the proportion of correctly classified cases is used as criterion (DA 68.0%, NN 66.6%), but in favour of NN if other criteria are used, including prediction error (error >1 year: DA 5.2%, NN 2.9%), and the average degree of under- or overestimation (underestimation 1.1% of mean with DA; overestimation 0.2% of mean with NN). Evidence is provided that both methods approach the a priori limits to maximal classification success, limits set by overlapping combinations of predictor variables between maturation groups. The methods allow studies on age at maturation in this stock over a very long timespan, including periods well before, during, and after its collapse to commercial extinction. Similar techniques might well be applicable to any other fish stock with long-term data on scale or otolith growth layers.
Reconstruction of environmental histories to investigate patterns of larval radiated shanny (Ulvaria subbifurcata) growth and selective survival in a large bay of Newfoundland
Authors: Baumann Hannes , Pepin Pierre , Davidson Fraser J.M , Mowbray Fran , Schnack Dietrich , Dower John F
Published: July 2003

We used otolith microstructure analysis to reconstruct the growth histories of larval radiated shanny (Ulvaria subbifurcata) collected over a 2-week period in Trinity Bay, Newfoundland. A dynamic 3-dimensional, eddy-resolving circulation model of the region provided larval drift patterns, which were combined with measurements of temperature and zooplankton abundance to assess the environmental history of the larvae. The abundance of juvenile and adult capelin (Mallotus villosus), the dominant planktivorous fish in this area, was monitored using five hydroacoustic surveys. The goal was to determine whether environmental histories are helpful in explaining spatial and temporal differences in larval shanny growth, measured as cumulative distribution functions (CDF) of growth rates. We found evidence for a selective loss of slower growing individuals and recognized considerable spatial differences in the CDF of larval growth rates. Consistent patterns in capelin abundance suggested that faster growing survivors, sampled at the end of the 2-week period, developed in areas of low predator densities. A dome-shaped relationship between temperature and larval growth was observed, explaining a significant but small amount of the overall variability (14%). Effects of experienced prey concentrations on larval growth rates could not be demonstrated.
Development of wild Atlantic salmon stocks in the rivers of the northern Baltic Sea in response to management measures
Authors: Romakkaniemi A , Perä I , Karlsson L , Jutila E , Carlsson U , Pakarinen T
Published: July 2003

Since 1980, the abundance of wild Atlantic salmon has been monitored by means of catch records, adult counts, electrofishing and smolt trapping in six rivers flowing into the northern Baltic Sea. River abundance (spawners, parr and smolts) was compared with implemented large-scale and river-specific management measures and with natural factors potentially affecting abundance. Since the 1980s, the wild stocks have recovered in a synchronous cyclical pattern. The recovery occurred mainly in two jumps, first a sudden increase dating back to around 1990 and a second sharp rise in the late 1990s. River abundance of young salmon commonly rose about 10-fold and approached the previously estimated production capacity in some of the rivers. This positive development may be explained by a decline in fishing pressure together with covarying natural factors influencing survival and growth. The offshore fishery started to decline at the time of the first increase, while the reduction in the total allowable catches together with seasonal restrictions on the coastal fishery strengthened the second increase. Improved natural conditions seem to have increased both survival and escapement during the first rise. Spawners producing the second rise were the offspring of the spawners of the first rise. The outbreak of the M74 mortality syndrome among alevins reduced the abundance of several year-classes that hatched during the first half of the 1990s. In most rivers, the fraction of older and female fish in the spawning run has increased over the period, thereby increasing the reproductive capacity of the populations. No distinct effects of variations in river-specific management regimes were observed. Instead, the results emphasize the role of fisheries management in the open sea as well as in coastal waters, and also of non-human factors in controlling overall abundance of wild salmon in northern Baltic rivers.
Ocean thermal conditions in the post-smolt nursery of North American Atlantic salmon
Authors: Friedland Kevin D , Reddin David G , Castonguay Martin
Published: July 2003

