Enhancing the relevance of Shared Socioeconomic Pathways for climate change impacts,adaptation and vulnerability research

This paper discusses the role and relevance of the shared socioeconomic pathways (SSPs) and the new scenarios that combine SSPs with representative concentration pathways (RCPs) for climate change impacts, adaptation, and vulnerability (IAV) research. It first provides an overview of uses of social–environmental scenarios in IAV studies and identifies the main shortcomings of earlier such scenarios. Second, the paper elaborates on two aspects of the SSPs and new scenarios that would improve their usefulness for IAV studies compared to earlier scenario sets: (i) enhancing their applicability while retaining coherence across spatial scales, and (ii) adding indicators of importance for projecting vulnerability. The paper therefore presents an agenda for future research, recommending that SSPs incorporate not only the standard variables of population and gross domestic product, but also indicators such as income distribution, spatial population, human health and governance.     

Detecting space–time patterns of disease risk under dynamic background population

Journal of Geographical Systems - We are able to collect vast quantities of spatiotemporal data due to recent technological advances. Exploratory space–time data analysis approaches can...     

Distribution and Abundance of Arsenic in the Soils and Sediments of O‘ahu,Hawai‘i

Lack of high-spatial-resolution soil and sediment arsenic data for Hawai‘i has generated substantial disagreement between researchers and regulators regarding the magnitude of natural levels of arsenic in Hawai‘i and rendered difficult the defining of areas of anthropogenically elevated arsenic. Our earlier research into the occurrence of arsenic in terrestrial and marine environments revealed widely disparate concentrations of arsenic with no apparent spatial pattern. To better understand the distribution and abundance of arsenic in soils and sediments of O‘ahu, we collected an additional 64 samples at locations chosen to represent different environments with varying degrees of human impact. We found surface arsenic values that ranged from 0.28 to 740 ppm with a median concentration of 8.1 ppm, which is above the global median of 5 ppm and US soil median of 5.2 ppm. Higher concentrations of arsenic (up to 913 ppm) were encountered at depth in soil cores. The median arsenic in streambed sediments from one of our earlier studies of 6.1 ppm was comparable to the conterminous US median of 6.3 ppm; however, we encountered arsenic concentrations as high as 43.9 ppm (median = 8.60 ppm, n = 75) in marine sediments in recent work off the leeward coast of O‘ahu. Overall, arsenic in the soils and sediments of O‘ahu is elevated relative to world and national values, but there still is no readily discernible pattern in the distribution of arsenic to explain these elevated values.     

巴丹吉林沙漠南缘的植物固沙问题

在野外考察的基础上,选择13个典型样地,研究了巴丹吉林沙漠南缘植被组成、群落特征和植被格局。结果表明：调查的样地中有荒漠植物31种,其中灌木12种,多年生草本11种,一二年生草本8种。种群密度3 000—14 000株·hm^-2,优势种在群落中地位显著,群落稳定性较差;植被斑块面积小、最大斑块指数低。沙漠南缘年降水量虽然仅100 mm左右,但有霸王（Zygophyllum xanthoxylon）、红砂（Reaumuria soongarica）和沙蒿（Artemisia desertorum）等灌木和半灌木天然植物群落分布,有白刺（Nitraria tangutorum）和膜果麻黄（Ephedra przewalskii）灌丛沙堆,沙丘上生长着沙拐枣（Calligonum mongolicum）、沙鞭（Psammochloa villosa）等种群生存,且在沙漠延伸带流动沙丘上已成功建立了梭梭（Haloxylon ammodendron）人工固沙植被,表明在巴丹吉林沙漠南缘建立以乡土植物为主的固沙植被是可行的。在未来研究中,应在山水林田湖草沙生命共同体理念下加强从区域尺度上解析水、植被和沙的关系,系统了解生态系统的原真性、完整性和连通性及生态系统稳定性维持等问题,优化生态景观格局,确定生态保护目标和建设规模,同时要加强对乡土植物适应干旱风沙机制和扩繁保育技术研究,以便为区域生态建设和生态保护提供科技支撑。     

