Institutionalizing the High North: Will the harvest of redfeed be a critical juncture for the solidification of the Svalbard Fisheries Protection Zone?     

Rachel Tiller 《Ocean & Coastal Management》2011,54(5):374-380

The Svalbard Fisheries Protection Zone is an international institution on the brink of being challenged in a critical phase of being institutionalized as a Norwegian property regime. The potential disturbance comes from the zooplankton redfeed, a new and valuable resource harvestable within the zone. Though the pressures on Norway’s inspection routines in the zone are challenged at times, this article suggests that the zone as a management regime is a surprisingly robust institution still. Nevertheless, in such a critical phase it is important not to allow possible exogenous shocks to appear, and creating a separate redfeed regime for the plankton will allow the Norwegian government to bypass this possible disturbance and allow for continued solidification of the zone into an EEZ for Norway.  相似文献   

Objective classification of galaxy spectra using the information bottleneck method   总被引：1，自引：0，他引：1  

Noam Slonim  Rachel Somerville  Naftali Tishby  Ofer Lahav 《Monthly notices of the Royal Astronomical Society》2001,323(2):270-284

A new method for classification of galaxy spectra is presented, based on a recently introduced information theoretical principle, the information bottleneck . For any desired number of classes, galaxies are classified such that the information content about the spectra is maximally preserved. The result is classes of galaxies with similar spectra, where the similarity is determined via a measure of information. We apply our method to ∼6000 galaxy spectra from the ongoing 2dF redshift survey, and a mock-2dF catalogue produced by a cold dark matter (CDM) based semi-analytic model of galaxy formation. We find a good match between the mean spectra of the classes found in the data and in the models. For the mock catalogue, we find that the classes produced by our algorithm form an intuitively sensible sequence in terms of physical properties such as colour, star formation activity, morphology, and internal velocity dispersion. We also show the correlation of the classes with the projections resulting from a principal component analysis.  相似文献   

Initial Results from the Southern Edgeworth-Kuiper belt Survey     

Moody  Rachel  Schmidt  Brian  Alcock  Charles  Goldader  Jeffrey  Axelrod  Tim  Cook  Kem H.  Marshall  Stuart 《Earth, Moon, and Planets》2003,92(1-4):125-130

We present preliminary results of the analysis of the first 500 squaredegrees of the Southern Edgeworth-Kuiper belt Survey, a large sky survey whichran from January 2000 to January 2003 and comprises 2900° in total. Early testspredict that we should discover ～10 bright TNOs in our data, doubling the currentknown population.  相似文献   

Limitations of Current Approaches for Predicting Groundwater Vulnerability from PFAS Contamination in the Vadose Zone     

Matt Rovero  Diana Cutt  Rachel Griffiths  Urszula Filipowicz  Katherine Mishkin  Brad White  Sandra Goodrow  Richard T. Wilkin 《Ground Water Monitoring & Remediation》2021,41(4):62-75

Published literature for reported sorption coefficients (K_d) of eight anionic per- and polyfluoroalkyl substances (PFAS) in soil was reviewed. K_d values spanned three to five log units indicating that no single value would be appropriate for use in estimating PFAS impacts to groundwater using existing soil-water partition equations. Regression analysis was used to determine if the soil or solution parameters might be used to predict K_d values. None of the 15 experimental parameters collected could individually explain variability in reported K_d values. Significant associations between K_d and soil calcium and sodium content were found for many of the selected PFAS, suggesting that soil cation content may be critical to PFAS sorption, as previously noted in sources like Higgins and Luthy (2006), while organic carbon content was significant only at elevated levels (>5%). Unexplained discrepancies between the results from studies where PFAS were introduced to soil and desorbed in the laboratory and those that used material from PFAS-impacted sites suggest that laboratory experiments may be overlooking some aspects critical to PFAS sorption. Future studies would benefit from the development and use of standardized analytical methods to improve data quality and the establishment of soil parameters appropriate for collection to produce more complete data sets for predictive analysis.  相似文献   

Simultaneous observations of SAO and QBO in winds, temperature and ozone in the tropical middle atmosphere over Thumba (8.5��N, 77��E)     

Karanam Kishore Kumar  Debadatta Swain  Sherine Rachel John  Geetha Ramkumar 《Climate Dynamics》2011,37(9-10):1961-1973

