Airborne lidar measurements of aerosol spatial distribution and optical properties over the Atlantic Ocean during a European pollution outbreak of ACE‐2     

Cyrille Flamant  Jacques Pelon  Patrick Chazette  Vincent Trouillet  Patricia K. Quinn  Robert Frouin  Didier Bruneau  Jean François Leon  Timothy S. Bates  James Johnson  John Livingston 《Tellus. Series B, Chemical and physical meteorology》2000,52(2):662-677

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A new early Holocene cryptotephra from northwest Scotland     

Patricia H. Ranner  Judy R. M. Allen  Brian Huntley 《第四纪科学杂志》2005,20(3):201-208

Clarification of the temporal relationships amongst records of environmental change is dependent on accurate timescales. Event markers such as tephra layers are extremely important for constraining chronologies and providing tie points. In this report we present evidence of a previously unknown early Holocene Icelandic cryptotephra from a lake in northern Scotland—the ‘An Druim Tephra’. The calibrated radiocarbon age of 9560 cal. yr BP for this new cryptotephra makes it an important addition to the suite of cryptotephras now recorded from the last glacial termination and early Holocene in northwest Europe. In addition we report evidence in support of a ‘Younger Borrobol Tephra’ from Lateglacial sediments of Allerød age. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Aerosol physical properties and processes in the lower marine boundary layer: a comparison of shipboard sub‐micron data from ACE‐1 and ACE‐2     

Timothy S. Bates  Patricia K. Quinn  David S. Covert  Derek J. Coffman  James E. Johnson  Alfred Wiedensohler 《Tellus. Series B, Chemical and physical meteorology》2000,52(2):258-272

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GIS Investigation of the relationship of sex and season on the population distribution of common bottlenose dolphins (Tursiops truncatus) in Charleston,South Carolina     

Hannah Bouchillon  Norman S. Levine  Patricia A. Fair 《International journal of geographical information science》2020,34(8):1552-1566

ABSTRACT

The Charleston Estuarine System Stock (CESS) of common bottlenose dolphins (Tursiops truncatus) has been the focus of population monitoring for the past 20 years. Photo-id studies have determined abundance and survival estimates for this population, which exhibits high site fidelity in this area. However, fine-scale distribution, utilization patterns, and the driving forces behind these patterns are lacking. Using historical photo-id data and a novel application of geographic information system (GIS) analysis, the present study identified core use areas within Charleston Harbor, as well as patterns specific to sexes and seasons. Photo-id data of 319 dolphins sighted 11 times or more during 2004–2009 were analyzed. Heat maps were developed to examine spatial distributions using kernel density estimates (KDE) and were compared between sexes and seasons. Multiple high-density core use areas were identified for this population, with the most noteworthy near the mouth of the harbor toward the Atlantic Ocean. Fine-scale distribution varied across sexes, as well as seasons. Some areas were identified as more specifically inhabited by one sex, while other areas overlapped between sexes. Females were more tightly concentrated within their distribution while males were more dispersed. Although population distribution varied across seasons, sex distributions remained.  相似文献   

Induction of DNA strand breaks in the mussel (Mytilus trossulus) and clam (Protothaca staminea) following chronic field exposure to polycyclic aromatic hydrocarbons from the Exxon Valdez spill   总被引：1，自引：0，他引：1  

Thomas RE  Lindeberg M  Harris PM  Rice SD 《Marine pollution bulletin》2007,54(6):726-732

In 2002, 13 years after the Exxon Valdez spill, mussels and clams were examined for lingering oil exposure and damage. Known oil patches were sampled at four locations, and compared to nearby reference areas (same bay), and were also compared to "hot reference" sites to verify the methods used (Cordova harbor and fresh diesel spill at Port Chalmers). Passive samplers deployed for a month at the sites, along with tissue samples, confirmed that the oiled sites were oiled (fingerprinting back to Exxon Valdez oil) and that reference sites were clean. The highest PAH loads were detected in sub-surface interstitial waters at oiled sites. Exposure at the surface was generally low level, and probably intermittent. DNA damage was assessed in blood cells using sensitive comet analyses. DNA strand breakage was detected in both mussels and clams, with the highest level of damage detected at "hot reference" sites of Cordova harbor and Port Chalmers. Bioavailability and DNA damage at the oiled sties was low, indicating there has been substantial progress in recovery from the spill 13 years before, yet low level bioavailability and damage were still detectable.  相似文献   

An Evaluation of Soil-Gas Surveying for H₂S for Locating Subsurface Hydrocarbon Contamination     

Gary A. Robbins  Brian E. McAninch  Francis M. Gavas  Patricia M. Ellis 《Ground Water Monitoring & Remediation》1995,15(1):124-132

