bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of major changes in flow regime on the macroinvertebrate assemblages of four chalk stream sites, 1997–2001
Authors: Wright J. F. , Clarke R. T. , Gunn R. J. M. , Kneebone N. T. , Davy‐Bowker J.
Published: August 2004

The macroinvertebrate assemblages of three unshaded sites on the River Kennet and one shaded site on the River Lambourn in Berkshire, England, were sampled in summer 1997–2001. Quantitative samples were taken on gravel and on the dominant macrophyte at each site in each year and abundance data were recorded for 57 families of macroinvertebrates. The study commenced during a major drought (1997), but in subsequent years discharge prior to sampling was much higher, culminating in the exceptionally high flows of spring 2001. Both family richness and abundance varied significantly in relation to site, habitat and year. Multidimensional scaling ordination, based on Bray‐Curtis dissimilarities, also displayed significant differences between sites, habitats and years. Differences in composition between the Kennet sites were partly due to longitudinal zonation whilst on the Lambourn, faunal differences resulted from shading and the addition of families from nearby habitats, including marginal vegetation. Major changes took place in family composition and abundance between the drought year of 1997 and 1998, indicating that faunal recovery from drought was rapid. Thereafter, faunal changes between 1998 and 2000 were relatively limited. In 2001, following the prolonged period of exceptionally high discharge, overall family richness peaked on both habitats at the three Kennet sites and family abundance reached peak or second highest values on all four sites and both habitats. Thus, the recent high discharge regimes experienced by these perennial chalk stream sites have had no immediate detrimental consequences for the macroinvertebrate assemblages. Copyright © 2004 John Wiley & Sons, Ltd.
The hydraulic impact and performance of a lowland rehabilitation scheme based on pool–riffle installation: the River Waveney, Scole, Suffolk, UK
Authors: Sear D. A. , Newson M. D.
Published: August 2004

Pool–riffle installation is increasingly becoming the standard form of river habitat enhancement undertaken, largely for the benefit of fisheries. This study documents the effect of riffle installation on the morphological and hydraulic diversity of a low gradient engineered river. Despite their prevalence there have to date been few published studies of the impacts of these features on channel hydraulics, despite concerns as to their potential impact on flood levels. In this paper the impacts of the installation of gravel bedforms on water surface elevations and flow resistance are considered. The performance of the riffle–pool sequences is assessed against a set of criteria derived from the scientific literature. The analysis reveals that the gravel bedforms do display the hydraulic functionality associated with natural pool–riffle sequences. At bankfull discharge, water surface elevation is not significantly increased over those existing prior to installation, and physical habitat is shown to be more diverse following rehabilitation. The stability and appropriate classification of the gravel bedforms created in the scheme are discussed, together with the implications for floodplain and river rehabilitation in general. Copyright © 2004 John Wiley & Sons, Ltd.
Effects of an enhanced flood on riparian plants of the River Murray, South Australia
Authors: Siebentritt Mark A. , Ganf George G. , Walker Keith F.
Published: August 2004

In October 2000, the flow of the River Murray entering South Australia was increased from 32 000 to 42 050 ML day−1 by release of water from an offstream reservoir, and a downstream weir was raised by 500 mm to impound the flood and enhance local floodplain inundation. The flood was maintained for about two weeks, although the duration of inundation was longer at low elevations on the floodplain. Vegetation at three sites was surveyed before and after the flood to examine the impact of inundation on the growth and germination of flood‐tolerant, flood‐dependent and flood‐intolerant species. Among 32 recorded species, Atriplex vesicaria (bladder saltbush, Chenopodiaceae), Sporobolus mitchellii (rats tail couch, Graminae) and Sarcocornia quinqueflora (samphire, Chenopodiaceae) accounted for nearly 82% of the total cover/abundance. Flood‐tolerant and flood‐dependent species (e.g. S. mitchellii) grew and germinated and flood‐intolerant species (e.g. A. vesicaria) senesced. No aquatic plants germinated or established, despite favourable conditions, suggesting an impoverished seed bank or grazing. Based on the growth but lack of germination of flood‐tolerant and flood‐dependent species, the value of small, occasional interventions in environmental flow management may be to maintain existing communities rather than restore degraded ones. Copyright © 2004 John Wiley & Sons, Ltd.
Effects of dykes on plant species composition in a large lowland river floodplain
Authors: Leyer Ilona
Published: August 2004

The effects of floodplain fragmentation by dykes on grassland vegetation were evaluated through field studies along the Middle Elbe River (federal states Saxony‐Anhalt and Brandenburg, Germany). Plant species composition was examined in 206 sites between 1996 and 1998 in the entire floodplain, which can be divided into the floodplain types ‘recent floodplain’, ‘older floodplain’ (which is separated from the recent one by dykes) and the ‘margin of the floodplain’ (which is the part of the older floodplain that forms the boundary and is furthest from the river). Dynamics in hydrology were examined weekly between November 1996 and February 1999 with the help of 40 water level wells which were installed near the studied sites. The hydrological parameters ‘average water level’, ‘average groundwater level’, ‘flooding duration’, ‘flooding depth higher 50 cm above soil surface’ and ‘standard deviation of the water level line’ were calculated to characterize the considered floodplain types and to relate species composition to hydrology. Furthermore several parameters of current management of the vegetation were recorded to evaluate the importance of land use versus hydrology for floodplain grasslands.