The effect of climate on the post-smolt survival of North American Atlantic salmon is obscure owing to the difficulty in interpreting the only relationships thus far observed between the abundance of these stocks and climate, which focuses on winter conditions. Placing significance on winter post-smolt survival is contrary to conventional thinking that the spring period is more important, because that is when the post-smolts migrate to sea and transition to ocean life takes place. The pre-fishery abundance for North American stocks was compared to thermal conditions in potential post-smolt nursery areas during the period 1982–1999. Pre-fishery abundance was modeled as a reconstruction of one-sea-winter (1SW) and two-sea-winter (2SW) age salmon populations. Cohort abundance was compared to mean temperature and thermal habitat (sea surface area within a given temperature range) in five index areas. Stock size was negatively correlated with mean sea surface temperature during June. Correlations were comparatively stronger between stock abundance and thermal habitat, further asserting that June conditions – the first month at sea for most stocks in the region – may be pivotal to survival. These correlations suggest that post-smolt survival is negatively affected by the early arrival of warm ocean conditions in the nursery area. Hypotheses related to post-smolt migration, predation, and the availability of suitable prey are discussed.
Fine-scale linkages between the diving behaviour of Antarctic fur seals and oceanographic features in the southern Indian Ocean
Authors: Lea Mary-Anne , Dubroca Laurent
Published: July 2003

Diving activity, foraging locations and pup provisioning behaviour of 10 female Antarctic fur seals (Arctocephalus gazella) were examined with respect to a range of oceanographic parameters (sea surface temperature, chlorophyll distribution and bathymetry) at the Kerguelen Archipelago in the southern Indian Ocean in February 2000. A multivariate analysis of the environmental parameters at each of the nightly foraging locations indicated the existence of two ecoregions within the foraging range of the seals. Five seals actively foraged in oceanic waters (1870 m) with relatively warm surface water (5.4°C) to the north and east of the colony (ecoregion 1), while four others travelled to the southeast (ecoregion 2) to waters typical of the surface expression of the Polar Front (3.7°C) located over the continental shelf break (597 m). Only one seal foraged in both regions. Diving behaviour, parameterised on a nightly basis using seven variables, clearly differed between regions, with the diving activity in the warmer ecoregion 1 being characterised by deep dives (55 m), and relatively little time spent diving (47%). Conversely, dives within ecoregion 2 were, on average, to shallower depths (34.5 m), and proportionately more time was spent diving (54%). Despite differences in environmental conditions encountered and associated differences in diving activity, the foraging success of mothers, in terms of daily pup mass gain per foraging cycle, was similar in both ecoregions. The study highlights the use of multivariate analysis in categorising the foraging zones and behaviour of Antarctic fur seals.
Are gap junction membrane plaques implicated in intercellular vesicle transfer?
Authors: Gruijters W.T.M.
Published: July 2003

Gap junction channels are concentrated in specialised plaques of plasma membrane where cells are in close apposition. In this communication evidence is provided showing that these specialised regions of membrane also provide a site for vesicular transfer between cells. Vesicle distribution in eye lenses was found to generally reflect the reported distribution of gap junction membrane plaques. In certain areas of the lens gap junction membrane plaques and vesicles could be seen to form combined, complex structures. Ultrastructure of the vesicle and gap junction membrane plaque complexes was consistent with the vesicles moving through membrane plaques from one lens fibre cell to the next. To investigate whether transport of substances was consistent with intercellular vesicle transfer, transport of various markers was investigated. Time course experiments showing the rate of uptake of various markers into the lens did not show dramatic differences for molecules smaller or larger then gap junction pores formed by connexons. While considered as a primary intercellular transport mechanism in the lens, connexon pores were not the sole agent mediating the observed transport. Other reported mechanisms of intercellular transport in the lens can only account for the movement of relatively small molecules. Vesicular transport may therefore be a major form of transport into the outer lens layers for larger molecules. Implicit in these observations is a new hypothesis for intercellular vesicle movement via gap junction membrane plaques. Intercellular vesicle movement could possibly provide a path for large molecules associated with intact vesicles to be transported into the eye lens tissue.
The Cult of the Silkworm Mother as a Core of Local Community Religion in a North China Village: Field Study in Zhiwuying, Boading, Hebei
Authors: Lizhu Fan
Published: July 2003

This article deals with an example of local community religion in north China, the activities of a woman spirit-medium in a small village in Hebei province. This woman is believed to represent an ancient goddess, the Silkworm Mother (Cangu nainai), to whom people turn for healing illnesses not cured by Western or Chinese medicine. This study shows that local popular religion is very much alive in contemporary China.
A Nameless but Active Religion: An Anthropologist's View of Local Religion in Hong Kong and Macau
Authors: Liu Tik-sang
Published: July 2003

Tik-sang Liu examines local religious practices in Hong Kong and Macau. He states that these constitute the foundation of local social organizations; they are the means with which local society is organized, local people are mobilized, communal activities are co-ordinated and people are prepared for their various stages in life.
Religion and the State in Post-war Taiwan
Authors: Katz Paul R.
Published: July 2003