A GNSS interference identification using an adaptive cascading IIR notch filter

A low-complexity time-domain approach for global navigation satellite systems is proposed to detect and identify single-tone, multi-tone, swept continuous wave interference (CWI) and band-limited white Gaussian noise (BLWN). An adaptive notch filter and adaptive cascading filter structure are employed to identify the type of interference signals. The number of the cascading stages is selected by comparing the total power in receiver bandpass, and after, passing the adaptive notch filter. For this reason, the proposed filter structure is more efficient in identifying and mitigating interference signals than the conventional filter structure. In addition, the automatic gain control gain is used to detect the existence of continuous wave interference. The performance of the interference detection and identification method is evaluated for the cases of GPS signal in the presence of single-tone, multi-tone, swept CWI and BLWN.     

Mapping collective human activity in an urban environment based on mobile phone data

Identifying and characterizing variations of human activity – specifically changes in intensity and similarity – in urban environments provide insights into the social component of those eminently complex systems. Using large volumes of user-generated mobile phone data, we derive mobile communication profiles that we use as a proxy for the collective human activity. In this article, geocomputational methods and geovisual analytics such as self-organizing maps (SOM) are used to explore the variations of these profiles, and its implications for collective human activity. We evaluate the merits of SOM as a cross-dimensional clustering technique and derived temporal trajectories of variations within the mobile communication profiles. The trajectories’ characteristics such as length are discussed, suggesting spatial variations in intensity and similarity in collective human activity. Trajectories are linked back to the geographic space to map the spatial and temporal variation of trajectory characteristics. Different trajectory lengths suggest that mobile phone activity is correlated with the spatial configuration of the city, and so at different times of the day. Our approach contributes to the understanding of the space-time social dynamics within urban environments.     

Laboratory plasma dynamos, astrophysical dynamos and magnetic helicity evolution

The term 'dynamo' means different things to the laboratory fusion plasma and astrophysical plasma communities. To alleviate the resulting confusion and to facilitate interdisciplinary progress, we pinpoint conceptual differences and similarities between laboratory plasma dynamos and astrophysical dynamos. We can divide dynamos into three types: 1. magnetically dominated helical dynamos which sustain a large-scale magnetic field against resistive decay and drive the magnetic geometry towards the lowest energy state, 2. flow-driven helical dynamos which amplify or sustain large-scale magnetic fields in an otherwise turbulent flow and 3. flow-driven non-helical dynamos which amplify fields on scales at or below the driving turbulence. We discuss how all three types occur in astrophysics whereas plasma confinement device dynamos are of the first type. Type 3 dynamos require no magnetic or kinetic helicity of any kind. Focusing on Types 1 and 2 dynamos, we show how different limits of a unified set of equations for magnetic helicity evolution reveal both types. We explicitly describe a steady-state example of a Type 1 dynamo, and three examples of Type 2 dynamos: (i) closed volume and time dependent; (ii) steady state with open boundaries; (iii) time dependent with open boundaries.     

A geology of the road

Before the Roman came to Rye or out to Severn strode,
The rolling English drunkard made the rolling English road.     

Mid-infrared, spatially resolved spectroscopy of the nucleus of the Circinus galaxy

High spatial resolution spectroscopy at 8–13 μm with T-ReCS on Gemini-S has revealed striking variations in the mid-infrared emission and absorption in the nucleus of the Circinus galaxy (hereafter Circinus) on subarcsecond scales. The core of Circinus is compact and obscured by a substantial column of cool silicate dust. Weak extended emission to the east and west coincides with the coronal line region and arises from featureless dust grains which are probably heated by line emission in the coronal emission zone. The extended emission on the east side of the nucleus displays a much deeper silicate absorption than that on the west, indicating significant columns of cool material along the line of sight and corresponding to an additional extinction of   A_V ∼ 25 mag  . Emission bands from aromatic hydrocarbons are not subject to this additional extinction, are relatively weak in the core and in the coronal line region, and are much more spatially extended than the continuum dust emission; they presumably arise in the circumnuclear star-forming regions. These data are interpreted in terms of an inclined disc-like structure around the nucleus extending over tens of parsecs and possibly related to the inner disc found from observations of water masers by Greenhill et al..