Turkey Lakes Watershed,Ontario, Canada: 40 years of interdisciplinary whole-ecosystem research

The Turkey Lakes Watershed (TLW) study is a federal, interdepartmental study established in 1979 to investigate the effects of acid rain on terrestrial and aquatic ecosystems. The 10.5 km² watershed, located in the Eastern Temperate Mixed Forest on the Canadian Shield, has been the site of multidisciplinary studies on biogeochemical and ecological processes conducted across plot to catchment scales. The whole-ecosystem investigative approach was adopted from the outset and has allowed research to evolve from its original (and continuing) acidification focus to include investigations on the effects of climate change, forest harvesting and other forest ecosystem perturbations. The extensive scientific and support infrastructure allows for collection of a comprehensive data record essential for understanding long-term environmental trends. Data include atmospheric deposition, meteorology, stream hydrology and chemistry, soil, pore and ground water properties, understory and overstory vegetation, lake and outflow physical and chemical properties, and aquatic macroinvertebrate and fish community composition and abundance. These data have contributed to over 400 published research papers and graduate theses. The watershed has also figured prominently in many continent-wide comparisons advancing fundamental watershed theory. The knowledge gained at TLW has influenced pollutant emission and natural resource management policies provincially, nationally and internationally.     

一里坪矿区卤水自然蒸发试验研究

在青海省重点科技攻关项目"柴达木盆地一里坪凹陷开采方法及找矿方向研究"(2005-G-131)基础上,对一里坪锂硼钾矿区卤水进行了自然蒸发试验研究。     

Experiments using new initial soil moisture conditions and soil map in the Eta model over La Plata Basin

An effort towards a more accurate representation of soil moisture and its impact on the modeling of weather systems is presented. Sensitivity tests of precipitation to soil type and soil moisture changes are carried out using the atmospheric Eta model for the numerical simulation of the development of a mesoscale convective system over northern Argentina. Modified initial soil moisture conditions were obtained from a hydrological balance model developed and running operationally at INPE. A new soil map was elaborated using the available soil profile information from Brazil, Paraguay, Uruguay, and Argentina and depicts 18 different soil types. Results indicate that more accurate initial soil moisture conditions and incorporating a new soil map with hydraulic parameters, more representative of South American soils, improve daily total precipitation forecasts both in quantitative and spatial representations.     

Effect of the radiative background flux in convection

Numerical simulations of turbulent stratified convection are used to study models with approximately the same convective flux, but different radiative fluxes. As the radiative flux is decreased, for constant convective flux: the entropy jump at the top of the convection zone becomes steeper, the temperature fluctuations increase and the velocity fluctuations decrease in magnitude, and the distance that low entropy fluid from the surface can penetrate increases. Velocity and temperature fluctuations follow mixing length scaling laws. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Functional relation of land surface albedo with climatological variables: a review on remote sensing techniques and recent research developments

Surface albedo has been documented as one of the Essential Climate Variables (ECV) of the Global Climate Observing System (GCOS) that governs the Earth's Radiation Budget. The availability of surface albedo data is necessary for a comprehensive environmental modelling study. Thus, both temporal and spatial scale issues need to be rectified. This study reports about the availability of surface albedo data through in-situ and remote sensing satellite observations. In this paper, we reviewed the existing models for surface albedo derivation and various initiatives taken by related environmental agencies in order to understand the issues of climate with respect to surface albedo. This investigation evaluated the major activities on albedo-related research specifically for the retrieval methods used to derive the albedo values. Two main existing albedo measurement methods are derived through in-situ measurement and remotely sensed observations. In-situ measurement supported with number of instruments and techniques such aspyrheliometers, pyranometers and Baseline Surface Radiation Network (BSRN) and remotely sensed observations using angularly integrated Bi-directional Reflectance Distribution Function (BRDF) by both geostationary and polar orbit satellites. The investigation results reveals that the temporal and spatial scaling is the major issues when the albedo values are needed for microclimatic study, i.e. high-resolution time-series analyses and at heterogeneity and impervious surface. Thus, an improved technique of albedo retrieval at better spatial and temporal scale is required to fulfil the need for such kind of studies. Amongst many others, there are two downscaling methods that have been identified to be used in resolving the spatial scaling biased issues: Smoothing Filter-based Intensity Modulation (SFIM) and Pixel Block Intensity Modulation (PBIM). The temporal issues can be resolved using the multiple regression techniques of land surface temperature, selected air quality parameters, aerosol and daily skylight.     

Susceptibility of fish to Chattonella marina is determined by its tolerance to hypoxia

The harmful alga Chattonella marina has caused massive fish kills and economic losses worldwide. However, the fish kill mechanisms by C. marina have not been identified. The present study has confirmed that a significant elevation of blood osmolality is the universal response in moribund fish exposed to C. marina and the possible reasons leading to contradictory reports were identified. Both osmotic distress and respiratory impairment are important mechanisms leading to fish kill by C. marina. The susceptibility of marine fish to C. marina appears to be inversely related to their tolerance to hypoxia, with the hypoxia intolerant goldlined seabream being the most susceptible, and the hypoxia tolerant green grouper being the most tolerant to C. marina. Further studies in the marine medaka (Oryzias melastigma) showed that fish susceptibility to C. marina is directly related to susceptibility of the fish to hypoxia, but not related to its tolerance to hypersalinity stress.     

Entrepreneurial city and the restructuring of urban space in Shanghai Expo

ABSTRACT

This study examines the restructuring of urban space brought about by Shanghai Expo. The focus is on how the municipal government strategically makes use of this mega-event program to proactively implement two entrepreneurial spatial policies, namely economic restructuring and population decentralization. Specifically, it critically investigates the omnipotent government’s policies in terms of industrial relocation and residential resettlement leading up to the Shanghai Expo. Shanghai’s entrepreneurial city building, at the metropolitan level, has long been associated with the optimization of spatial structure. The empirical findings reveal that the negotiations involved in relocating enterprises were tougher when they took place within the state system, as compared to those between the government and foreign or private sectors. At the same time, social groups remained excluded from decision-making processes for resettlement, and there was a downscaling of governance, which contributed to improved efficiency of the resettlement work. The Shanghai municipal government was key to the restructuring and entrepreneurial city building, engaging, on the one hand, in negotiations on spatial relocation with central state-owned enterprises (SOEs) at the level of the central government and mobilizing, on the other hand, lower-tier government authorities to deliver the resettlement plan. This paper argues that the development of the entrepreneurial city in Shanghai depends essentially on the way local government implemented the policy and that an integrated approach is significant to attaining the goals and objectives.     

Vertical mixing of oil droplets by breaking waves

Oil spilled on a sea surface can be dispersed by a variety of natural processes, of which the influence of breaking waves is dominant. Breaking waves are able to split the slick into small droplets, facilitating oil mixing in the water column. Vertical dynamics of the droplets plays a major role in the oil mass exchange between the slick and the water column. In this paper a mathematical model of oil droplet mixing by breaking waves is developed. The model uses a kinetic approach to describe the vertical exchange of the droplets at the interface between the slick and the water column. The majority of the coefficients and parameters are conveniently combined into a single "mixing factor". The model is verified using sensitivity analysis and empirical formulae of other authors. The model permits a rapid estimation of the amount of dispersed oil under the breaking waves. The ultimate goal of the research is to parameterise influence of breaking waves on vertical mixing of oil droplets to be used in a general 3-D oil spill model.