This article explores the development of local religious traditions in post-war Taiwan, particularly since the ending of martial law in 1987. It focuses on the factors underlying the ongoing popularity of temple cults to local deities such as Mazu (originally the goddess of the sea, now worshipped as an all-powerful protective deity) and the Royal Lords (Wangye; plague deities now invoked to counter all manner of calamities). Special attention is devoted to the complex relationship between local community-based religious traditions and the state, including the loosening of restrictions on festivals, the use of temples as sites for political rallies during local elections, and the recent controversy over attempts to stage direct pilgrimages to mainland China. Other issues include debates over the “indigenization” of religious traditions in Taiwan and the growth of academic organizations devoted to the study of Taiwanese religion.
Whither China? Intellectual Politics in Contemporary China. Edited by Xudong Zhang. [Durham: Duke University Press, 2001. ix+391 pp. $23.95. ISBN 0-8223-2648-5.]
Authors: Kraus Richard
Published: July 2003

This important collection of theoretically oriented essays on contemporary Chinese culture and politics is an updated and expanded version of a special issue of Social Text (Summer 1998). The selection is multidisciplinary (including history, political science, anthropology) but with an expansive conception of comparative literature at its core. It is more intellectually focused than many China anthologies, no doubt reflecting the strong guiding hand of editor Xudong Zhang, whose 75-page introduction sets an ambitious agenda.
China's Long March Toward Rule of Law. By Randall Peerenboom. [Cambridge: Cambridge University Press, 2002. xviii+673 pp. £80.00. ISBN 0-521-81649-1.]
Authors: Potter Pitman B.
Published: July 2003

Randall Peerenboom has become one of the most prolific specialists writing in English about the legal system of post-Mao China. In his latest book, Peerenboom provides a summary overview of the development of the post-Mao legal system, drawing on a number of his previously published works on issues such as lawyers, globalization, human rights, and legal theory.
China Human Development Report 2002: Making Green Development a Choice. Produced by Stockholm Environment Institute in collaboration with UNDP. [Hong Kong: Oxford University Press, 2002. 152 pp. ISBN 0-19-593603-5.]
Authors: Monks Fran
Published: July 2003

The 2002 China Human Development Report explores the interaction between Chinese society and the environment, and the responses of government and the people to the challenge of finding a more sustainable development path. It states that “China is at a juncture of increased scarcity of natural resources with declining environmental quality and intensified social pressures.”
Why we need independent Centres for Advanced Study
Authors: CONNOR W. ROBERT
Published: July 2003

Institutes for Advanced Study provide havens for advancing scholarship, particularly in the humanities and social sciences, and have increased in number in recent years. The article explores the reasons for this development.
Judge and lawgiver in Anglo-American history
Authors: VAN CAENEGEM R. C.
Published: July 2003

Politicians are not expected to interfere with the judiciary. Parliament passes laws and the courts interpret and apply them. On the Continent, judicial freedom is restricted by codification, which was avoided in England where greater judicial flexibility survived. In the United States the Restatement of the Law was a move in the direction of codification. Also in that country, judicial review of the constitutionality of the laws gave the judges the power to declare statutes passed by the representatives of the people unconstitutional. No such power exists in England, but the courts have other means of reducing the impact of Acts of Parliament, such as the exclusionary rule and the convention that the lawgiver does not intend to change the common law, which is judge-made case law, governed by the doctrine of precedent. Those traditional elements of the English common law were recently eroded by modernizing trends: the rule of exclusion was given up in favour of the search for the intention of the lawgiver, and the force of stare decisis was reduced. The recent incorporation of the European Convention on Human Rights into British law has introduced a form of judicial review of the laws into the British system.
Globalization and global governance: from societal to political denationalization
Authors: ZÜRN MICHAEL
Published: July 2003

The declining significance of national borders constitutes a challenge to the capacity of the nation-state to reach unilaterally its governance targets. Effective governance depends upon the spatial congruence of political regulations with socially integrated areas and the absence of significant externalities. As societal interconnectedness across borders increases with globalization, national governments are increasingly confronted with four specific challenges: efficiency pressures, externality and competitiveness problems, and representational deficits. The political responses to these challenges vary significantly. Although globalization is thus neither identical with, nor does it necessarily lead to, the rise of international institutions and governance beyond the nation-state, this article will show to what extent societal denationalization is accompanied by the rise of international institutions and how the myriad of international institutions existing today interact to produce global governance. Globalization also questions a cornerstone of any modern understanding of politics, which considers nation-states as the basis of all politics. As governance beyond the nation-state increases in significance, the separation of political issues into nationally defined territorial units must be conceptualized as a variable rather than a conceptual premise.
Human races and evolutionary medicine
Authors: SWYNGHEDAUW BERNARD
Published: July 2003

