Multidecadal simulation of coastal fog with a regional climate model     

Travis A. O’Brien  Lisa C. Sloan  Patrick Y. Chuang  Ian C. Faloona  James A. Johnstone 《Climate Dynamics》2013,40(11-12):2801-2812

In order to model stratocumulus clouds and coastal fog, we have coupled the University of Washington boundary layer model to the regional climate model, RegCM (RegCM-UW). By comparing fog occurrences observed at various coastal airports in the western United States, we show that RegCM-UW has success at modeling the spatial and temporal (diurnal, seasonal, and interannual) climatology of northern California coastal fog. The quality of the modeled fog estimate depends on whether coast-adjacent ocean or land grid cells are used; for the model runs shown here, the oceanic grid cells seem to be most appropriate. The interannual variability of oceanic northern California summertime fog, from a multi-decadal simulation, has a high and statistically significant correlation with the observed interannual variability (r = 0.72), which indicates that RegCM-UW is capable of investigating the response of fog to long-term climatological forcing. While RegCM-UW has a number of aspects that would benefit from further investigation and development, RegCM-UW is a new tool for investigating the climatology of coastal fog and the physical processes that govern it. We expect that with appropriate physical parameterizations and moderate horizontal resolution, other climate models should be capable of simulating coastal fog. The source code for RegCM-UW is publicly available, under the GNU license, through the International Centre for Theoretical Physics.  相似文献   

Understanding carbon trading: Effects of delegating CO2 responsibility on organizations’ trading behaviour     

Juan Miguel Rodriguez Lopez  Anita Engels  Lisa Knoll 《Climate Policy》2013,13(3):346-360

The establishment of a carbon market assumes that there is an effective means of transforming price information into technical carbon reduction measures. However, empirical evidence reveals that the links between price information and carbon management strategies are far from obvious. To understand how delegating CO₂ responsibility affects CO₂ trading behaviour, this article proposes a neo-institutionalist approach to answering the question of why companies became sellers, buyers or a combination of both during phase I of the European Emissions Trading Scheme (EU ETS). Original data from a survey on companies that participated in this scheme were collected and analysed. It was assumed that the trading scheme offered two ways to delegate decisions regarding emissions trading: decoupling from technical knowledge and financialization (i.e. delegating to financial departments) or coupling using technicalization (i.e. delegating to manufacturing departments). The results support the hypothesis that a company that adopts a decoupling strategy is more likely to buy certificates to fulfil their emissions targets. Adopting a coupling strategy indicates that a company is more likely to become a seller, all else equal. Professional identity is the theoretical basis for this relationship. Delegating carbon management to different departments represents either a stronger coupling or a stronger decoupling from core technological processes.

Policy relevance

The transaction data from phase I of the EU ETS open new questions and possibilities regarding the reasons that drive selling and buying in companies. It is important to look not only at the traditional sources of transaction costs, but rather also at the reasons for these tensions. One important source is the professional education of the people in charge of the EU ETS. Tailored information that directly addresses the different professional backgrounds of managers working in both financial departments and more technical departments might help to lower these types of transaction costs. In today's context, important emitter countries, such as China and Korea, have launched their own emissions markets, copying many aspects of the EU ETS. For the positive development of these markets and as a way of establishing a global emissions market, these new schemes should learn from the EU ETS experience.  相似文献   

Threshold of tolerance model: strategy for international travel     

Deborah Meyer  Lisa Robyn Barnes  Anton Kriz 《GeoJournal》2014,79(5):557-563

The purpose of this research is to investigate what factors influence the management of International Business Air Travel (IBAT). The researchers interviewed 34 business travellers, travel organisers and executives involved in IBAT from ten organisations in differing industries, in Australia. It was found that there are a multitude of factors influencing IBAT management, including professionalism and job satisfaction of travellers and the achievement of organisational goals such as carrying out successful international ventures or operating effectively in international markets. From the findings a strategic model was developed called the Threshold of Tolerance Model—which illustrates the potential point where both organisational goals are most likely to be met and where IBAT is most likely to be well managed for both travellers and organisations.  相似文献   

Three-dimensional hydrofacies assemblages in ice-contact/proximal sediments forming a heterogeneous ‘hybrid’ hydrostratigraphic unit in central Illinois,USA     

