Comment on the atmospheric distribution of lead over a number of marine regions     

C.N. Hewitt  R.M. Harrison  S.J. De Mora 《Marine Chemistry》1984,15(2):189-190

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THE USE OF QUANTITATIVE METHODS IN MAJOR GEOGRAPHICAL JOURNALS, 1956–1986*     

Terry A. Slocum 《The Professional geographer》1990,42(1):84-94

Ninety mainstream quantitative methods used in 14 major geographical journals are analyzed for four selected years: 1956, 1966, 1976, and 1986. Mainstream methods are used in 53% of all articles in 1986, as opposed to 3% in 1956. Both the intensity and variety of methods used also increased, particularly in physical and techniques articles compared to human articles. Major methods that dominate the entire period include bivariate correlation and regression, multiple regression, factor analyses, and chi-square. The use of nonparametric methods is increasing, although their frequency of occurrence is still low. Spatial autocorrelation and advanced multiple regression appear to be strong newcomers to the discipline.  相似文献   

Backscatter laser velocimeter for energetic bottom boundary layers: The optical signal     

Agrawal  Y. Terry  W.  Jr. Williams  A.  III 《Oceanic Engineering, IEEE Journal of》1982,7(4):150-154

The optical signal from a dual-beam backscatter laser Doppler velocimeter designed for oceanographic usage will be described both theoretically and experimentally. The instrument was constructed to simulate, in the laboratory, the strength and behavior of the optical signal as a function of mass concentration of natural particles in water-a subject of concern in the study of high energy benthic boundary layers. It has been found that with proper design, the predominant mode of signal degradation with increasing particle loading is caused primarily by increased shot-noise due to signal attenuation alone. Secondly, the signal is observed to be in the single-scatterer mode at particle concentrations of up to 5 mg/l. Variations in observed signal-to-noise ratio will be described and compared with theoretical calculations.  相似文献   

Ecological entrepreneurship: sustainable development in local communities through quality food production and local branding     

Terry Marsden  Everard Smith 《Geoforum》2005,36(4):440-451

The paper explores the importance of specialised networks in shaping local/regional responses to the deepening crisis of conventional agriculture in the EU, as well as potentially creating a more sustainable platform for rural development. The emphasis will be on the problem-solving aspects of network creation and maintenance within a broader and not necessarily supportive competitive and regulatory environment. This involves examining, both over time and space, how networks function to shape knowledge and create a competitive willingness to innovate to achieve mutually beneficial goals. Through a process which we call ecological entrepreneurship, key actors facilitate sustainable development in the countryside by a combination of fragmentation, specialisation and quality building strategies. We empirically explore these evolutionary and spatial factors through two farming-centred networks—an organic farming network in the UK: the Graig Farm Producer Group; and a regional quality brand in the Netherlands: the Waddengroup Foundation.The analysis of these two networks is used to examine in-depth the significance and construction of the social and spatial milieu for providing the individual and collective capabilities to establish viable problem-solving responses. This raises questions of: (i) how such networks are and can be sustained over time; (ii) the extent to which there are common evolutionary pathways which reproduce and embed problem-solving network building; (iii) how different spatial relations are engendered and (iv) whether such ‘local’ projects can advance to wider counter-movements in the context of the prevailing political economy.  相似文献   

Reply to comment by D.J. Easterbrook (Quaternary Research 2003, 59 #1, 132-134) on “Determination of Cl Production Rates from the Well-Dated Deglaciation Surfaces of Whidbey and Fidalgo Islands, Washington”     

Terry W. Swanson 《Quaternary Research》2005,63(2):228-230

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Probabilistic analysis of rock slope stability and random properties of discontinuity parameters, Interstate Highway 40, Western North Carolina, USA   总被引：1，自引：0，他引：1  

Hyuck-Jin Park  Terry R. West  Ik Woo 《Engineering Geology》2005,79(3-4):230-250

Probabilistic analysis has been used as an effective tool to evaluate uncertainty so prevalent in variables governing rock slope stability. In this study a probabilistic analysis procedure and related algorithms were developed by extending the Monte Carlo simulation. The approach was used to analyze rock slope stability for Interstate Highway 40 (I-40), North Carolina, USA. This probabilistic approach consists of two parts: analysis of available geotechnical data to obtain random properties of discontinuity parameters; and probabilistic analysis of slope stability based on parameters with random properties. Random geometric and strength parameters for discontinuities were derived from field measurements and analysis using the statistical inference method or obtained from experience and engineering judgment of parameters. Specifically, this study shows that a certain amount of experience and engineering judgment can be utilized to determine random properties of discontinuity parameters. Probabilistic stability analysis is accomplished using statistical parameters and probability density functions for each discontinuity parameter. Then, the two requisite conditions, kinematic and kinetic instability for evaluating rock slope stability, are determined and evaluated separately, and subsequently the two probabilities are combined to provide an overall stability measure. Following the probabilistic analysis to account for variation in parameters, results of the probabilistic analyses were compared to those of a deterministic analysis, illustrating deficiencies in the latter procedure. Two geometries for the cut slopes on I-40 were evaluated, the original 75° slope and the 50° slope which has developed over the past 40 years of weathering.  相似文献   