Detrended and canonical correspondence analysis (DCA, CCA) were used to identify major environmental gradients governing the vegetation and to determine if there is a relationship between the different locations within the floodplain, variation in species composition, and gradients of measured environmental variables.

The results indicate that the vegetation is closely related to a combination of water level fluctuations, which are different among the floodplain types, and soil moisture, while type and intensity of current management are not important in this context.

The results of contingency tables underline the significance of dykes for the occurrence and absence of individual species among the floodplain types. The observed patterns can also be explained by the different hydrological properties of the recent and older floodplain as the results of logistic regression reveal. Furthermore, disturbance and dispersal processes and their alteration by dykes have to be taken into account to explain the pattern of species occurrence.

Partial ordination detected residual differences in vegetation among the different floodplain types after accounting for the effects of the measured environmental variables. Grain size distribution is discussed as a further factor that might influence species composition. Copyright © 2004 John Wiley & Sons, Ltd.
Bank stabilization, riparian land use and the distribution of large woody debris in a regulated reach of the upper Missouri River, North Dakota, USA
Authors: Angradi Ted R. , Schweiger E. William , Bolgrien David W. , Ismert Peter , Selle Tony
Published: August 2004

Large woody debris (LWD) is an important component of ecosystem structure and function in large floodplain rivers. We examined associations between LWD distribution and riparian land use, bank stabilization (e.g. riprap revetment), local channel geomorphology, and distance downriver from the dam in the Garrison Reach, a regulated reach of the upper Missouri River in North Dakota, USA. We conducted a survey of shoreline‐associated LWD in the reach during typical summer flow conditions. Reach‐wide LWD density was 21.3 pieces km−1of shoreline, of which most pieces (39% ) were ‘beached’ between the waterline and the bankfull level, 31% of pieces had evidence of originating at their current location (anchored), 18% of pieces were in deep water (>1 m), and 13% were in shallow water. LWD density along unstabilized alluvial (sand/silt) shorelines (27.3 pieces km−1) was much higher than along stabilized shorelines (7.2 pieces km−1). LWD density along forested shorelines (40.1 pieces km−1) was higher than along open (e.g. rangeland, crop land; 9.2 pieces km−1) or developed (e.g. residential, industrial; 7.8 pieces km−1) shorelines. LWD density was highest overall along unstabilized, forested shorelines (45 pieces km−1) and lowest along open or developed shorelines stabilized with a blanket‐rock revetment (5.5 pieces km−1). Bank stabilization nearly eliminated the positive effect of riparian forest on LWD density. A predicted longitudinal increase in LWD density with distance from the dam was detected only for deep LWD (including snags) along unstabilized alluvial shorelines. Partial resurvey in the summer following the initial survey revealed a reduction in total LWD density in the reach that we attribute to an increase in summer flow between years. Changes in riparian management and land use could slow the loss of LWD‐related ecosystem services. However, restoration of a natural LWD regime in the Missouri River would require naturalization of the hydrograph and modification of existing bank stabilization and channel engineering structures. Copyright © 2004 John Wiley & Sons, Ltd.
Packaging software process improvement issues: a method and a case study
Authors: Gorschek Tony , Wohlin Claes
Published: August 2004

Software process improvement is a challenge in general and in particular for small‐ and medium‐sized companies. Assessment is one important step in improvement. However, given that a list of improvement issues has been derived, it is often very important to be able to prioritize the improvement proposals and also look at the potential dependencies between them. This paper comes from an industrial need to enable prioritization of improvement proposals and to identify their dependencies. The need was identified in a small‐ and medium‐sized software development company. Based on the need, a method for prioritization and identification of dependencies of improvement proposals was developed. The prioritization part of the method is based on a multi‐decision criteria method and the dependencies are identified using a dependency graph. The developed method has been successfully applied in the company, where people with different roles applied the method. The paper presents both the method as such and the successful application of it. It is concluded that the method worked as a means for prioritization and identification of dependencies. Moreover, the method also allowed the employees to discuss and reason about the improvement actions to be taken in a structured and systematic way. Copyright © 2004 John Wiley & Sons, Ltd.
Fetal gender and sonographic assessment of crown–rump length: implications for multifetal pregnancy reduction
Authors: Becker S. , Ural S. , Fehm T. , Bienstock J.
Published: August 2004

Objectives

Fetal size is a common criterion for the selection of an individual fetus to be reduced during multifetal pregnancy reduction. We investigated whether a difference in crown–rump length (CRL) exists between male and female fetuses at 9–13 weeks' gestation.

Methods

A total of 883 singleton pregnancies was evaluated at the time of chorionic villus sampling. The mean gestational age at the time of intervention was 10.9 weeks. Pregnancies were dated by certain last menstrual period (LMP). Pregnancies with uncertain dating by LMP or with a sonographic difference of gestational age > 1 week compared with LMP were excluded, as were all cases with chromosomal abnormalities. CRL differences between male and female fetuses were compared using Student's t‐test.

Results

A total of 417 female and 466 male fetuses fulfilled our study criteria. Their gestational ages ranged between 9.3 and 13.9 weeks. We found no significant difference in size between the male and female fetuses.