Lisa A. Atkinson  Martin Ross  Andrew J. Stumpf 《Hydrogeology Journal》2014,22(7):1605-1624

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A literature review of Algerian salt lakes: values,threats and implications     

Fatma Demnati  Boujéma Samraoui  Farid Allache  Alain Sandoz  Lisa Ernoul 《Environmental Earth Sciences》2017,76(3):127

Chotts are salt lakes located in the arid regions of Northern Africa. These unique wetlands are recognized for their role in the migration and breeding of waterbirds and economic values generated from mineral extraction, agriculture and tourist activities. Despite their importance for flora and fauna biodiversity, they continue to face important threats due to human activities. This article consolidates a literature review of Algerian chotts from global to local importance. An in-depth view demonstrates the changes in land use of two large chotts in the southeastern region of Algeria: Chotts Merouane and Melghir. Land use images highlight a net expansion of agricultural lands, a decrease in grazing area around the lakes and a decrease of salt lake surface area. The local focus highlights the threats and changes of Algerian and Northern African chotts and proposes some perspectives for the future.  相似文献   

The Big Issue:¹ empowering homeless women through academic research?     

Lisa Doyle 《Area》1999,31(3):239-246

Summary This paper discusses academic research as a means of empowerment for people in marginalized groups, using the example of homeless women. Issues connected to the position of the researcher in relation to both the agencies dealing with homeless people and the homeless women themselves are discussed. Many agencies have underlying ideologies and overt practices that reinforce hierarchical relations and certain gendered expectations. The paper considers the difficulties this creates when working with and presenting findings to agencies whose principles are in conflict with one's own, and also discusses the social relations of conducting empowering doctoral research.  相似文献   

Stable Sulfur Isotopic Evidence for Historical Changes of Sulfur Cycling in Estuarine Sediments from Northern Florida     

Volker Brüchert  Lisa M. Pratt 《Aquatic Geochemistry》1999,5(3):249-268

Data on abundance and isotopic composition of porewater and sedimentary sulfur species are reported for relatively uncontaminated and highly contaminated fine-grained anoxic sediments of St. Andrew Bay, Florida. A strong contrast in amount and composition of sedimentary organic matter at the two sites allows a comparative study of the historical effects of increased organic loading on sulfur cycling and sulfur isotopic fractionation. In the contaminated sediments, an increase in organic loading caused increased sedimentary carbon/sulfur ratios and resulted in higher rates of bacterial sulfate reduction, but a lower efficiency of sulfide oxidation. These differences are well reflected in the isotopic composition of dissolved sulfate, sulfide, and sedimentary pyrite. Concentration and isotopic profiles of dissolved sulfate, organic carbon, and total sulfur suggest that the anaerobic decomposition of organic matter is most active in the upper 8cm but proceeds at very slow rates below this depth. The rapid formation of more than 90% of pyrite in the uppermost 2 cm which corresponds to about 3 years of sediment deposition allows the use of pyrite isotopic composition for tracing changing diagenetic conditions. Sediment profiles of the sulfur isotopic composition of pyrite reflect present-day higher rates of bacterial sulfate reduction and lower rates of sulfide oxidation, and record a profound change in the diagenetic cycling of sulfur in the contaminated sediments coincident with urban and industrial development of the St. Andrew Bay area.  相似文献   

Sensitivity of the tropical Pacific Ocean to precipitation-induced freshwater flux     