A soil-gas survey was conducted at a gasoline service station and a former fire training facility to determine if surveying for hydrogen sulfide could be useful in locating nonaqueous phase hydrocarbon fuel in the subsurface. Relative; to total organic vapor, oxygen, and carbon dioxide distributions, detectable hydrogen sulfide concentrations were much more restricted to the suspected source vicinity at both sites. Appreciable levels of soil-gas hydrogen sulfide. up to 600 Vppb. were observed in areas characterized by anaerobic or microaerophilic conditions having bulk oxygen levels below 4 percent. Based on the hydrogen sulfide distribution, nonaqueous phase hydrocarbon fuel was located at each site. These results suggest that soil-gas surveying for hydrogen sulfide may help locale mobile or residual gasoline and other nonaqueous phase hydrocarbons in the subsurface.  相似文献   

Effect of the selective feeding ofGalaxias maculatus (Salmoniformes,Galaxiidae) on zooplankton of a South Andes lake     

Beatriz E. Modenutti  Esteban G. Balseiro  Patricia M. Cervellini 《Aquatic Sciences - Research Across Boundaries》1993,55(1):65-75

The effect of larval and juvenile predation ofGalaxias maculatus on a natural small-sized zooplankton was studied in a South Andes lake. Field data of zooplankton density and composition were combined with fish gut content analysis during a spring-summer season. Results showed thatGalaxias early stages ingested mostly planktonic preys. A shift was observed in prey electivity: larvae preferred copepod nauplii whereas juveniles preferred cladocerans. Larval predation provokes the failure of the summer cohort of the calanoid copepodBoeckella gracilipes. The effect of juveniles is more undefined, but seems to prevent the reappearance ofCeriodaphnia in the summer plankton.  相似文献   

How the very poor survive -the impact of hyper-inflationary crisis on low-income urban households in Buenos Aires/Argentina     

Patricia Aguirre 《GeoJournal》1994,34(3):295-304

This paper is based on an anthropological research with a longitudinal type of design on the Domestic Consumer Strategies of 30 extremely poor families with undernourished children, living in the Greater Metropolitan Area of Buenos Aires, Argentina. They are analysed on the basis of food intake, as this is one aspect of survival strategies that can be measured.Domestic Consumer Strategies analyse phenomena such as government policy regarding food programmes, wages and prices at the macrosocial level, and microsocial phenomena like the selective distribution of food in the home by sex and age.  相似文献   

An annual fossil record of production,planktivory and piscivory during whole-lake manipulations     

Peter R. Leavitt  Patricia R. Sanford  Stephen R. Carpenter  James F. Kitchell 《Journal of Paleolimnology》1994,11(2):133-149

Annual and subannual paleolimnological records of pigments and zooplankton were used to analyze three whole-lake manipulations. The relative abundance of cladoceran remains in recent seasonal laminae was significantly correlated with the relative abundance of species in the plankton (r ²=0.59,P<0.001). Comparison of food-web structure after piscivore introduction showed that there are multiple outcomes of predation and that final food-web structure depended on the strength of interaction between piscivorous and planktivorous fish. Intense predation on cyprinids (Phoxinus eos, P. neogaeus, Umbra limi) by largemouth bass (Micropterus salmoides) allowed large herbivores (Daphnia pulex) and invertebrate predators (Chaoborus punctipennis) to dominate. Analysis of fossil invertebrate morphology suggested that small grazers (Bosmina longirostris, Diaphanosoma birgei) were eliminated by invertebrate predators. Under moderate predation by rainbow trout (Oncorhynchus mykiss), cyprinids remained, only intermediate-size herbivores (D. rosea) increased in abundance, andBosmina persisted. In contrast to food-web manipulations, increased algal abundance resulting from watershed disturbance (road construction) did not alter the species composition or size-structure of fossil Cladocera.  相似文献   

The effects of changing solar angles,cloud regimes,and air temperatures on the temperatures of contrasting surfaces     

Werner H. Terjung  Patricia A. O'Rourke 《Boundary-Layer Meteorology》1982,24(3):269-279

A steady-state energy budget and a solar radiation-cloud attenuation model have been linked. This has permitted a systematic examination of the changing relative surface temperatures and differences between surface and air temperatures as functions of varying solar altitudes, selected cloud types, cloud covers, and air temperatures. This analysis was performed for two contrasting surfaces: barren and grassy. The results are presented in a series of three-dimensional graphs. The grassy landscape reacted more conservatively to changing solar altitudes (for all cloud types and amounts) compared with the barren surface. The results are assumed to encompass most of the possible extremes encountered in real landscapes exposed to similar changes in solar angle, air temperatures, and cloud regimes.Dr. O'Rourke is currently a Post-Doctoral Scholar at UCLA.  相似文献