Conclusion

Using the CRL to guide multifetal pregnancy reduction should not result in a clinically significant selection of either gender. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Synthesis, Crystal Structures and Anticancer Activity of the New Chiral Mono‐ and Dinuclear Palladium(II) Complexes derived from (S)‐(‐)‐(1‐phenylethylimino)benzylphenylketone
Authors: Peláez Ma. Angeles , Ramírez Teresa , Martínez Marcos , Sharma Pankaj , Álvarez Cecilio , Gutiérrez René
Published: August 2004

The enantiopure ketoimine of benzil – the (S)‐(‐)‐(1‐phenylethylimino)benzyl phenyl ketone (1) obtained under microwave irradiation in solvent‐free conditions – reacts with Na2[PdCl4] to give the new chiral mono‐ and dinuclear Pd‐complexes 2 and 3, which have been partly characterized by IR, 1H and 13C NMR spectroscopies along with MS‐FAB+ spectrometry. The crystal and molecular structures of both complexes has been fully confirmed by single‐crystal X‐ray studies. On the other hand, investigations in vitro of 2 and 3 have displayed growth inhibition against different classes of cancer: leukemia (K‐562 CML), colon cancer (HCT‐15), cancer breast (MCF‐7), central nervous system (U‐251 Glio) and prostate cancer (PC‐3) cell lines.
An Evaluation of Ligand Properties of Neutral and Anionic Tris(imidazol‐2‐yl)phosphines
Authors: Enders Markus , Fritz Olaf , Pritzkow Hans
Published: August 2004

In order to study the applicability of tris(imidazol‐2‐yl)phosphine (PIm3) as a possible charge‐variable ligand, new neutral N‐butyl and N‐benzyl derivatives and d0‐metal complexes thereof were prepared and characterized as reference compounds for planned complexes with high valent metals. In addition, an anionic ligand precursor was characterized by X‐Ray analysis and its reactivity towards transition metal halides assayed.
Synthese, Strukturen und X‐/Q‐Band‐EPR‐Untersuchungen von N,N‐Diethyl‐N′‐3,5‐di(trifluormethyl)benzoylthioureato‐Komplexen des CuII, NiII und PdII sowie EPR‐spektroskopische Charakterisierung eines CuII‐CuII‐Dimers
Authors: Kampf Michael , Richter Rainer , Gerber Stefan , Kirmse Reinhard
Published: August 2004

Die Synthese und die Kristallstrukturen des Liganden N,N‐Diethyl‐N′‐3,5‐di(trifluormethyl)benzoylthioharnstoff HEt2dtfmbtu sowie dessen NiII‐ und PdII‐Komplexes werden berichtet. Der Ligand koordiniert zweizähnig unter Bildung von Bischelaten. Der NiII‐ und der PdII‐Komplex sind isostrukturell. Der ebenfalls hergestellte CuII‐Komplex konnte nicht strukturell charakterisiert werden. Die Präparation diamagnetisch verdünnter, für EPR‐spektroskopische Untersuchungen geeigneter Pulverproben vom Typ Cu/Ni(Et2dtfmbtu)2 und Cu/Pd(Et2dtfmbtu)2 gelingt jedoch. Die EPR‐Spektren zeigen deutliche Unterschiede für die Symmetrie der CuS2O2‐Einheit in den Cu/Ni und Cu/Pd‐Systemen: Während für das Cu/Pd‐System axial‐symmetrische Tensoren g und ACu beobachtet werden, sind beide Tensoren für das Cu/Ni‐System deutlich rhombisch. In gefrorener Lösung (Lösungsmittel Chloroform) des CuII‐Komplexes wird EPR‐spektroskopisch interessanterweise erstmals das Vorliegen eines CuII‐CuII‐Dimers für die Substanzklasse der Acylthioureato‐CuII‐Komplexe beobachtet. Die erhaltenen Parameter des Feinstrukturtensors werden zur Bestimmung des CuII‐CuII‐Abstands verwendet.
Heterobimetallic Nickel(II) Complexes of Ferrocenyldithiophosphonates. Molecular Structures of [{FcP(OR)S2}2Ni] [Fc = Fe(η5‐C5H4)(η5‐C5H5), R = Et, Pri, Bus, Bui]
Authors: Karakus Mehmet , Lönnecke Peter , Yakhvarov Dmitry , Hey‐Hawkins Evamarie
Published: August 2004

The reaction of 2,4‐diferrocenyl‐1,3‐dithiadiphosphetane 2,4‐disulfide [FcPS(μ‐S)]2 [Fc = Fe(η5‐C5H4)(η5‐C5H5)] with alcohols ROH gave the corresponding ferrocenyldithiophosphonic acids [FcPS(OR)(SH)], which were treated in situ with Ni(CH3COO)2·4H2O in acetic acid to yield the square‐planar heterobimetallic trinuclear complexes [{FcP(OR)S2}2Ni] (R = Me (1), Et (2), Pri (3), Bus (4) and Bui (5)). Compounds 1‐5 were characterized by elemental analysis, MS, NMR (1H, 13C and 31P), IR spectroscopy, and 2‐5 also by X‐ray crystallography. Cyclovoltammetric studies on the heterobimetallic nickel(II) complexes 1‐5 showed irreversible reduction to unstable nickel(I) complexes and an irreversible two‐electron oxidation of the sulfur‐containing nickel fragments, followed by a reversible one‐electron oxidation of the two ferrocenyl groups.
Postdisaster PTSD over four waves of a panel study of Mexico's 1999 flood
Authors: Norris Fran H. , Murphy Arthur D. , Baker Charlene K. , Perilla Julia L.
Published: August 2004