S. Yang  K.-M. Lau  P. S. Schopf 《Climate Dynamics》1999,15(10):737-750

We have performed experiments using an ocean model to study the sensitivity of tropical Pacific Ocean to variations in precipitation induced freshwater fluxes. Variations in these fluxes arise from natural causes on all time scales. In addition, estimates of these fluxes are uncertain because of differences among measurement techniques. The model used is a quasi-isopycnal model, covering the Pacific from 40?°S to 40?°N. The surface forcing is constructed from observed wind stress, evaporation, precipitation, and sea surface temperature (SST) fields. The heat flux is produced with an iterative technique so as to maintain the model close to the observed climatology, but with only a weak damping to that climatology. Climatological estimates of evaporation are combined with various estimates of precipitation to determine the net surface freshwater flux. Results indicate that increased freshwater input decreases salinity as expected, but increases temperatures in the upper ocean. Using the freshwater flux estimated from the Microwave Sounding Unit leads to a warming of up to 0.6?°C in the western Pacific over?a case with zero net freshwater flux. SST is sensitive to the discrepancies among different precipitation observations, with root-mean-square differences in SST on the order of 0.2–0.3?°C. The change in SST is more pronounced in the eastern Pacific, with difference of over 1?°C found among the various precipitation products. Interannual variation in precipitation during El Niño events leads to increased warming. During the winter of 1982–83, freshwater flux accounts for about 0.4?°C (approximately 10–15% of the maximum warming) of the surface warming in the central-eastern Pacific. Thus, the error of SST caused by the discrepancies in precipitation products is more than half of the SST anomaly produced by the interannual variability of observed precipitation. Further experiments, in which freshwater flux anomalies are imposed in the western, central, and eastern Pacific, show that the influence of net freshwater flux is also spatially dependent. The imposition of freshwater flux in the far western Pacific leads to a trapping of salinity anomalies to the surface layers near the equator. An identical flux imposed in the central Pacific produces deeper and off-equatorial salinity anomalies. The contrast between these two simulations is consistent with other simulations of the western Pacific barrier layer formation.  相似文献   

Archaeological site distribution by geomorphic setting in the southern lower Cuyahoga River Valley,northeastern Ohio: Initial observations from a GIS database     

Andrew Bauer  Kathleen Nicoll  Lisa Park  Timothy Matney 《Geoarchaeology》2004,19(8):711-729

In this study, we compiled unpublished archival documentation of archaeological site locations from the southern part of the Cuyahoga River Valley in northeastern Ohio, USA, registered at the State of Ohio Historic Preservation Office into a Geographic Information Systems (GIS) database. Using digitized soil shapefiles to generate a geomorphic data layer, we assessed the spatial and temporal distribution of 79 known archaeological sites by landform association. This digital compilation indicates that Woodland period, Late Prehistoric, and Historic sites occur in most geomorphic settings along the river valley. In contrast, Paleoindian and Archaic sites only occur on Wisconsinan cut terraces and in upland interfluve settings, indicating that most of these documented sites are in primary contexts and have not been reworked. We discuss the distribution of archaeological sites in the study region as a function of various factors, including cultural activities, taphonomic processes, landform development, and the nature and extent of the original archaeological surveys. Observed spatial patterns of known sites clearly reflect local geomorphological controls; artifactual contexts from the earlier prehistoric periods are underrepresented in the database. We conclude that additional site surveys, as well as the excavation and documentation of new sites in this part of Ohio, are required to understand local prehistoric economies and to ascertain patterns of culturally mediated land use. © 2004 Wiley Periodicals, Inc.  相似文献   

Integrating structure-from-motion photogrammetry into rock weathering field methodologies     

Lisa Mol  Lucy Clarke 《地球表面变化过程与地形》2019,44(13):2671-2684

Despite recent rapid advances in the field of structure-from-motion (SfM) photogrammetry, the use of high-resolution data to investigate small-scale processes is a relatively underdeveloped field. In particular, rock weathering is rarely investigated using this suite of techniques. This research uses a combination of traditional non-destructive rock weathering measurement techniques (rock surface hardness) and SfM to map deterioration and loss of cohesion of the surface using three-dimensional data. The results are used to interpret weathering behaviour across two different lithologies present on the site, namely shale and limestone. This new approach is tested on seven sites in Longyearbyen, Svalbard, where active weathering of a rock surface was measured after 13 years of exposure to extreme temperature regimes and snow cover. The surface loss was quantified with SfM and combined with rock surface hardness measurement distributions extrapolated in geographic information system (GIS). The combined results are used here to quantify the difference in response of both lithologies to these extreme temperatures. This research demonstrates the potential for further integration of SfM in rock weathering research and other small-scale geomorphological investigations, in particular in difficult field conditions where portability of field equipment is paramount. © 2019 John Wiley & Sons, Ltd. © 2019 John Wiley & Sons, Ltd.  相似文献