Owing to the importance of middle atmosphere, recently, a Middle Atmospheric Dynamics (MIDAS) program was carried out during the period 2002?C2007 at Thumba (8.5°N, 77°E). The measurements under this program, involving regular radiosonde/rocket flights as well as atmospheric radars, provided long period observations of winds and temperature in the middle atmospheric region from which waves and oscillations as well as their forcing mechanisms particularly in the low-latitude middle atmosphere could be analyzed. However, a detailed analysis of the forcing mechanisms remains incomplete due to the lack of important measurements like ozone which is a significant contributor to atmospheric dynamics. Presently, profiles of ozone are available from TIMED/SABER (Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics/Sounding of the Atmosphere using Broad Emission Radiometry) satellite globally from about 15 to 100?km, over multiple years since 2002. In this regard, a comprehensive study has been carried out on ozone and its variability at Quasi Biennial Oscillation (QBO) and Semiannual Oscillation (SAO) scales using TIMED/SABER ozone observations during the MIDAS campaign period. Before using the TIMED/SABER ozone measurements, an inter-comparison has been carried out with in situ measurements of ozone obtained under the Southern Hemisphere Additional Ozonesondes (SHADOZ) campaign for the year 2007 at few stations. The inter-comparison showed very good agreement between SABER and ozonesonde derived ozone profiles. After validating the SABER observations, ozone profiles are used extensively to study the QBO and SAO along with temperature and winds in the 20?C100?km height region. It is known that the SAO in mesosphere and stratosphere are in opposite phases, but the present study for the first time reports the aspect of opposite phases in the mesosphere itself. Thus, the present work attempts to study the long-period oscillations in stratosphere and mesosphere in ozone, temperature and winds simultaneously for the first time over this latitude. These observations provided a unique opportunity to explore long-period oscillations in chemistry, dynamics and thermal structure of the middle atmosphere simultaneously.  相似文献   

Old Smokey coal fire, Floyd County, Kentucky: Estimates of gaseous emission rates     

Jennifer M.K. O'KeefeErika R. Neace  Edward W. LemleyJames C. Hower  Kevin R. HenkeGregory Copley  Rachel S. HatchAnne B. Satterwhite  Donald R. Blake 《International Journal of Coal Geology》2011,87(2):150-156

Vent emissions of the Old Smokey coal fire, Floyd County, Kentucky, were studied in May and July, 2010. Vent emissions were generally lower in July, perhaps due to a shift in the fire front, change in vent structure, or another unidentified factor. Volatile organics in the vent gasses contain dangerous levels of toxic, carcinogenic, and other hazardous compounds. Benzene ranges to nearly 400 parts per billion (volume) at one vent. Toluene exceeds 104 parts per billion (volume) at the same vent.Flux rates for CO₂ and CO range to 85,000 mg/s/m² and 89 mg/s/m², respectively, for various vents for the two measuring times. Estimates of total CO₂ emissions, possibly less than 1000 t/year, are within the range of other eastern Kentucky coal fires.  相似文献   

Second-Hand Spaces: Restructuring Retail Geographies in an Era of E-Commerce   总被引：1，自引：0，他引：1  

Brenda Parker  Rachel Weber 《Urban geography》2013,34(8):1096-1118

Are online markets replacing or remaking second-hand markets in cities? The restructuring of secondary markets in light of virtual outlets like eBay is not well understood. In this article, we describe secondary markets and their important historic, economic, cultural, and social roles in cities. The literature on e-Commerce suggests that virtual retailers compete with bricks-and-mortar stores and potentially displace them. We question whether the internet can substitute for second-hand stores, which have traditionally relied on a loyal and local customer base, personalized shopping experiences, and surprise encounters. Given the historically embedded nature of exchange, we focus on one large Mid-western city, drawing upon survey and interview data from Chicago retailers. Our exploration of supply, demand, and geographic practices reveals subtle and complex alterations in second-hand exchange, rather than a displacement of second-hand markets by eBay. We also find substantive integration, fluidity, and hybridization within and across market sectors. Rather than supplant the production of new goods, secondary markets are intertwined with and deepen primary markets, calling into question some of the presumed benefits of and meanings associated with second-hand exchange as well as the usefulness of categorical distinctions. [Key words: secondary markets, second-hand, resale, thrift, e-commerce, eBay.]  相似文献   

Arsenic Remediation Field Study Using a Sulfate Reduction and Zero‐Valent Iron PRB     

Brett Beaulieu  Rachel Elena Ramirez 《Ground Water Monitoring & Remediation》2013,33(2):85-94