Samples of adults representative of Tezuitlán, Puebla and Villahermosa, Tobasco (combined N = 561), were interviewed 6, 12, 18, and 24 months after the devastating 1999 floods and mudslides in Mexico. Current DSM‐IV PTSD and major depressive disorder (MDD) were assessed with the Composite International Diagnostic Interview. At Wave 1, PTSD was highly prevalent (24% combined), especially in Tezuitlán (46%), which had experienced mass casualties and displacement. Both linear and quadratic effects of time emerged, as PTSD symptoms initially declined but subsequently stabilized. Differences between cities lessened as time passed. Comorbidity between PTSD and MDD was substantial. The findings demonstrate that the international health community needs to be prepared for epidemics of PTSD when disasters strike developing areas of the world.
A mediational model of PTSD in World War II veterans exposed to mustard gas
Authors: Jankowski M. Kay , Schnurr Paula P. , Adams Gary A. , Green Bonnie L. , Ford Julian D. , Friedman Matthew J.
Published: August 2004

Structural equation modeling (SEM) was used to examine associations among trauma‐related‐contextual factors, initial psychological reactions, social support, and subsequent disclosure on posttraumatic stress disorder (PTSD) symptoms in a sample of World War II (WWII) veterans exposed to mustard gas (N = 305). A structural model suggested that initial psychological reaction mediated the relationship between variables related to the context of mustard gas exposure and severity of PTSD symptoms 50 years later. Unexpectedly, social support appeared to be positively related to PTSD symptoms, and not related to the contextual variables or initial psychological reactions. These findings contribute to our understanding of PTSD in older veterans, and have relevance for early intervention services to prevent PTSD among those at risk for exposure to toxic agents.
Evaluation of initial posttrauma cardiovascular levels in association with acute PTSD symptoms following a serious motor vehicle accident
Authors: Buckley Beth , Nugent Nicole , Sledjeski Eve , Raimonde A. Jay , Spoonster Eileen , Bogart Laura M. , Delahanty Douglas L.
Published: August 2004

The present study examined the relationship between heart rate (HR) and blood pressure (BP) levels assessed at multiple time points posttrauma and subsequent acute posttraumatic stress disorder (PTSD) symptoms present at a 1‐month follow‐up. HR and BP levels were measured in 65 motor vehicle accident (MVA) survivors during Emergency Medical Service transport, upon admission to the trauma unit. For the first 20 min postadmission and on the day of discharge. Hierarchical linear modeling analyses revealed no significant relationships between cardiovascular levels and acute PTSD symptoms. Given the small sample size, these results should be interpreted with caution. However, the present results question the use of initial cardiovascular levels as predictors of subsequent acute PTSD in seriously injured MVA victims.
Cognitive–behavioral couple's treatment for posttraumatic stress disorder: Initial findings
Authors: Monson Candice M. , Schnurr Paula P. , Stevens Susan P. , Guthrie Karen A.
Published: August 2004

This pilot study was an initial investigation of Cognitive–Behavioral Couple's Treatment (CBCT) for posttraumatic stress disorder (PTSD). Seven couples in which the husband was diagnosed with PTSD secondary to Vietnam combat experiences completed the treatment. According to independent clinician assessment and partner report, the veterans had substantial improvements in their PTSD symptoms. The veterans reported less dramatic improvements in their PTSD symptoms, but endorsed significant improvements in their depression and anxiety. The partners reported improved relationship satisfaction, whereas the veterans' relationship satisfaction was unchanged across treatment. The current findings are compared with findings on other forms of empirically validated treatment for PTSD and previous studies of CBCT for various individual problems. Theoretical implications and future directions are offered.
Social acknowledgment as a victim or survivor: A scale to measure a recovery factor of PTSD
Authors: Maercker Andreas , Müller Julia
Published: August 2004

The development and validation of a new measure of social acknowledgment as a victim or survivor is presented, whose items were derived from previous research on social recovery factors of post‐traumatic stress disorder. The Social Acknowledgment Questionnaire (SAQ) was administered to nontreatment seeking traumatized persons—178 former political prisoners in East Germany and 151 recently traumatized interpersonal crime victims. Principal components analysis yielded three factors—Recognition as victim, General disapproval, and Family disapproval. The factors showed high internal consistency and good test‐retest reliability; correlated moderately to strong with measures of PTSD severity, social support, and reluctance to talk about the trauma. In comparison to a conventional measure of social support, the SAQ predicted comparably better between persons with high‐ and low‐PTSD severity.
Are reports of posttraumatic growth positively biased?
Authors: Smith Sharon G. , Cook Sarah L.
Published: August 2004

This study examines positivity bias in reports of growth following exposure to traumatic events. Participants (N = 276) from an urban university and a superior court jury pool were randomly assigned to one of two methodological groups. In one, participants responded to the Posttraumatic Growth Inventory (PTGI) in relation to a specific stressful event. In the other, PTGI questions were not linked to specific events. Findings indicate that current methods for assessing posttraumatic growth (PTG) may actually underestimate growth. That is, linking questions about growth to specific stressors may have led participants to be cautious about attributing their growth experiences to a traumatic event. These findings contradict notions that current methods of measuring PTG create a positivity bias. Suggestions for future research include the use of prospective designs and corroborating reports of growth.
Structure and evolution of the East Sierran thrust system, east central California
Authors: Dunne George C. , Walker J. Douglas
Published: August 2004

