Results 1 - 10 of 633
Results 1 - 10 of 633. Search took: 0.022 seconds
|Sort by: date | relevance|
[en] Designing some long-lasting industrial assets necessitates an estimation of far future extremes. Extreme value estimation is commonly based on an application of the statistical extreme value theory (EVT), which requires that the studied variable is independent and identically distributed, or, at least, stationary. Climate variables exhibit different behaviors which potentially violate this assumption: Seasonality is generally the easiest to handle, and interannual variability is more complicated. Now, as far as temperature is concerned, an additional source of non-stationarity appears: the warming trend, whose interactions with interannual variability add another range of complexity. The approach proposed here is based on the construction of a standardized variable, whose extremes can be considered as stationary. This allows an application of EVT in better accordance with its assumptions. Recent works (Parey et al. in J Geophys Res Atmos 118:8285–8296, 2013. https://doi.org/10.1002/jgrd.50629 ) have shown that if optimized smooth trends in mean and standard deviation are removed from the temperature time series, then the extremes of the residuals can be considered as stationary. A statistical test has been designed to check this assumption. Here, the inference of high-temperature extremes from the extremes of this standardized variable and future mean and standard deviation projected at the desired time horizon, and given by climate model simulations, is further analyzed and justified.
[en] There are several reasons that the U. S. Global Change Research Program (USGCRP) has initiated the U.S. National Assessment: The Potential Consequences of Climate Variability and Change. The reasons all revolve around answering questions posed in Washington by members of Congress on behalf of their constituents as to why climate change concerns them. This workshop is part of the process for getting better answers to these questions. This paper briefly reviews the science of climate change and the human influence on climate change, discusses future climate change, and considers national and international perspectives on global change. It discusses the potential for mitigation of climate change and the need to cope with climate change. The author explains the U.S. National Assessment
[en] In equation (2) the term “P(L ∨ R, A5)” should be replaced with “P(L|R, A5)” and the term “P(R, A5) ∨ L” should be replaced with “P(R, A5|L)”. A typographical error replaced the symbol “|” with the symbol “∨”.
[en] In recent years, climate change has been one of the most complicated problems that human being has faced. Climate change adaptation (CCA) is considered to be an important component of risk management. In order to achieve adaptation, it is necessary to determine the indicators influencing adaptation in each community and this requires measurement and standard tools. The aim of this study is to determine and categorize the indicators of CCA. International electronic databases including Science Direct, Web of Science, Scopus, Google Scholar were investigated for only articles published in English language. In addition, Iranian databases including Irandoc, SID, and Magiran were investigated. There was no limitation on the methods of studies. Furthermore, snowball method was used for finding more articles while the ProQuest database was searched for related dissertations. The published documents from 1990 to November 2017 were gathered in this study. Out of 4439 publications initially search, 152 full texts were investigated. Finally, a total of 45 potentially relevant citations were included for full text review; in addition, fourteen other sources were investigated. Using snowball method, we found 24 other articles that were included in our final result. From the searches, 176 indicators were identified, while seven main domains were mentioned. Since in the articles, domains of adaptation are not in the form of a model, it is better to focus on this issue in the future and it seems that prioritizing and weighting domains in adaptation in different communities with different needs are an important issue.
[en] Coastline is an environmental place with assets as recreational and productive value. Monitoring of State is necessary for management of reactions to human action, extreme storms or climate change needs indicators as instruments for measuring evolution. Indicators need to be simple, easy to gauge and to make public, so as to be used in Agendas 21 or human development sustain ability.geologic couches associated to storm high energy and rocks visible s in beaches can be used as indicators. Playa Ramirez, near the center city, shows a high energy couch e mostly linked to a great storm in August 2005 and gneiss rocks from Montevideo formation more o less covered with sand responding to storms and currents transport balance. Both can be indicators integrating storms and currents effects useful for monitoring specific systems, which are to be identified in each part of the coast. (author)
[en] Research highlights: → This study reports the first observation of predominant even carbon-numbered n-alkanes of sediments in the continuous lacustrine-sedimentary section (Maogou) from the Late Miocene to the Early Pliocene (13-4.4 Ma) in the Linxia Basin, NE Tibetan Plateau. → Certain types of special autochthonous bacteria are a possible source for the special distribution of even carbon-numbered n-alkanes in lacustrine sediments. → These bacteria may have a high production rate in weak oxic-anoxic and arid depositional environments, in which a variety of geochemical parameters have recorded palaeoclimate change. → A close correspondence among the low ratio of n-C27/n-C31, the heavy δ13C values of TOC and a strong even carbon-number predominance (low OEP16-20 values) from approximately 6.5 to 4.4 Ma and at approximately 8 Ma in the studied section suggests that n-alkanes with a high predominance of even carbon-numbers may be treated as geochemical proxies for arid climate. - Abstract: This study reports the first observation of predominant even C-numbered n-alkanes from sediments in the continuous lacustrine-sedimentary section (Maogou) from the Late Miocene to the Early Pliocene (13-4.4 Ma) in the Linxia Basin, NE Tibetan Plateau. The n-alkanes showed a bimodal distribution that is characterised by a centre at n-C16-n-C20 with maximum values at n-C18 and n-C27-n-C31 as well as at n-C29. The first mode shows a strong even C-number predominance (OEP16-20 0.34-0.66). In contrast, the second mode has a strong odd C-number predominance (OEP27-31 1.20-2.45). Certain types of special autochthonous bacteria are a possible source for this distribution of even C-numbered n-alkanes in lacustrine sediments. These bacteria may have a high production rate in weak oxic-anoxic and arid depositional environments, in which a variety of geochemical parameters have recorded palaeoclimate change.
[en] The health of the world's oceans and their impact on global environmental and climate change make the development of cabled observing systems vital and timely as a data source and archive of unparalleled importance for new discoveries. The VENUS and NEPTUNE Canada observatories are on the forefront of a new generation of ocean science and technology. Funding of over $100M, principally from the Governments of Canada and BC, for these two observatories supports integrated ocean systems science at a regional scale enabled by new developments in powered sub-sea cable technology and in cyber-infrastructure that streams continuous real-time data to Internet-based web platforms. VENUS is a coastal observatory supporting two instrumented arrays in the Saanich Inlet, near Victoria, and in the Strait of Georgia, off Vancouver. NEPTUNE Canada is an 800 km system on the Juan de Fuca Plate off the west coast of British Columbia, which will have five instrumented nodes in operation over the next 18 months. This paper describes the development and management of these two observatories, the principal research themes, and the applications of the research to public policy, economic development, and public education and outreach. Both observatories depend on partnerships with universities, government agencies, private sector companies, and NGOs. International collaboration is central to the development of the research programs, including partnerships with initiatives in the EU, US, Japan, Taiwan and China.