Lithium in the aragonite skeletons of massive Porites corals: A new tool to reconstruct tropical sea surface temperatures

Previous studies have demonstrated the potential for the Li content of coral aragonite to record information about environmental conditions, but no detailed study of tropical corals exists. Here we present the Li and Mg to Ca ratios at a bimonthly to monthly resolution over 25 years in two modern Porites corals, the genus most often used for paleoclimate reconstructions in the tropical Indo-Pacific. A strong relationship exists between coral Li/Ca and locally measured SST, indicating that coral Li/Ca can be used to reconstruct tropical SST variations. However, Li/Ca ratios of the skeleton deposited during 1979-1980 do not track local SST well and are anomalously high in places. The Mg/Ca ratios of this interval are also anomalously high, and we suggest Li/Ca can be used to reconstruct tropical SST only when Mg/Ca data are used to carefully screen for relatively rare biological effects. Mg/Li or Li/Mg ratios provide little advantage over Li/Ca ratios, except that the slope of the Li/Mg temperature relationship is more similar between the two corals. The Mg/Li temperature relationship for the coral that experienced a large temperature range is similar to that found for cold water corals and aragonitic benthic foraminifera in previous studies. The comparison with data from other biogenic aragonites suggests the relationship between Li/Mg and water temperature can be described by a single exponential relationship. Despite this hint at an overarching control, it is clear that biological processes strongly influence coral Li/Ca, and more calibration work is required before widely applying the prox

Recruitment Variability in North Atlantic Cod and Match-Mismatch Dynamics

Background Fisheries exploitation, habitat destruction, and climate are important drivers of variability in recruitment success. Understanding variability in recruitment can reveal mechanisms behind widespread decline in the abundance of key species in marine and terrestrial ecosystems. For fish populations, the match-mismatch theory hypothesizes that successful recruitment is a function of the timing and duration of larval fish abundance and prey availability. However, the underlying mechanisms of match-mismatch dynamics and the factors driving spatial differences between high and low recruitment remain poorly understood. Methodology/Principal Findings We used empirical observations of larval fish abundance, a mechanistic individual-based model, and a reanalysis of ocean temperature data from 1960 to 2002 to estimate the survival of larval cod (Gadus morhua). From the model, we quantified how survival rates changed during the warmest and coldest years at four important cod spawning sites in the North Atlantic. The modeled difference in survival probability was not large for any given month between cold or warm years. However, the cumulative effect of higher growth rates and survival through the entire spawning season in warm years was substantial with 308%, 385%, 154%, and 175% increases in survival for Georges Bank, Iceland, North Sea, and Lofoten cod stocks, respectively. We also found that the importance of match-mismatch dynamics generally increased with latitude. Conclusions/Significance Our analyses indicate that a key factor for enhancing survival is the duration of the overlap between larval and prey abundance and not the actual timing of the peak abundance. During warm years, the duration of the overlap between larval fish and their prey is prolonged due to an early onset of the spring bloom. This prolonged season enhances cumulative growth and survival, leading to a greater number of large individuals with enhanced potential for survival to recruitment

A verification framework for interannual-to-decadal predictions experiments

Decadal predictions have a high profile in the climate science community and beyond, yet very little is known about their skill. Nor is there any agreed protocol for estimating their skill. This paper proposes a sound and coordinated framework for verification of decadal hindcast experiments. The framework is illustrated for decadal hindcasts tailored to meet the requirements and specifications of CMIP5 (Coupled Model Intercomparison Project phase 5). The chosen metrics address key questions about the information content in initialized decadal hindcasts. These questions are: (1) Do the initial conditions in the hindcasts lead to more accurate predictions of the climate, compared to un-initialized climate change projections? and (2) Is the prediction model’s ensemble spread an appropriate representation of forecast uncertainty on average? The first question is addressed through deterministic metrics that compare the initialized and uninitialized hindcasts. The second question is addressed through a probabilistic metric applied to the initialized hindcasts and comparing different ways to ascribe forecast uncertainty. Verification is advocated at smoothed regional scales that can illuminate broad areas of predictability, as well as at the grid scale, since many users of the decadal prediction experiments who feed the climate data into applications or decision models will use the data at grid scale, or downscale it to even higher resolution. An overall statement on skill of CMIP5 decadal hindcasts is not the aim of this paper. The results presented are only illustrative of the framework, which would enable such studies. However, broad conclusions that are beginning to emerge from the CMIP5 results include (1) Most predictability at the interannual-to-decadal scale, relative to climatological averages, comes from external forcing, particularly for temperature; (2) though moderate, additional skill is added by the initial conditions over what is imparted by external forcing alone; however, the impact of initialization may result in overall worse predictions in some regions than provided by uninitialized climate change projections; (3) limited hindcast records and the dearth of climate-quality observational data impede our ability to quantify expected skill as well as model biases; and (4) as is common to seasonal-to-interannual model predictions, the spread of the ensemble members is not necessarily a good representation of forecast uncertainty. The authors recommend that this framework be adopted to serve as a starting point to compare prediction quality across prediction systems. The framework can provide a baseline against which future improvements can be quantified. The framework also provides guidance on the use of these model predictions, which differ in fundamental ways from the climate change projections that much of the community has become familiar with, including adjustment of mean and conditional biases, and consideration of how to best approach forecast uncertainty