A belt of arc‐parallel, northeast vergent contractional deformation, the East Sierran thrust system (ESTS), crops out for ∼150 km along the east side of the Sierran continental margin arc. The ESTS is nowhere wider than ∼20 km, and it accommodated an estimated minimum of ∼9.3 km of horizontal shortening. Remarkably, it experienced repeated episodes of broadly coaxial and coaxial‐planar contractional deformation beginning prior to 188 Ma and continuing past 140 Ma. We postulate that the ESTS resulted primarily from episodic underthrusting of the back arc lithosphere beneath the east edge of the Sierran arc, facilitated by a buttressing effect of the arc. As a result of this process, rocks along the east flank of the batholith, including the ESTS, were episodically shortened against the arc buttress. The ESTS experienced significant deformation during the Nevadan orogeny, indicating that contractional to transpressive deformation affiliated with this event affected the eastern wall rocks of the arc as well as its western wall rocks.
A 3‐D model analysis of the slowdown and interannual variability in the methane growth rate from 1988 to 1997
Authors: Wang James S. , Logan Jennifer A. , McElroy Michael B. , Duncan Bryan N. , Megretskaia Inna A. , Yantosca Robert M.
Published: August 2004

Methane has exhibited significant interannual variability with a slowdown in its growth rate beginning in the 1980s. We use a 3‐D chemical transport model accounting for interannually varying emissions, transport, and sinks to analyze trends in CH4 from 1988 to 1997. Variations in CH4 sources were based on meteorological and country‐level socioeconomic data. An inverse method was used to optimize the strengths of sources and sinks for a base year, 1994. We present a best‐guess budget along with sensitivity tests. The analysis suggests that the sum of emissions from animals, fossil fuels, landfills, and wastewater estimated using Intergovernmental Panel on Climate Change default methodology is too high. Recent bottom‐up estimates of the source from rice paddies appear to be too low. Previous top‐down estimates of emissions from wetlands may be a factor of 2 higher than bottom‐up estimates because of possible overestimates of OH. The model captures the general decrease in the CH4 growth rate observed from 1988 to 1997 and the anomalously low growth rates during 1992–1993. The slowdown in the growth rate is attributed to a combination of slower growth of sources and increases in OH. The economic downturn in the former Soviet Union and Eastern Europe made a significant contribution to the decrease in the growth rate of emissions. The 1992–1993 anomaly can be explained by fluctuations in wetland emissions and OH after the eruption of Mount Pinatubo. The results suggest that the recent slowdown of CH4 may be temporary.
Comparison of global climatological maps of sea surface dimethyl sulfide
Authors: Belviso S. , Bopp L. , Moulin C. , Orr J. C. , Anderson T. R. , Aumont O. , Chu S. , Elliott S. , Maltrud M. E. , Simó R.
Published: August 2004

We have examined differences in regional and seasonal variability among seven global climatologies of sea‐surface dimethyl sulfide (DMS) concentrations. We found large differences between recent climatologies and that typically used by most atmospheric sulfur models. The relative uncertainty (1σ/mean) in the latitudinal distribution of the annual mean DMS concentration increases from about 50% in tropical and temperate regions to nearly 100% in the high latitudes. We also compared these climatologies to new measurements in the North Atlantic Ocean taken during the 2001 Programme Océan Multidisciplinaire Méso Echelle (POMME) expeditions.
Dissolved and particulate organic carbon in the Sea of Okhotsk: Transport from continental shelf to ocean interior
Authors: Nakatsuka Takeshi , Toda Mari , Kawamura Kimitaka , Wakatsuchi Masaaki
Published: August 2004

Dissolved and particulate organic carbon (DOC and POC) were measured in water columns of the Sea of Okhotsk together with other hydrological and chemical properties, including phytoplankton pigments (Chl‐a) and stable carbon isotopic ratios (δ13C) of POC. Transects from shelf to slope off the northeast coast of Sakhalin showed the existence of a cold‐water mass in the intermediate layer on the slope area having a density of 26.7–27.0 σθ, which is equivalent to the cold and dense water on the shelf (dense shelf water: DSW). The cold intermediate water mass was rich in DOC, POC, and Chl‐a, and the δ13C of POC was high, similar to that in DSW, indicating that the organic matter in the cold intermediate water is exported from the highly productive shelf area by the outflow of DSW. On the other hand, surface waters near the coast of northern Sakhalin had a very low salinity, which must be affected by the fresh water discharge from the Amur River. The low‐salinity water contained a large amount of DOC that was more than 3 times greater than the pelagic surface waters. The linear regression line between the salinity and the DOC in the surface layer of the studied area indicates that the Amur River water contains approximately 690 μM of DOC, and the input of DOC from the Amur to the Sea of Okhotsk was estimated to be approximately 2.5 TgC/yr. The relationships between the temperature and the DOC and POC along a density surface from 26.7 to 27.0 σθ suggest that DOC and POC in the DSW are transported into the intermediate layer of the pelagic region without being removed at the shelf edge. Simple estimates for additions of organic carbon into the intermediate layer of the area off the east coast of Sakhalin suggests that DSW outflow from the shelf brings into this layer approximately 13.6 and 0.9 TgC/yr of DOC and POC, respectively. These fluxes are much larger than the sinking POC flux from the in situ surface water, and so are fundamental in characterizing the biogeochemical cycles in the Sea of Okhotsk.
Air‐sea gas transfer: Its dependence on wind stress, small‐scale roughness, and surface films
Authors: Frew Nelson M. , Bock Erik J. , Schimpf Uwe , Hara Tetsu , Haußecker Horst , Edson James B. , McGillis Wade R. , Nelson Robert K. , McKenna Sean P. , Uz B. Mete , Jähne B.
Published: August 2004

