Beyond the Metropolis: Urban Geography as if Small Cities Mattered     

Ola Johansson 《The Professional geographer》2013,65(3):430-432

In-car satellite navigation systems (SatNavs) are among the first products based on geographic information systems to have widespread fashionable appeal. In the United Kingdom, portable versions that are easily installed on the dashboard or front windshield have become a popular vehicle accessory. As prices have fallen, demand has increased over the last few years to the point that SatNavs might soon achieve the ubiquity of in-car entertainment systems. The rise of popularity of SatNavs, however, has also brought with it increased vulnerability to vehicle crime. Our analysis for the London borough of Newham shows a threefold increase in SatNav theft that occurred from 2005–2006 to 2006–2007. This is not limited to SatNavs being on display, but criminals also looking for the telltale signs of suction marks on the windshield indicating that a portable SatNav might be in the glove compartment or trunk of the car. A geographical analysis of these crime data is presented. Whereas the geo-engineering has focused on improving real-time visualization of position and articulation of navigational instructions, the product engineering as a portable accessory has insufficiently addressed the social implications of vulnerability in a high-crime society, the consequence being a focused acquisitive crime wave.  相似文献   

Making journal articles ‘live’: turning academic writing into scientific dialog     

Ola Ahlqvist  Francis Harvey  Hyowon Ban  Wei Chen  Shaun Fontanella  Meng Guo  Nisheet Singh 《GeoJournal》2013,78(1):61-68

Web 2.0 services and social networking offer possibilities to transform academic publishing to facilitate scientific dialogue. We present ‘The Live Paper’ in this editorial as a concept to consider how to leverage existing web technologies to produce rich, omnidirectional, and interactive narratives on research. Following the format of a traditional research report we describe and discuss how to enrich research reports utilizing various types of analytical tools, data, and web services in a published paper embedded in evolving scientific discourse. We also consider how the live papers would influence the practice, culture, and economy of academic research. We conclude that geospatial researchers have an opportunity to lead this development towards richer and more open ways of communicating our findings. The technology and infrastructure to do so exist today, but several barriers remain.  相似文献   

Outlier Problem in Evaluating Similarity Functions in the Stable Atmospheric Boundary Layer   总被引：1，自引：1，他引：0  

Andrey A. Grachev  Edgar L. Andreas  Christopher W. Fairall  Peter S. Guest  P. Ola G. Persson 《Boundary-Layer Meteorology》2012,144(2):137-155

The gradient-based similarity approach removes turbulent fluxes as governing parameters and replaces them with vertical gradients of mean wind speed and potential temperature. As a result, the gradient Richardson number, Ri, appears as a stability parameter instead of the Monin–Obukhov stability parameter z/L (L is the Obukhov length). The gradient-based scaling is more appropriate for moderate and very stable conditions when the gradients are large and their errors are relatively small whereas z/L becomes ambiguous in these conditions because turbulent fluxes are small. However, the gradient-based formulation is faced with a problem related to the influence of Ri outliers: outliers with high values of Ri can exist in conditions that are really near-neutral. These outliers are mapped into the very stable range in plots in which Ri is the independent variable and may lead to spurious dependencies for bin-averaged data (spurious bin-averaging). This effect is quite large for functions that are steep for the gradient-based scaling. The present study uses the Surface Heat Budget of the Arctic Ocean (SHEBA) data to examine the problem and proposes two methods, conditional analysis and independent binning, to limit the influence of outliers on bin-averaging. A disadvantage of the conditional analysis is associated with eliminating outliers based on criteria that could be considered as subjective. The independent bin-averaging method does not have this disadvantage, but the scatter of the bin-averaged points is higher than for the conditional analysis, rendering data analysis and interpretation difficult.  相似文献   

Ion equilibrium between montmorillonite interlayer space and an external solution—Consequences for diffusional transport   总被引：1，自引：0，他引：1  

Martin Birgersson  Ola Karnland 《Geochimica et cosmochimica acta》2009,73(7):1908-1923

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Turbulent measurements in the stable atmospheric boundary layer during SHEBA: ten years after   总被引：4，自引：0，他引：4  

Andrey A. Grachev  Edgar L. Andreas  Christopher W. Fairall  Peter S. Guest  P. Ola G. Persson 《Acta Geophysica》2008,56(1):142-166

This paper surveys results of the comprehensive turbulent measurements in the stable boundary layer (SBL) made over the Arctic pack ice during the Surface Heat Budget of the Arctic Ocean experiment (SHEBA) in the Beaufort Gyre from October 1997 through September 1998. Turbulent fluxes and mean meteorological data were continuously measured and reported hourly at five levels on a 20-m main SHEBA tower. Eleven months of measurements during SHEBA cover a wide range of stability conditions, from the weakly unstable regime to very stable stratification, and allow studying the SBL in detail. A brief overview of the SBL regimes, the flux-profile relationships, the turbulent Prandtl number, and other parameters obtained during SHEBA is given. The traditional Monin—Obukhov approach, z-less scaling, and gradient-based scaling are evaluated and discussed based on the data from SHEBA.  相似文献   

Population increase impacts the climate,using the sensitive Arctic as an example          下载免费PDF全文