Gaming the future of an urban network

Scenario and gaming techniques have a number of complementary characteristics. In this article, the design and evaluation of a gaming-scenario experiment for the exploration of development planning in an urban network in the Netherlands is presented. Two gaming sessions were held using two long-term scenarios (2030) as varying contexts. The combined gaming-scenario approach made it possible to evaluate the impact of external future developments and trends on the administrative and spatial development. Evaluation results of the gaming experiment indicate that the gaming-scenario approach generated new and critical insights on development planning and the future of the urban network. Through the game, the principal, the game leaders but most of all the stakeholder-participants experienced and realized that the management of development planning in urban networks is a very difficult task and is full of pitfalls

Oeuvres choisies de Dancourt, avec des remarques, des notices, et l'examen de chaque pièce,

Bibliothèque dramatique, ou Répertoire universel du théâtre français. 2. sér., t. 8, 10.Mode of access: Internet

The Urban Network Game: A Simulation of the Future of Joint City Interests

In a thriving, densely populated and urbanized country like the Netherlands, space is at a premium. With the steady economic growth of the 1990s and the construction and expansion of homes, business parks and infrastructure, the available space and the environment are coming under increasing pressure. Major changes are also taking place on an administrative level in the Netherlands. In some cases, influential new joint ventures are formed between public, private, and social parties (Frieling 2000). The social and administrative dynamic, and the tension that this creates in relation to spatial quality requirements, is turning into a major challenge for spatial policy. Numerous advisory bodies and policymakers are therefore advocating a spatial development policy (WRR 1998) or development planning (VROM 2001, 2002). Development planning is the opposite of admittance planning and provides increased scope for the initiatives and investments of local governments and private and social parties. Instead of passively resisting activities and exhibiting too little flexibility, governments must aim at actively entering into partnerships with other governments, the business sector, and social organizations. Together, they must develop and realize interrelated, creative concepts, projects, and programs (WRR 1998; Healey 2000;Teisman 1997;VROM Council 2001). According to the Netherlands' Ministry of Housing, Spatial Planning, and the Environment (VROM 2002), development planning requires: "active intervention by means of investments made by both public and private parties. The State shall then provide policy frameworks for the investments and harmonize them with each other. This provides scope for the initiatives of lower governments, market parties, and social organizations and supports them." Innovation, future orientation, integral concepts, stakeholder planning and new ways of public private financing, and cooperation are some of the relevant characteristics ascribed to development planning. However, the above description shows that development planning may be an interesting concept but it is also very abstract and ambiguous. Moreover, the real question is how development planning works in practice and whether it actually differs from admittance planning. How can such notions as stakeholder planning, future orientation, and innovation be realized in a region? How do spatial investments, innovation, and integral concepts come about? Does development planning really result in spatial and administrative innovation, as one would expect in theory? What is clear, however, is that development planning will have to be tackled by governments and private and social parties on a regional/provincial level. Against this background, the Netherlands Institute for Spatial Research (RPB), established on 1 January 2002, asked the Delft University of Technology to design a simulation game in which the concept of development planning can be tested in a safe environment (Mayer and Veeneman 2002; Mayer et al. 2004)