The influence of wind stress, small‐scale waves, and surface films on air‐sea gas exchange at low to moderate wind speeds (<10 m s−1) is examined. Coincident observations of wind stress, heat transfer velocity, surface wave slope, and surface film enrichments were made in coastal and offshore waters south of Cape Cod, New England, in July 1997 as part of the NSF‐CoOP Coastal Air‐Sea Chemical Fluxes study. Gas transfer velocities have been extrapolated from aqueous heat transfer velocities derived from infrared imagery and direct covariance and bulk heat flux estimates. Gas transfer velocity is found to follow a quadratic relationship with wind speed, which accounts for ∼75–77% of the variance but which overpredicts transfer velocity in the presence of surface films. The dependence on wind stress as represented by the friction velocity is also nonlinear, reflecting a wave field‐dependent transition between limiting transport regimes. In contrast, the dependence on mean square slope computed for the wave number range of 40–800 rad m−1 is found to be linear and in agreement with results from previous laboratory wind wave studies. The slope spectrum of the small‐scale waves and the gas transfer velocity are attenuated in the presence of surface films. Observations over large‐scale gradients of biological productivity and dissolved organic matter show that the reduction in slope and transfer velocity are more clearly correlated with surface film enrichments than with bulk organic matter concentrations. The mean square slope parameterization explains ∼89–95% of the observed variance in the data and does not overpredict transfer velocities where films are present. While the specific relationships between gas transfer velocity and wind speed or mean square slope vary slightly with the choice of Schmidt number exponent used to scale the heat transfer velocities to gas transfer velocities, the correlation of heat or gas transfer velocity with mean square slope is consistently better than with wind speed.
On the forcing of sea level in the Black Sea
Authors: Tsimplis M. N. , Josey S. A. , Rixen M. , Stanev E. V.
Published: August 2004

Forcing mechanisms for sea level variability in the Black Sea are investigated in the context of an observed increase in the sea level of this basin by 2.5 mm/yr over the last 60 years. Temperature and salinity variations computed from the Mediterranean Data Archeology and Rescue (MEDAR) data set exhibit significant interdecadal variability. However, the corresponding steric height variation does not show a long‐term increase and thus cannot account for the observed change in sea level. The impact of surface freshwater flux (P‐E) changes is also investigated using two independent data sets. The first data set, which is based on measurements collected in the basin, can explain most of the sea level variability, with only 0.8 mm/yr remaining unexplained. The second data set, output from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis, is unable to explain any of the observed trend. Potential contributions from changes in river runoff and surface pressure are quantified but found to be minor terms. By comparing the observed salinity changes with the sea level rise and the P‐E variability in the first data set, we infer that the P‐E variations are the primary cause for the observed sea level rise, while land movements are likely to partly contribute, too. The relationship of Black Sea temperature and salinity variability with corresponding variability in the connected Aegean Sea has also been explored. A significant correlation is found between the salinity of the upper water of the Aegean Sea and the layer between 50 and 300 m in the Black Sea, indicating that the latter layer is a product of the Mediterranean inflow.
Islands as miniature continents: Another look at the land‐ocean lightning contrast
Authors: Williams Earle , Chan Twiggy , Boccippio Dennis
Published: August 2004

Numerous observations substantiate a pronounced contrast in lightning activity between continents and oceans. The traditional explanation for continental dominance is based on a contrast in thermal properties of land and sea. A more recent idea is based on the contrast in boundary layer aerosol concentration between land and sea. This study makes use of islands as miniature continents of varying area to distinguish between these two hypotheses. Scaling law analysis is used to predict transitional island areas for the two hypotheses. NASA Tropical Rainfall Measuring Mission satellite observations provide a uniform data set on island activity. The island area dependences of lightning activity are more consistent with the thermal hypothesis than the aerosol hypothesis, but this conclusion must be tempered with the extreme simplification of the theoretical predictions.
Mercury in the atmosphere around Japan, Korea, and China as observed during the 2001 ACE‐Asia field campaign: Measurements, distributions, sources, and implications
Authors: Friedli Hans R. , Radke Lawrence F. , Prescott Ryan , Li Pan , Woo Jung‐Hun , Carmichael Gregory R.
Published: August 2004

We report on mercury in the atmosphere of east Asia (Japan, Korea, and China) as measured from sea level to ∼7000 m during 16 research flights in the National Science Foundation (NSF)/National Center for Atmospheric Research (NCAR) C‐130 aircraft during the Asian Pacific Regional Aerosol Characterization Experiment (ACE‐Asia) campaign (http://saga.pmel.noaa.gov/aceasia/). The air at all altitudes contained concentrations of atmospheric mercury above the global background. The atmosphere was highly stratified with plumes originating from massive dust storms carried out of China, from local industrial pollution, from volcanoes, and, less well defined, from biomass burning. Most often the air masses were mixtures, e.g., dust layers contained anthropogenic emissions or volcanic plumes were embedded in anthropogenic pollution; thus the total data set showed no significant correlations of gaseous mercury with the most common anthropogenic pollutants in the area (CO and SO2), but good correlations were observed for identifiable plumes. Highest mixing ratios for gaseous elemental mercury (GEM) were found in industrial plumes exiting China (∼6.3 ng/m3), Korea (∼3 ng/m3), and Japan (∼3 ng/m3). The core of the plume from Miyake Jima volcano contained ∼3.7 ng/m3 of GEM. Crustal mercury was also present, emitted and subsequently deposited during the outbreak of the spring dust storms. Some of the nondust aerosols contained soluble mercury in highly variable ratios with the gas‐phase mercury contained in the same plume. Preliminary estimates for the export from China are 5–15 t of crustal mercury during the dust storms, ∼150 t/yr of gas‐phase mercury from biomass/biofuel combustion, and ∼600 t/yr from industrial sources, mostly from coal combustion. Gaseous mercury is a useful tracer for industrial, volcanic, and biomass‐burning sources, but in most cases, robust plume identification required one or more cotracers. Because of the inertness of GEM and the ease of its measurement it is well suited for the tracking of long‐range transport.
Quasi‐biennial oscillation and quasi‐biennial oscillation–annual beat in the tropical total column ozone: A two‐dimensional model simulation
Authors: Jiang Xun , Camp Charles D. , Shia Runlie , Noone David , Walker Christopher , Yung Yuk L.
Published: August 2004

