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111.
Austin H. Becker Michele Acciaro Regina Asariotis Edgard Cabrera Laurent Cretegny Philippe Crist Miguel Esteban Andrew Mather Steve Messner Susumu Naruse Adolf K. Y. Ng Stefan Rahmstorf Michael Savonis Dong-Wook Song Vladimir Stenek Adonis F. Velegrakis 《Climatic change》2013,120(4):683-695
With 80 % of world trade carried by sea, seaports provide crucial linkages in global supply-chains and are essential for the ability of all countries to access global markets. Seaports are likely to be affected directly and indirectly by climatic changes, with broader implications for international trade and development. Due to their coastal location, seaports are particularly vulnerable to extreme weather events associated with increasing sea levels and tropical storm activity, as illustrated by hurricane “Sandy”. In view of their strategic role as part of the globalized trading system, adapting ports in different parts of the world to the impacts of climate change is of considerable importance. Reflecting the views of a diverse group of stakeholders with expertise in climate science, engineering, economics, policy, and port management, this essay highlights the climate change challenge for ports and suggests a way forward through the adoption of some initial measures. These include both “soft” and “hard” adaptations that may be spearheaded by individual port entities, but will require collaboration and support from a broad range of public and private sector stakeholders and from society at large. In particular, the essay highlights a need to shift to more holistic planning, investment and operation. 相似文献
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Stefan J. Medwadowski 《Astrophysics and Space Science》1989,160(1-2):33-43
The structure of the Keck Telescope is briefly described. The design required an innovative approach made necessary by the revolutionary nature of the segmented primary mirror, by the very stringent weight and cost limitations, and by observational and operational needs. Analysis of a progressively more detailed computer model predicts that all design objectives will be met, as shown in a summary of performance characteristics. The paper is illustrated with a number of drawings.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2 1988. 相似文献
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The mesoscale convection life cycle: Building block or prototype for large-scale tropical waves? 总被引:1,自引:0,他引:1
Brian Mapes Stefan Tulich Jialin Lin Paquita Zuidema 《Dynamics of Atmospheres and Oceans》2006,42(1-4):3
A cumulonimbus cloud may ascend and spawn its anvil cloud, precipitation, and downdrafts within an hour or so. This paper inquires why a similar progression of events (life cycle) is observed for tropical weather fluctuations with time scales of hours, days, and even weeks. Regressions using point data illustrate the characteristic unit of rain production: the mesoscale convective system (MCS), covering tens of kilometers and lasting several hours, with embedded convective rain cells. Meanwhile, averages over larger spatial areas indicate a self-similar progression from shallow to deep convection to stratiform anvils on many time scales.Synthetic data exercises indicate that simple superpositions of fixed-structure MCS life cycles (the Building Block hypothesis) cannot explain why longer period life cycles are similar. Rather, it appears that an MCS may be a small analogue or prototype of larger scale waves. Multiscale structure is hypothesized to occur via a Stretched Building Block conceptual model, in which the widths (durations) of zones of shallow, deep, and stratiform anvil clouds in MCSs are modulated by larger scale waves.Temperature (T) and humidity (q) data are examined and fed into an entraining plume model, in an attempt to elucidate their relative roles in these large-scale convection zone variations. T profile variations, with wavelengths shorter than troposphere depth, appear important for high-frequency ( 2–5-day period) convectively coupled waves, as density directly links convection (via buoyancy) and large-scale wave dynamics (via restoring force). Still, the associated q anomalies are several times greater than adiabatic, suggesting a strong amplification by shallow convective feedbacks. For lower frequency (intraseasonal) variability, q anomalies are considerably larger compared to T, and may be dominant. 相似文献
118.
Alexander M. Heyng Christoph Mayr Andreas Lücke Bernd Striewski Stefan Wasteg?rd Holger Wissel 《Journal of Paleolimnology》2012,48(2):351-366
Maar lakes in the Auckland Volcanic Field are important high-resolution archives of Holocene environmental change in the Southern Hemisphere mid-latitudes. Stable carbon and nitrogen isotope analyses were applied on bulk organic matter and the green alga Botryococcus from a sediment core from Lake Pupuke (Auckland, North Island, New Zealand) spanning the period since 7,165?cal.?year BP. The origin of organic matter was established using total-organic?Ccarbon-to-nitrogen ratios (TOC/TN) as well as organic carbon (??13COM) and nitrogen (??15N) isotope composition of potential modern sources. This approach demonstrated that the contribution of allochthonous organic matter to the lake sediment was negligible for most of the record. The sedimentary TOC/TN ratios that are higher than Redfield ratio (i.e. >7) are attributed to N-limiting conditions throughout the record. Variations of nitrogen and carbon isotopes during the last 7,165?years are interpreted as changes in the dominant processes in the lake. While epilimnetic primary productivity controlled isotope composition before 6,600?cal.?year BP, microbial processes, especially denitrification and methane oxidation, caused overall shifts of the ??15N and ??13C values since the Mid-Holocene. Comparisons with climate reconstructions from the Northern Island suggest that changes in the wind-induced lake overturn and a shift to more pronounced seasonality were the most likely causes for lake-internal changes since 6,600?cal.?year BP. 相似文献
119.
Exploring the climate problems of Brazil’s Nordeste: a review 总被引:1,自引:0,他引:1
Stefan Hastenrath 《Climatic change》2012,112(2):243-251
This article reviews the exploration of the climate dynamics of Brazil’s Nordeste in the course of a century. The drought-prone and semi-arid northern Nordeste of Brazil experiences a short rainy season around March–April, when the interhemispheric gradient of sea surface temperature (SST) in the tropical Atlantic is weakest and the Intertropical Convergence Zone (ITCZ) reaches its southernmost position in the course of the annual cycle. The recurrent Secas (droughts) have a severe socio-economic impact. During drought years, the interhemispheric SST gradient in the tropical Atlantic is steep and the ITCZ stays far North, while the waters of the eastern equatorial Pacific tend to be anomalously warm. Based on the extensive diagnostic exploration of the circulation mechanisms of interannual climate variability, empirical methods have been developed for the forecasting of the Nordeste rainy season. These have been applied in the real-time prediction of seasonal rainfall anomalies throughout the last decade of the 20th century. 相似文献
120.
The objective of the study is to detect geographical and temporal variations of near surface air temperatures over Minnesota and Wisconsin, USA derived from the North American Regional Reanalysis (NARR) dataset. In addition, the study serves to assess the usefulness of NARR temperature data to analyze regional and local temperature variations. Particular emphasis was placed on the analyses on the temperature-modifying effects of the Great Lakes and large urban environments. We analyzed annual mean, daily maximum and minimum, and January minimum and July maximum temperatures for the period 1979–2006 by using methods such as ordinary kriging, principal component analysis, and the Mann–Kendall test. On a regional scale, we found significant effects of the latitude and the Great Lakes on the spatial variability of the data. Furthermore, we found clearly identifiable effects of large urban areas in the study region (Minneapolis—Saint Paul and Milwaukee), which are more evident in the principal component scores than in the temperature data themselves. While we failed to detect significant July maximum temperature trends, we detected significantly increasing trends in January minimum and mean annual temperature datasets in the eastern part of the region. Overall, the present study has demonstrated the potential of using NARR data for urban climate research. 相似文献