Ola M. Johannessen  Elena V. Shalina 《大气和海洋科学快报》2022,15(2):100192

The global population during the last 100 years has increased from 2 to 7.7 billion, causing an increase in greenhouse gases in the atmosphere. In order to see how population increase is directly related to physical variables of the climate, this Perspective article places observations and scenarios of climate change into context and puts forth a statistical modeling study on how the sensitive Arctic climate responds to the increasing population. The relationships between population, Arctic sea-ice extent (SIE), and surface air temperature (SAT) are very strong, with the increasing population explaining 96% of the decreasing SIE and about 80% of the increasing SAT in the Arctic. Our projection for the SIE using the population as a “proxy predictor” for a projected population of 10 billion people on the Earth in 2100, yields a SIE of 9.30 and 8.21 million km² for a linear and squared relationship, respectively, indicating no “tipping point” for the annual ice extent in this century. This adds another dimension to climate understanding for the public at large using population as a proxy variable, instead of the more abstract CO₂ parameter. This also indicates that it is important to attempt to limit the ongoing increase in population, which is the main cause of the greenhouse gas emissions, in addition to reducing per capita emissions by an exponential increase in implementing renewable energy, a formidable challenge in this century.  相似文献   

Preface          下载免费PDF全文

Hui-Jun Wang  Ola M.Johannessen 《大气和海洋科学快报》2018,(2)

正Special Issue to Commemorate the 10th Anniversary of Atmospheric and Oceanic Science Letters First published in late 2008 and currently in Volume 11(2018),Atmospheric and Oceanic Science Letters(AOSL)is unique in providing a rapid communication channel between academic communities concerned with the interdisciplinary research areas of atmospheric science and physical oceanography.This approach allows the journal to cover such critical issues as climate change,the cryosphere,water resources,  相似文献   

Climate change in the North- past, present and future     

Joern Thiede Ola M. Johannessen 《《幕》》2008,31(1):163-167

The Nordic countries have produced famous polar explorers and researchers who have generated climate research schools at a variety of locations. The dependence of these countries with respect to the lifelihood of their societies, of their use of lands and seas, the exploitation of marine living and non-living resources have made climate research an eminent topic, and many outstanding discoveries of longand short-term climate change have been made for the first time in Scandinavia. These include early contributions to our understanding of the geological effects of continent-wide glaciations during the ice ages, the complex postglacial history of the Baltic Sea and the varved sediment sequences preserved from lakes with an extraordinary seasonality in their sediment input, as well as the detailed records of temperature, ice texture and impurities and greenhouse gas variations of the last Glacial and of the Holocene preserved in the ice cores from Greenland. Iceland with its volcanic sequences and intercalated sediment layers not only preserved the history of this subaerial segment of the mid-Atlantic Ridge, but also easily datable paleoclimate records. The fate of the Vikings, who settled during the Medieval climate optimum on Iceland and later on Greenland and who lost their habitat on Greenland at the beginning of the Little Ice Age, illustrates vividly the climate-dependent subsistence of the indigenous and non-indigenous Scandinavian populations. Modern Scandinavian climate research institutions also include sophisticated modelling groups.  相似文献   

Benthic organic carbon flux and oxygen penetration reflect different plankton provinces in the Southern Ocean     

Oliver Sachs  Eberhard J. Sauter  Michael Schlüter  Michiel M. Rutgers van der Loeff  Kerstin Jerosch  Ola Holby 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(8):1319-1335

For the investigation of organic carbon fluxes reaching the seafloor, oxygen microprofiles were measured at 145 sites in different sub-regions of the Southern Ocean. At 11 sites, an in situ oxygen microprofiler was deployed for the measurement of oxygen profiles and the calculation of organic carbon fluxes. At four sites, both in situ and ex situ data were determined for high latitudes. Based on this data set as well as on previous published data, a relationship was established for the estimation of fluxes derived by ex situ measured O₂ profiles. The fluxes of labile organic matter range from 0.5 to 37.1 mg C m^?2 d^?1. The high values determined by in situ measurements were observed in the Polar Front region (water depth of more than 4290 m) and are comparable to organic matter fluxes observed for high-productivity, upwelling areas like off West Africa. The oxygen penetration depth, which reflects the long-term organic matter flux to the sediment, was correlated with assemblages of key diatom species. In the Scotia Sea (～3000 m water depth), oxygen penetration depths of less than 15 cm were observed, indicating high benthic organic carbon fluxes. In contrast, the oxic zone extends down to several decimeters in abyssal sediments of the Weddell Sea and the southeastern South Atlantic. The regional pattern of organic carbon fluxes derived from microsensor data suggests that episodic and seasonal sedimentation pulses are important for the carbon supply to the seafloor of the deep Southern Ocean.  相似文献   

PCB contamination from sampling equipment and packaging     

Malin Andersson  Rolf Tore Ottesen  Morten Jartun  Ola Eggen  Ann-Christine Enqvist 《Applied Geochemistry》2012

Work reported in this paper suggests that there are cases of contamination of soil and water samples by polychlorinated biphenyls (PCB) from paper and plastic packaging. Soil samples, which have been stored in paper bags for more than 20 years, share a similar congener distribution as the bags. Analyses showed a predominance of light congeners. PCB-analyses of water also indicate that water samples could be contaminated by plastic packaging. All analytical results of solid material packaging, as well as soil stored in the packaging, show a high relative amount of light weight PCB congeners. The paper bags that were analysed are made of strong paper and very popular among geochemists because of their watertight quality. These paper bags were manufactured more than 20 years ago. The plastic packaging that was analysed was produced in 1997 and 2008. The analyses of plastic and paper show that the raw material that has been used in the production at different times contains a wide concentration range of PCB. Re-sealable plastic bags, which contained the highest levels of PCB of the plastic material, are used by researchers world-wide as sampling bags for soils and sediments. This paper raises an important issue that packaging may potentially contaminate the samples that they hold.  相似文献