The National Centers for Environmental Prediction–Department of Energy Reanalysis 2 data are used to calculate the monthly mean meridional circulation and eddy diffusivity from 1979 to 2002 for use in the California Institute of Technology–Jet Propulsion Laboratory two‐dimensional (2‐D) chemistry and transport model (CTM). This allows for an investigation of the impact of dynamics on the interannual variability of the tropical total column ozone for all years for which the Total Ozone Mapping Spectrometer and the Solar Backscatter Ultraviolet merged total ozone data are available. The first two empirical orthogonal functions (EOFs) of the deseasonalized and detrended stratospheric stream function capture 88% of the total variance on interannual timescales. The first EOF, accounting for over 70% of the interannual variance, is related to the quasi‐biennial oscillation (QBO) and its interaction with annual cycles, the QBO‐annual beat (QBO‐AB). The 2‐D CTM provides realistic simulations of the seasonal and interannual variability of ozone in the tropics. The equatorial ozone anomaly from the model is close to that derived from the observations. The phase and amplitude of the QBO are well captured by the model. The magnitude of the QBO signal is somewhat larger in the model than it is in the data. The QBO‐AB found in the simulated ozone agrees well with that in the observed data.
Global radiative forcing of coupled tropospheric ozone and aerosols in a unified general circulation model
Authors: Liao Hong , Seinfeld John H. , Adams Peter J. , Mickley Loretta J.
Published: August 2004

Global simulations of sea salt and mineral dust aerosols are integrated into a previously developed unified general circulation model (GCM), the Goddard Institute for Space Studies (GISS) GCM II′, that simulates coupled tropospheric ozone‐NOx‐hydrocarbon chemistry and sulfate, nitrate, ammonium, black carbon, primary organic carbon, and secondary organic carbon aerosols. The fully coupled gas‐aerosol unified GCM allows one to evaluate the extent to which global burdens, radiative forcing, and eventually climate feedbacks of ozone and aerosols are influenced by gas‐aerosol chemical interactions. Estimated present‐day global burdens of sea salt and mineral dust are 6.93 and 18.1 Tg with lifetimes of 0.4 and 3.9 days, respectively. The GCM is applied to estimate current top of atmosphere (TOA) and surface radiative forcing by tropospheric ozone and all natural and anthropogenic aerosol components. The global annual mean value of the radiative forcing by tropospheric ozone is estimated to be +0.53 W m−2 at TOA and +0.07 W m−2 at the Earth's surface. Global, annual average TOA and surface radiative forcing by all aerosols are estimated as −0.72 and −4.04 W m−2, respectively. While the predicted highest aerosol cooling and heating at TOA are −10 and +12 W m−2, respectively, surface forcing can reach values as high as −30 W m−2, mainly caused by the absorption by black carbon, mineral dust, and OC. We also estimate the effects of chemistry‐aerosol coupling on forcing estimates based on currently available understanding of heterogeneous reactions on aerosols. Through altering the burdens of sulfate, nitrate, and ozone, heterogeneous reactions are predicted to change the global mean TOA forcing of aerosols by 17% and influence global mean TOA forcing of tropospheric ozone by 15%.
Application of a bias estimator for the improved assimilation of Measurements of Pollution in the Troposphere (MOPITT) carbon monoxide retrievals
Authors: Lamarque J.‐F. , Khattatov B. , Yudin V. , Edwards D. P. , Gille J. C. , Emmons L. K. , Deeter M. N. , Warner J. , Ziskin D. C. , Francis G. L. , Ho S. , Mao D. , Chen J. , Drummond J. R.
Published: August 2004

This study discusses an improved technique for the assimilation of carbon monoxide retrievals from the Measurements of Pollution in the Troposphere (MOPITT) instrument in a chemistry‐transport model using a suboptimal Kalman filter. An online bias estimator algorithm is employed to identify systematic biases in the model and account for them during the assimilation. Results suggest a large decline (both locally and globally) in the observation minus forecast diagnostics and provide insights about possible model deficiencies by enabling explicit examination of model biases.
Characterizing a coastal karst aquifer using an inverse modeling approach: The saline springs of Thau, southern France
Authors: Pinault J.‐L. , Doerfliger N. , Ladouche B. , Bakalowicz M.
Published: August 2004