Data from the Human Genome Programme has clearly established that the human race is unique. Attempts to identify separately Black, Caucasian and Asian, did not establish a biological basis, which is an interesting socioeconomic point. Evolutionary medicine takes the view that many contemporary diseases are likely to result from the incompatibility between a contemporary lifestyle and dietary habits and the conditions under which the evolutionary pressure had modified our genetic inheritance. The search for gene variants or mutations, which could be associated with arterial hypertension, atherosclerosis and/or cancer, should be directed towards such metabolic genes.
Lexical Ambiguity Resolution Across Languages: A Theoretical and Empirical Review
Authors: Altarriba Jeanette , Gianico Jennifer L.
Published: July 2003

Abstract. Words that involve completely different meanings across languages but possess significant overlap in form are referred to as homographic noncognates or interlexical homographs (e.g., red is a color word in English but means “net” in Spanish). An important question in the investigation of the processing of these words is whether or not both meaning and form are integral to their representation leading to language-specific processing of these items. In contrast, some theories have been put forth indicating that the processing of these words is nonselective with regards to language. Simply stated, when one of these words is encountered, all of the relevant meanings are accessed regardless of the specific demands of the task and the base language that is being used. In the present, critical review, evidence purported to favor each view is presented along with a discussion of the methodological and analytic constraints that moderate the reported findings. The data lead to the conclusion that there is a time course involved in the activation of multiple meanings such that a primary or dominant meaning (sometimes biased by frequency) is typically accessed more readily, followed by the opposite language meaning. These results indicated that studies should focus on manipulating the timing intervals between the presentation of these words and subsequent responses that are required by a particular task.
Production of Subject-Verb Agreement in Spanish as a Second Language
Authors: Nicol Janet , Greth Delia
Published: July 2003

Abstract. In this paper, we report the results of a study of English speakers who have learned Spanish as a second language. All were late learners who have achieved near- advanced proficiency in Spanish. The focus of the research is on the production of subject-verb agreement errors and the factors that influence the incidence of such errors. There is some evidence that English and Spanish subject-verb agreement differ in susceptibility to interference from different types of variables; specifically, it has been reported that Spanish speakers show a greater influence of semantic factors in their implementation of subject-verb agreement ( Vigliocco, Butterworth, & Garrett, 1996 ). In our study, all participants were tested in English (L1) and Spanish (L2). Results indicate nearly identical error patterns: these speakers show no greater influence of semantic variables in the computation of agreement when they are speaking Spanish than when they are speaking English.
Comprehending Idioms Cross-Linguistically
Authors: Bortfeld Heather
Published: July 2003

Abstract. Speakers of three different languages (English, Latvian, and Mandarin) rated sets of idioms from their language for the analyzability of the relationship between each phrase’s literal and figurative meaning. For each language, subsets of idioms were selected based on these ratings. Latvian and Mandarin idioms were literally translated into English. Across three experiments, people classified idioms from the three languages according to their figurative meanings. Response times and error rates indicate that participants were able to interpret unfamiliar (e.g., other languages’) idioms depending largely on the degree to which they were analyzable, and that different forms of processing were used both within and between languages depending on this analyzability. Results support arguments for a continuum of analyzability ( Bortfeld & McGlone, 2001 ), along which figurative speech ranges from reflecting general conceptual structures to specific cultural and historical references.
Major nutrients and dissolved oxygen as indicators of the frontal zones in the Atlantic sector of the Southern Ocean
Authors: Dafner E. , Mordasova N. , Arzhanova N. , Maslennikov V. , Mikhailovsky Y. , Naletova I. , Sapozhnikov V. , Selin P. , Zubarevich V.
Published: July 2003

