ABSTRACTIt has been frequently observed that there are surface cold patches (SCPs) in the Yellow Sea in summer. Although previous studies based on monthly mean temperature distribution found that these SCPs are a result of tidal mixing and tide-induced upwelling, tidal mixing and upwelling alone cannot explain all the occurrences. In our study we found that the three typical patches, namely, the Shandong SCP, the Subei SCP, and the Mokpo SCP, have different temporal patterns over a spring–neap tidal cycle; hence, they have different generating mechanisms. Based on a multiple-year simulation, the latter two show conspicuous spring–neap variations. The highest temperature occurs during the neap tide phase (about two days after a quarter moon). Because of weak upwelling and mixing, strong stratification is established and the SCPs are suppressed or even disappear. The opposite holds for the spring tide phase (about two days after a new or full moon). This is quite different from the Shandong SCP, which does not display a distinct difference between spring and neap tides. Buoy observations and composite analyses with data from the Moderate Resolution Imaging Spectroradiometer (MODIS) further support this conclusion. 相似文献
Brazil's nationally determined contribution (NDC) pledged under the Paris Agreement has marked a new stage in its climate policy towards strengthening low-carbon economic development beyond the recent drastic cuts in emissions from deforestation. Brazil especially means to limit oil consumption driven by future economic growth and to increase energy efficiency and biofuel use in the transport sector. On the other hand, Brazil still aspires to become a major petroleum province given its huge reserves of ‘pre-salt’ oil. This article aims to clarify under what conditions low-carbon economic development and oil exploration can possibly be combined in Brazil and what would be the energy system, environmental and macroeconomic implications of enabling policies for doing so. To address these questions, an energy–economy computable general equilibrium (CGE) model of the Brazilian economy is used to simulate alternative scenarios up to 2030. The results first show that implementing the most recent energy plans, which take into account the new economic reality in Brazil, should lead to over 20% lower domestic CO2 emissions in 2030 than the indicative NDC target, and to the export of the bulk of newfound crude oil. Second, with the same level of oil production, deeper domestic decarbonization, triggered by additional carbon pricing and sustainable efficiency measures, appears achievable with very small gross domestic product (GDP) loss and maximum oil exports, while being aligned with a 2°C emission pathway. However, (i) extra oil exports may induce net additional emissions outside Brazil and be seen as a perverse incentive and (ii) the economic growth strategy based on high oil exports may hinder the necessary diversification of the Brazilian economy.
Key policy insights
Low-carbon development goals will strongly interact with oil policy in Brazil.
The 2030 NDC target should be easy to achieve considering the new economic reality in Brazil.
Deeper domestic decarbonization is achievable with very limited GDP loss and significant oil exports, while being aligned with a 2°C emission pathway.
A broad strategic vision is needed to reconcile climate policy, energy policy and other economic development objectives.
This article shows the potential impact on global GHG emissions in 2030, if all countries were to implement sectoral climate policies similar to successful examples already implemented elsewhere. This assessment was represented in the IMAGE and GLOBIOM/G4M models by replicating the impact of successful national policies at the sector level in all world regions. The first step was to select successful policies in nine policy areas. In the second step, the impact on the energy and land-use systems or GHG emissions was identified and translated into model parameters, assuming that it would be possible to translate the impacts of the policies to other countries. As a result, projected annual GHG emission levels would be about 50 GtCO2e by 2030 (2% above 2010 levels), compared to the 60 GtCO2e in the ‘current policies’ scenario. Most reductions are achieved in the electricity sector through expanding renewable energy, followed by the reduction of fluorinated gases, reducing venting and flaring in oil and gas production, and improving industry efficiency. Materializing the calculated mitigation potential might not be as straightforward given different country priorities, policy preferences and circumstances.
Key policy insights
Considerable emissions reductions globally would be possible, if a selection of successful policies were replicated and implemented in all countries worldwide.
This would significantly reduce, but not close, the emissions gap with a 2°C pathway.
From the selection of successful policies evaluated in this study, those implemented in the sector ‘electricity supply’ have the highest impact on global emissions compared to the ‘current policies’ scenario.
Replicating the impact of these policies worldwide could lead to emission and energy trends in the renewable electricity, passenger transport, industry (including fluorinated gases) and buildings sector, that are close to those in a 2°C scenario.
Using successful policies and translating these to policy impact per sector is a more reality-based alternative to most mitigation pathways, which need to make theoretical assumptions on policy cost-effectiveness.
The Neem tree, the oil of which has a long history of pesticide, fertilizer and medicinal use in India, has been studied extensively for its organic compounds. Here we present a physical, mineralogical and geochemical database resulting from the analyses of two Neem soil profiles (epipedons) in India. Neem tree derivatives are used in the manufacture of a variety of products, from anti‐bacterial drugs and insecticides to fertilizers and animal feeds. A preliminary geochemical and mineralogical analysis of Neem soils is made to explore the potential for chemical links between Neem tree derivatives and soils. Physical soil characteristics, including colour, texture and clay mineralogy, suggest the two pedons formed under different hydrological regimes, and hence, are products of different leaching environments, one well‐drained site, the other poorly drained. Geochemically, the two Neem soils exhibit similarities, with elevated concentrations of Th and rare earth elements. These elements are of interest because of their association with phosphates, especially monazite and apatite, and the potential link to fertilizer derivatives. Higher concentrations of trace elements in the soils may be linked to nutritional derivatives and to cell growth in the Neem tree. 相似文献
Logistic regression has been used in the study to integrate indicator patterns for estimation of the probability of occurrence of gold deposits in a part of the auriferous Archaean Hutti–Maski schist belt. Data used consist of categorical and continuous variables obtained from a coded lineament map and geochemical anomaly maps of the pathfinder elements of gold in soil and groundwater. Main effects and interactions of the variables studied were used in formulating the logistic regression model. Regression models using lineament-proximity data, combined with soil and groundwater geochemical anomalies were tested on parts of the schist belt with data not used in estimation of model parameters. Predicted probabilities greater than 0.9 identified known deposit locations in the area. 相似文献