A methodological approach using inverse modeling was used to characterize the functioning of the deep and shallow reservoirs of the Thau karst aquifer system. Three springs were monitored at the convergence of rising saline water diluted with shallow groundwater in karst conduits and unmixed shallow groundwater that behaves as confined groundwater. In such a method, impulse responses of flow and fluxes are combined in order to separate hydrographs. The model explains the salinity and hydraulic head variations of the submarine and inland springs. It confirms and improves the conceptual model of this groundwater system in which mixing of saline and subsurface waters occurs. The different forces driving the upward flowing mixed water into the drainage axis and faults were studied in order to elucidate the springs' functioning. A comparative study of spring functioning is proposed, which clearly shows the very high sensitivity of the groundwater system to changes in recharge and discharge conditions.
Temporal variations of fluxes of NO, NO2, N2O, CO2, and CH4 in a tropical rain forest ecosystem
Authors: Butterbach‐Bahl Klaus , Kock Martin , Willibald Georg , Hewett Bob , Buhagiar Spiro , Papen Hans , Kiese Ralf
Published: August 2004

Fluxes of N2O, NO, NO2, CO2, and CH4 were measured with high temporal resolution for 3 months at a tropical rain forest site in Queensland, Australia, using automated measuring systems. During this period, representing the transition between dry and wet season, huge pulses of NO emissions from the soil exceeding 500 μg N m−2 h−1 were observed with the onset of the first rainfalls. The magnitude of fluxes was explained by intensive mineralization of accumulated litter from a previous long‐lasting dry period. The mean NO emission rate was 207.1 μg N m−2 h−1 (range: 0.1–773.8 μg N m−2 h−1) and thus ∼8 times higher as compared to N2O emissions (25.6 μg N m−2 h−1, range: 0–101.3 μg N m−2 h−1). NO and N2O emissions showed pronounced temporal variations, which were almost exclusively triggered by changes in soil moisture. Total NO and N2O losses summed to ∼3.5 kg N ha−1. Though a significant amount of the NO emitted from the soil was redeposited to the soil surface after its oxidation to NO2 (0.7 kg N ha−1), the observed magnitude of net NOx release from the soil indicates that NOx emissions from tropical rain forest ecosystems are seriously underestimated. The mean CO2 emission was 159.0 mg C m−2 h−1 (range: 36.3–284.8 mg C m−2 h−1) and thus >2 magnitudes higher than NO emissions. Among the C‐ and N‐trace gases measured, the temporal variability of CH4 uptake was the lowest. The mean uptake rate for CH4 was −23.8 μg C m−2 h−1 (range: −50.0–0 μg C m−2 h−1). The emission ratios of NO:N2O, CO2:N2O and CO2:NO varied substantially with time. During dry periods the NO‐N:N2O‐N ratio was as high as 60:1, whereas for wetter periods it decreased to <7:1. A comparable trend was also observed for the ratio between CO2‐C:N2O‐N emissions. The largest ratio of CO2‐C:NO‐N (>1500:1) was observed at intermediate soil moisture values.
Latitudinal dependence of low cloud amount on cosmic ray induced ionization
Authors: Usoskin I. G. , Marsh N. , Kovaltsov G. A. , Mursula K. , Gladysheva O. G.
Published: August 2004

A significant correlation between the annual cosmic ray flux and the amount of low clouds has recently been found for the past 20 years. However, of the physical explanations suggested, none has been quantitatively verified in the atmosphere by a combination of modelling and experiment. Here we study the relation between the global distributions of the observed low cloud amount and the calculated tropospheric ionization induced by cosmic rays. We find that the time evolution of the low cloud amount can be decomposed into a long‐term trend and inter‐annual variations, the latter depicting a clear 11‐year cycle. We also find that the relative inter‐annual variability in low cloud amount increases polewards and exhibits a highly significant one‐to‐one relation with inter‐annual variations in the ionization over the latitude range 20–55°S and 10–70°N. This latitudinal dependence gives strong support for the hypothesis that the cosmic ray induced ionization modulates cloud properties.
Generation of interannual and interdecadal climate oscillations through nonlinear subharmonic resonance in delayed oscillators
Authors: Minobe Shoshiro , Jin Fei‐fei
Published: August 2004

The resonant behavior of delayed oscillators is studied using two simple prototype equations similar to that used by Suarez and Schopf. One prototype equation has a periodic modulation of simultaneous feedback, and the other prototype equation has a periodic external forcing term. The periodic modulation yields even‐multiple resonance to the modulation periods, while the periodic forcing results in odd‐multiple resonance to the forcing periods. The reason why these two‐types of resonance occur in each system is explained. The key mechanism for the resonance is that a positive simultaneous feedback for small amplitudes sets a threshold. Only when the sum of non‐simultaneous terms is larger than the threshold, a phase reversal can take place. The implications of El Niño elimination due to annual cycle and potential importance for the decadal variability are discussed.
Near bottom currents and their relation to the transport in the Kuroshio Extension
Authors: Yoshikawa Yasushi , Church John A. , Uchida Hiroshi , White Neil J.
Published: August 2004

Near bottom current structure in the area of the Kuroshio Extension is examined using Lowered ADCP data obtained along 146°25′E and 152°30′E. The flow of the Kuroshio Extension reaches the ocean floor with a shift of the current to the right with depth. The near bottom currents have speeds of over 10 cm/s. Westward deep counter currents are observed to the north and south of the near bottom Kuroshio Extension. The eastward Kuroshio Extension transport is 163 Sv across 146°25′E and 113 Sv across 152°30′E, larger than previous studies because the contribution of the barotropic flow is twice that of the geostrophic flow. The downstream variation of the transport suggests the Kuroshio Extension strength increases after separating from the coast of Japan and decreases before 152°30′E. However, temporal variability could also contribute to the different transport estimates.