The chemical tracers of the main frontal zones of the Atlantic sector of the Southern Ocean are considered. Before the beginning of the spring bloom, frontal zones are distinguished by lateral gradients of dissolved oxygen, phosphate, nitrate, and silicate. During the spring bloom, the smoothing of nutrient concentrations on both sides of the fronts weakens lateral gradients of chemical properties. The position of surface gradients of nutrients within the Subtropical Frontal Zone (STFZ) does not coincide with the location of temperature and salinity gradients. As a result, fronts in this region have a stepped character. The best chemical indicator of the Northern STFZ front is the dissolved oxygen gradient, which coincides with the temperature and salinity gradients. The southern boundary of the STFZ is distinguished by the gradient of nitrate. The chemical criterion for identifying the Subantarctic Front is the gradient of oxygen, which ranges from 0.5 to 4.0 μmol kg−1 per km; the Polar Front is identified by the gradient of silicate (0.56 to 2.78 μM per km). At the surface, the Weddell‐Scotia Confluence (WSC) is distinguished not by the temperature and salinity, but by chemical parameters: The best year‐round criterion is the lateral gradient of silicate‐to‐phosphate atomic ratio, which ranges from 25 to 35. Other markers of the WSC are the gradients of silicate at the surface, oxygen at the upper boundary of the Circumpolar Deep Water, and the depths of its location.
Bio‐optical properties of the Labrador Sea
Authors: Cota Glenn F. , Harrison W. Glen , Platt Trevor , Sathyendranath Shubha , Stuart Venetia
Published: July 2003

Three cruises were conducted during fall and spring in the Labrador Sea to investigate the effects of bio‐optical properties on satellite retrievals of phytoplankton chlorophyll in this important high‐latitude ecosystem. Taxon‐specific and regional differences were found. Diatoms had ∼1.5 lower chlorophyll‐specific absorption but significantly higher reflectance ratios than prymnesiophytes. Particulate absorption at 443 nm for total, phytoplankton, and “detrital” fractions was related to chlorophyll, but values were lower than reported for lower latitudes. Decreased particulate absorption is attributed primarily to pigment packaging, while low backscattering to scattering ratios result from a lower relative abundance of bacteria and picophytoplankton with more large phytoplankton. Soluble absorption was not related to chlorophyll. A four‐component model with low, variable backscatter fractions and the observed absorption coefficients for phytoplankton, “detritus,” and soluble materials reproduces the measured reflectance spectra. Global chlorophyll algorithms tend to underestimate biomass at high latitudes, whereas regionally tuned algorithms provide more reliable retrievals. Taxon‐specific algorithms show promise, but given limited ranges, small sample sizes, and overlapping reflectance ratios they remain premature.
Photochemical and physical modeling of carbonyl sulfide in the ocean
Authors: von Hobe M. , Najjar R. G. , Kettle A. J. , Andreae M. O.
Published: July 2003

Carbonyl sulfide (COS) concentrations in the oceanic mixed layer were simulated using dynamic models that include parameterizations for photochemical and dark production, hydrolysis, air‐sea gas exchange, and vertical mixing. The results were compared with measurements taken at and below the ocean surface from four cruises. The description of the physics of vertical mixing and especially of the mixed layer depth has a great impact on model performance. A one‐dimensional K‐profile parameterization (KPP) model is shown to reproduce surface values quite accurately and to provide a reasonable approximation of the depth profiles. Surface values can also be approximated by a simple mixed‐layer box model, but the missing removal from the surface due to mixing and the integration over the entire mixed layer cause some significant deviations from the observations, especially when there are large diel variations in the mixed layer depth. Rate constants for COS photoproduction that were fitted by the models displayed pronounced regional differences, which are attributed to variations in the concentration of chromophoric dissolved organic matter (CDOM), the precursor for COS photoproduction. Overall, an approximately second‐order relationship between the photoproduction rate constant and the CDOM absorbance is observed in good agreement with the current mechanistic understanding of COS photoproduction. This relationship can help to improve the simulation of COS depth profiles by the KPP model, when information about the depth distribution of CDOM is available. Foremost, it may provide a key to upscaling the various local models to the regional or global scale, where the variability of COS production rates so far remains the biggest obstacle.
Bed load at low Shields stress on arbitrarily sloping beds: Alternative entrainment formulation
Authors: Parker Gary , Seminara Giovanni , Solari Luca
Published: July 2003