Toxic and carcinogenic effects of arsenic in drinking water continue to impact people throughout the world and arsenic remains common in groundwater at cleanup sites and in areas with natural sources. Advances in groundwater remediation are needed to attain the low concentrations that are protective of human health and the environment. In this article, we present the successful use of a permeable reactive barrier (PRB) utilizing sulfate reduction coupled with zero‐valent iron (ZVI) to remediate the leading edge of a dissolved arsenic plume in a wetland area near Tacoma, Washington. A commercially available product (EHC‐M®, Adventus Americas Inc., Freeport, Illinois) that contains ZVI, organic carbon substrate, and sulfate was injected into a reducing, low‐seepage‐velocity aquifer elevated in dissolved arsenic and iron from a nearby, slag‐containing landfill. Removal effectiveness was strongly correlated with sulfate concentration, and was coincident with temporary redox potential (Eh) reductions, consistent with arsenic removal by iron sulfide precipitation. The PRB demonstrates that induced sulfate reduction and ZVI are capable of attaining a regulatory limit of 5 µg/L total arsenic, capturing of 97% of the arsenic entering the PRB, and sustaining decreased arsenic concentrations for approximately 2 years, suggesting that the technology is appropriate for consideration at other sites with similar hydrogeochemical conditions. The results indicate the importance of delivery and longevity of minimum sulfate concentrations and of maintaining sufficient dissolved organic carbon and/or microscale ZVI to precipitate FeS, a precursor phase to arsenic‐bearing pyrite that may provide a stable, long‐term sink for arsenic.  相似文献   

A soil moisture monitoring network to assess controls on runoff generation during atmospheric river events     

Edwin Sumargo  Hilary McMillan  Rachel Weihs  Carolyn J. Ellis  Anna M. Wilson  F. Martin Ralph 《水文研究》2021,35(1):e13998

Soil moisture is a key modifier of runoff generation from rainfall excess, including during extreme precipitation events associated with Atmospheric Rivers (ARs). This paper presents a new, publicly available dataset from a soil moisture monitoring network in Northern California's Russian River Basin, designed to assess soil moisture controls on runoff generation under AR conditions. The observations consist of 2-min volumetric soil moisture at 19 sites and 6 depths (5, 10, 15, 20, 50, and 100 cm), starting in summer 2017. The goals of this monitoring network are to aid the development of research applications and situational awareness tools for Forecast-Informed Reservoir Operations at Lake Mendocino. We present short analyses of these data to demonstrate their capability to characterize soil moisture responses to precipitation across sites and depths, including time series analysis, correlation analysis, and identification of soil saturation thresholds that induce runoff. Our results show strong inter-site Pearson's correlations (>0.8) at the seasonal timescale. Correlations are strong (>0.8) during events with high antecedent soil moisture and during drydown periods, and weak (<0.5) otherwise. High event runoff ratios are observed when antecedent soil moisture thresholds are exceeded, and when antecedent runoff is high. Although local heterogeneity in soil moisture can limit the utility of point source data in some hydrologic model applications, our analyses indicate three ways in which soil moisture data are valuable for model design: (1) sensors installed at 6 depths per location enable us to identify the soil depth below which evapotranspiration and saturation dynamics change, and therefore choose model soil layer depths, (2) time series analysis indicates the role of soil moisture processes in controlling runoff ratio during precipitation, which hydrologic models should replicate, and (3) spatial correlation analysis of the soil moisture fluctuations helps identify when and where distributed hydrologic modelling may be beneficial.  相似文献   

CANOPEX: A Canadian hydrometeorological watershed database          下载免费PDF全文

Richard Arsenault  Rachel Bazile  Camille Ouellet Dallaire  François Brissette 《水文研究》2016,30(15):2734-2736

Over the past few years, many international initiatives and collaborations were launched to improve and share knowledge in hydrology research. Large databases allowed finding patterns and relationships across regions and scales. This paper introduces the Canadian model parameter experiment (CANOPEX) database, which is adapted from the US MOPEX project data and methods. The CANOPEX database includes meteorological and hydrometric data as well as watershed boundaries for 698 basins. Two sets of basin‐averaged meteorological data (Maximum and minimum temperature and precipitation) are provided. The first dataset is directly taken from Environment Canada's weather stations whereas the second is extracted from the Natural Resources Canada gridded climate data product. Data are provided in MOPEX and Matlab formats. CANOPEX watersheds are well distributed over Canada, which allows investigating a variety of physiological and climatological conditions. The CANOPEX database can be used in a variety of hydrologic research projects such as climate change impact studies, model comparisons, multi‐modelling, ensemble streamflow prediction and model parameter estimation. CANOPEX could be used to generalize findings to other cold climate catchments as well as assess the robustness of research methodologies and procedures. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献