The Development of Seasonal and Inter-Annual Climate Forecasting     

Mike Harrison 《Climatic change》2005,70(1-2):201-220

A review of the development and status of seasonal to inter-annual climate forecasting up until 2001 is presented covering not only the successes but also identifying some of the major challenges remaining. Included is discussion on the history of the enterprise; the scientific basis of modern seasonal to inter-annual prediction and its background of predictability theory; the current status of predictions and the measurement of their skill; the experiences and consequences of the 1997–1998 El Niño event; approaches to linking forecasts with applications; and a view to the future.  相似文献   

2007: International Heliophysical Year   总被引：2，自引：0，他引：2  

Prof.  Richard Harrison  Dr  y Breen  Dr  Barbara Bromage  Dr  Joe Davila 《Astronomy& Geophysics》2005,46(3):3.27-3.30

The International Heliophysical Year is an international programme of global research to understand the external drivers of the space environment and climate, continuing the tradition of previous International Years. It is introduced here by Richard Harrison, Andy Breen, Barbara Bromage and Joe Davila.  相似文献   

A long-term Arctic snow depth record from Abisko, northern Sweden, 1913–2004     

Jack Kohler  Ola Brandt  Margareta Johansson  Terry Callaghan 《Polar research》2006,25(2):91-113

A newly digitized record of snow depth from the Abisko Scientific Research Station in northern Sweden covers the period 1913-present. Mean snow depths were taken from paper records of measurements made on a profile comprising 10 permanent stakes. This long-term record yields snow depths consistent with two other shorter term Abisko records: measurements made at another 10-stake profile (1974-present) and at a single stake (1956-present). The measurement interval is variable, ranging from daily to monthly, and there are no data for about half of the winter months in the period 1930-1956. To fill the gaps, we use a simple snowpack model driven by concurrent temperature and precipitation measurements at Abisko. Model snow depths are similar to observed; differences between the two records are comparable to those between profile and single stake measurements. For both model and observed snow depth records, the most statistically significant trend is in winter mean snow depths, amounting to an increase of about 2 cm or 5 % of the mean per decade over the whole measurement period, and 10% per decade since the 1930-40s, but all seasonal means of snow depth show positive trends on the longest timescales. However, the start, end, and length of the snow season do not show any statistically significant long-term trends. Finally, the relation between the Arctic Oscillation index and Abisko temperature, precipitation and snow depth is positive and highly significant, with the best correlations for winter.  相似文献   

Recent rapid salinity rise in three East Antarctic lakes   总被引：1，自引：0，他引：1  

Donna Roberts  Dominic A. Hodgson  Andrew McMinn  Elie Verleyen  Bruce Terry  Christine Corbett  Wim Vyverman 《Journal of Paleolimnology》2006,36(4):385-406

Research in East Antarctica has shown several recent environmental changes that may be linked to human impacts on climate. In order to detect the influence and context of these changes on coastal aquatic ecosystems we examined lake sediment cores from three lakes in the Windmill Islands, East Antarctica; Beall Lake, Holl Lake and ȁ8Lake Mȁ9. Cores were sectioned at␣2.5 mm intervals. Their diatom species composition was examined to detect changes in lake salinity using a diatom-salinity transfer function, and their algal pigment content was examined to detect photoautotrophic community responses to environmental change. Results showed that Holl Lake originated in a depression exposed by Holocene recession of the continental ice sheet and that Beall Lake and Lake M originated as isolated marine basins formed by changes in relative sea level. A general late Holocene trend of declining lake salinity was evident in all three lakes, interrupted by one short-term high salinity event in Beall Lake. This is consistent with a long-term positive moisture balance. This general decline in salinity has been followed by a remarkable recent rapid increase in salinity in all three lakes in the last few decades. We speculate that this rapid increase in salinity might be linked to changes taking place in the region including feedbacks resulting from decreasing sea ice extent as recorded in the nearby Law Dome ice core, and positive feedbacks in the catchments whereby reduced snow cover has led to decreased albedo, which in turn has caused increased evaporation and sublimation. Collectively these changes have shifted the lakes across a threshold from positive to negative moisture balance. A minor, but not rapid shift in the abundance of diatom pigments relative to pigments from green algae and cyanobacteria was also detected suggesting that some changes in photoautotrophic community composition have occurred. Measurements of modern nutrient levels are also higher than would be expected in Beall Lake and Holl Lake, given the extremely low sediment accumulation rates. This may be associated with a c. 300% increase in the population of Adélie penguins in the Windmill Islands recorded since the 1950s, or may a first signs of a rapid increase in catchment development and associated lake productivity as experienced in Antarctic and Arctic lakes subject to recent rapid regional warming. The most marked feature of the records is the rapid increase in salinity in all three lakes in␣the last few decades, which has occurred in lakes both with and without resident penguin populations.Dominic A. Hodgson and Donna Roberts contributed equally to this work  相似文献