According to the Bagnold hypothesis for equilibrium bed load transport, a necessary constraint for the maintenance of equilibrium bed load transport is that the fluid shear stress at the bed must be reduced to the critical, or threshold, value associated with incipient motion of grains. It was shown in a companion paper [Seminara et al., 2002], however, that the Bagnold hypothesis breaks down when applied to equilibrium bed load transport on beds with transverse slopes above a relatively modest value that is well below the angle of repose. An investigation of this failure resulted in a demonstration of its lack of validity even for nearly horizontal beds. The constraint is here replaced with an entrainment formulation, according to which a dynamic equilibrium is maintained by a balance between entrainment of bed grains into the bed load layer and deposition of bed load grains onto the bed. The entrainment function is formulated so that the entrainment rate is an increasing function of the excess of the fluid shear stress at the bed over the threshold value. The formulation is implemented with the aid of a unique set of laboratory data that characterizes equilibrium bed load transport at relatively low shear stresses for streamwise angles of bed inclination varying from nearly 0° to 22°. The formulation is shown to provide a description of bed load transport on nearly horizontal beds that fits the data as well as that resulting from the Bagnold constraint. The entrainment formulation has the added advantage of not requiring the unrealistically high dynamic coefficient of Coulomb friction resulting from the Bagnold constraint. Finally, the entrainment formulation provides reasonable and consistent results on finite streamwise and transverse bed slopes, even those at which the Bagnold formulation breaks down completely.
Seasonal and interannual variability of sea‐surface carbon dioxide species at the European Station for Time Series in the Ocean at the Canary Islands (ESTOC) between 1996 and 2000
Authors: González‐Dávila Melchor , Santana‐Casiano J. Magdalena , Rueda Maria‐José , Llinás Octavio , González‐Dávila Enrique‐Francisco
Published: July 2003

Seasonal patterns in hydrography, partial pressure of CO2, fCO2, pHt, total alkalinity, AT, total dissolved inorganic carbon, CT, nutrients, and chlorophyll a were measured in surface waters on monthly cruises at the European Station for Time Series in the Ocean at the Canary Islands (ESTOC) located in the northeast Atlantic subtropical gyre. With over 5 years of oceanographic data starting in 1996, seasonal and interannual trends of CO2 species and air‐sea exchange of CO2 were determined. Net CO2 fluxes show this area acts as a minor source of CO2, with an average outgassing value of 179 mmol CO2 m−2 yr−1 controlled by the dominant trade winds blowing from May to August. The effect of short‐term wind variability on the CO2 flux has been addressed by increasing air‐sea fluxes by 63% for 6‐hourly sampling frequency. The processes governing the monthly variations of CT have been determined. From March to October, when CT decreases, mixing at the base of the mixed layer (11.5 ± 1.5 mmol m−3) is compensated by air‐sea exchange, and a net organic production of 25.5 ± 5.7 mmol m−3 is estimated. On an annual scale, biological drawdown accounts for the decrease in inorganic carbon from March to October, while mixing processes control the CT increase from October to the end of autumn. After removing seasonality variability, fCO2sw increases at a rate of 0.71 ± 5.1 μatm yr−1, and as a response to the atmospheric trend, inorganic carbon increases at a rate of 0.39 ± 1.6 μmol kg−1 yr−1.
New insights into Kilauea's volcano dynamics brought by large‐scale relative relocation of microearthquakes
Authors: Got Jean‐Luc , Okubo Paul
Published: July 2003

We investigated the microseismicity recorded in an active volcano to infer information concerning the volcano structure and long‐term dynamics, by using relative relocations and focal mechanisms of microearthquakes. There were 32,000 earthquakes of the Mauna Loa and Kilauea volcanoes recorded by more than eight stations of the Hawaiian Volcano Observatory seismic network between 1988 and 1999. We studied 17,000 of these events and relocated more than 70%, with an accuracy ranging from 10 to 500 m. About 75% of these relocated events are located in the vicinity of subhorizontal decollement planes, at a depth of 8–11 km. However, the striking features revealed by these relocation results are steep southeast dipping fault planes working as reverse faults, clearly located below the decollement plane and which intersect it. If this decollement plane coincides with the pre‐Mauna Loa seafloor, as hypothesized by numerous authors, such reverse faults rupture the pre‐Mauna Loa oceanic crust. The weight of the volcano and pressure in the magma storage system are possible causes of these ruptures, fully compatible with the local stress tensor computed by Gillard et al. [1996]. Reverse faults are suspected of producing scarps revealed by kilometer‐long horizontal slip‐perpendicular lineations along the decollement surface and therefore large‐scale roughness, asperities, and normal stress variations. These are capable of generating stick‐slip, large–magnitude earthquakes, the spatial microseismic pattern observed in the south flank of Kilauea volcano, and Hilina‐type instabilities. Rupture intersecting the decollement surface, causing its large‐scale roughness, may be an important parameter controlling the growth of Hawaiian volcanoes.
Gravitational core‐mantle coupling and the acceleration of the Earth
Authors: Rubincam David Parry
Published: July 2003

Gravitational core‐mantle coupling may be the cause of the observed variable acceleration of the Earth's rotation on the 1000‐year timescale. Density inhomogeneities which randomly come and go in the liquid outer core may gravitationally attract density inhomogeneities in the mantle (and crust), torquing the mantle and changing its rotation state. The corresponding torque by the mantle on the core may also explain the westward drift of the magnetic field of 0.2° yr−1. Gravitational core‐mantle coupling would stochastically affect the rate of change of the Earth's obliquity by just a few percent. Its contribution to polar wander would only be ∼0.5% the presently observed rate.
A numerical study of dense water outflows and halocline anticyclones in an arctic baroclinic slope current
Authors: Chao Shenn‐Yu , Shaw Ping‐Tung
Published: July 2003

We examine the relation between the dense water migration from the shelf to the deep ocean and offshore generation of halocline anticyclones in a physical setting appropriate for an Arctic baroclinic current system, using a nonhydrostatic numerical ocean model. The model basin contains an outer shelf connected to the deep sea by a continental slope. The ocean is cyclical in the alongshore direction. Sea surface is frictional to account for the ice‐exerted friction. A series of inflows and outflows is imposed on the shoreward side of the shelf to facilitate the release of dense waters into the basin. The distribution of inflow‐outflow is sinusoidal in the alongshore direction. Inflow carries dense water into the basin while the outflow withdraws ambient shelf water from the shelf. The multiple sources produce an array of dense plumes entering the shelf. Seaward migration of dense plumes is examined with and without an offshore baroclinic current bounded to the left by the shelf. The baroclinic current, if present, is supported by slanted isopycnals rising toward the shelf break. Without the baroclinic current, downslope sinking plumes veer to the right and produce an undercurrent trapped by the continental slope. With the baroclinic current, convection along slanted isopycnals can divert dense plumes away from boundary trapping and produce intense subsurface anticyclones offshore. Initial meanders embedded in the baroclinic current can trigger instabilities and also produce subsurface anticyclones offshore. However, disturbances induced by sinking plumes and instabilities of offshore origin generally do not interact constructively to intensify subsurface anticyclones offshore.
Modeling the baroclinic circulation in the area of the Sicily channel: The role of stratification and energy diagnostics
Authors: Napolitano Ernesto , Sannino Gianmaria , Artale Vincenzo , Marullo Salvatore
Published: July 2003

Aspects of the circulation of the Sicily channel region are studied with a high‐resolution, primitive equation, sigma coordinate model. This work is an attempt to study the process governing the purely baroclinic dynamics and its sensitivity to seasonal stratification, thus no atmospheric forcing is used. Two numerical experiments are analyzed using, as initial conditions, diagnostic velocity fields derived from the winter and summer climatological hydrologies. The quasi‐steady state is characterized by circulation patterns, in the depth range of the Modified Atlantic Water (MAW) and the Levantine Intermediate Water (LIW), strongly controlled by mesoscale eddies and topography. Seasonal difference is found in the surface current which exhibits the major variability on the African side, downstream of Adventure Bank and the Ionian Slope where the absolute maximum occurs. The intermediate circulation instead does not show relevant seasonal differences. LIW enters through the two passages south of Malta Plateau and preferentially flows along the Sicilian shelf edge exiting over the northern sill. Its pathway is strongly controlled by subsurface cyclonic and anticyclonic cells. The results are in good agreement with observations. An energy diagnostics is applied to model results and sheds important light on dynamical characteristics of the mesoscale eddy field and indicates seasonal differences in the energetic exchange with the mean flow. The analysis of the mean (MKE) and eddy (EKE) kinetic energy, the transfer terms between energy compartments and the eddy momentum flux divergence indicates how eddies are strongly energetic in summer and exchange energy more efficiently with the mean flow. In the quasi‐steady state MAW volume transport and MKE and EKE fluctuations are strongly correlated. This result suggests that mesoscale motions can control up to 40% of volume transport variability.
Exploring the potential of combining column‐integrated atmospheric polarization with airborne in situ size distribution measurements for the retrieval of an aerosol model: A case study of a biomass burning plume during SAFARI 2000
Authors: Elias Thierry , Piketh Stuart J. , Burger Roelof , Silva Ana Maria
Published: July 2003

Ground‐based columnar and airborne in situ measurements of aerosol optical properties acquired during the Southern African Regional Science Initiative (SAFARI 2000) in August–September 2000 are analyzed to retrieve the aerosol model of a haze layer affected by long‐range transport of biomass burning emissions. One case study is considered. A columnar value of the aerosol polarized phase function Qmeasp(Θ) and of the aerosol single scattering albedo ω0, both at 870 nm, are retrieved from measurements acquired by a ground‐based Sun/sky photometer, assuming that the surface albedo is 0.3. The maximum value of the polarized phase function is 0.37 ± 0.02 at a scattering angle of 70°, ω0 is 0.80 ± 0.05. The in situ particle size distribution is measured in a vertical profile over the ground‐based site by an airborne optical particle counter. Because the size distribution integrated over the column is inconsistent with the polarized phase function, aerosol concentration of the 0.25 μm mode is reduced by a factor of 7.5. Taking into account that the estimation of particle size depends on particle refractive index, it is found that the radius of absorbing particles cannot be larger than 0.15 μm for reproducing Qmeasp(Θ), suggesting external mixture of absorbing particles smaller than 0.15 μm with nonabsorbing particles larger than 0.15 μm. The imaginary part of the effective refractive index is estimated to be (0.09 ± 0.03)i. Comparing Ångström exponent obtained from Sun/sky photometer extinction measurements and the Ångström exponent calculated for the in situ measured aerosol size distribution acquired in eleven vertical profiles allows us to conclude that in most considered cases, the mixture of absorbing with nonabsorbing particles is external with a radius limit at around 0.15 μm.
Seasonal to interannual variability of vegetation and fires at SAFARI 2000 sites inferred from advanced very high resolution radiometer time series data
Authors: Anyamba A. , Justice C. O. , Tucker C. J. , Mahoney Robert
Published: July 2003

NOAA advanced very high resolution radiometer data are used to place the SAFARI 2000 and SAFARI 1992 intensive campaigns in the context of the interannual variability of vegetation conditions in southern Africa. Normalized difference vegetation index (NDVI) measurements and sea surface temperature (SST) indices of El Niño/Southern Oscillation (ENSO) are compared and the connections explained. The paper shows the vegetation evolution for the 2000 growing season, with unprecedented high and persistent NDVI anomalies associated with a cold phase of ENSO (La Niña) and above average rainfall between November and May, south of 15°S. In contrast, the 1992 season showed marked negative NDVI anomalies associated with an extreme drought in the southern part of the region, associated with the warm phase of ENSO (El Niño). These differences in NDVI patterns resulted in different patterns of fire distribution. More satellite detections of active fires were observed in 2000 than in 1992, especially for Botswana, Namibia, southern Zimbabwe, and southern Mozambique. Comparisons between in situ airborne measurements collected in 2000 and 1992 require an understanding of the extremely different vegetation and fire conditions associated with those years. Generalizations from results of the two SAFARI campaigns should be made with careful consideration of the extreme differences in conditions and the large interannual variability encountered in southern Africa, as depicted by the long‐term record of satellite vegetation measurements.
Viking‐era diurnal water‐ice clouds
Authors: Tamppari Leslie K. , Zurek R. W. , Paige D. A.
Published: July 2003

Water‐ice clouds during the Viking era are mapped as a function of season, latitude, longitude, and time of day. In the springtime hemisphere, where data are available, clouds are observed to decrease from morning to midday. They are observed to increase in extent from midday to afternoon, possibly due to increased atmospheric temperatures causing uplifting of dust which then acts as cloud condensation nuclei. During the summer hemisphere clouds are observed to decrease in extent throughout the day, indicating sufficient warming to prevent water reaching the condensation level. The Hadley cell upwelling branch is seen throughout the year via cloud belts in both the northern (aphelion cloud belt) and southern hemispheres in their respective springs and summers. Clouds extending equatorward of 60°N in late northern summer and early northern autumn are seen primarily over the Acidalia Planitia longitudinal sector and may indicate the southernmost extent of the north polar hood or clouds associated with storms. Water‐ice clouds associated with topographic features are seen, including Olympus Mons, the Tharsis volcanoes, and the northern rim of Hellas basin. There is little evidence for interannual variability in the prominent cloud features (e.g., the aphelion cloud belt) since they are present in both Martian years examined, though the detailed structure does change.