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51.
Athena Coustenis Jonathan Lunine Jean-Pierre Lebreton Dennis Matson Christian Erd Kim Reh Patricia Beauchamp Ralph Lorenz Hunter Waite Christophe Sotin Leonid Gurvits Mathieu Hirtzig 《Earth, Moon, and Planets》2009,105(2-4):135-142
The Titan Saturn System Mission (TSSM) concept is composed of a TSSM orbiter provided by NASA that would carry two Titan in situ elements provided by ESA: the montgolfière and the probe/lake lander. One overarching goal of TSSM is to explore in situ the atmosphere and surface of Titan. The mission has been prioritized as the second Outer Planets Flagship Mission, the first one being the Europa Jupiter System Mission (EJSM). TSSM would launch around 2023–2025 arriving at Saturn 9 years later followed by a 4-year science mission in the Saturn system. Following delivery of the in situ elements to Titan, the TSSM orbiter would explore the Saturn system via a 2-year tour that includes Enceladus and Titan flybys before entering into a dedicated orbit around Titan. The Titan montgolfière aerial vehicle under consideration will circumnavigate Titan at a latitude of ~20° and at altitudes of ~10 km for a minimum of 6 months. The probe/lake lander will descend through Titan’s atmosphere and land on the liquid surface of Kraken Mare (~75° north latitude). As for any planetary space science mission, and based on the Cassini–Huygens experience, Earth-based observations will be synergistic and enable scientific optimization of the return of such a mission. Some specific examples of how this can be achieved (through VLBI and Doppler tracking, continuous monitoring of atmospheric and surface features, and Direct-to-Earth transmission) are described in this paper. 相似文献
52.
The amount of capital required to transition energy systems to low-carbon futures is very large, yet analysis of energy systems change has been curiously quiet on the role of capital markets in financing energy transitions. This is surprising given the huge role finance and investment must play in facilitating transformative change. We argue this has been due to a lack of suitable theory to supplant neoclassical notions of capital markets and innovation finance. This research draws on the notion from Planetary economics: Energy, climate change and the three domains of sustainable development, by Grubb and colleagues, that planetary economics is defined by three ‘domains’, which describe behavioural, neoclassical, and evolutionary aspects of energy and climate policy analysis. We identify first- and second-domain theories of finance that are well established, but argue that third-domain approaches, relating to evolutionary systems change, have lacked a compatible theory of capital markets. Based on an analysis of electricity market reform and renewable energy finance in the UK, the ‘adaptive market hypothesis' is presented as a suitable framework with which to analyse energy systems finance. Armed with an understanding of financial markets as adaptive, scholars and policy makers can ask new questions about the role of capital markets in energy systems transitions.Policy relevanceThis article explores the role of financial markets in capitalising low-carbon energy systems and long-term change. The authors demonstrate that much energy and climate policy assumes financial markets are efficient, meaning they will reliably capitalise low-carbon transitions if a rational return is created by subsidy regimes or other market mechanisms. The authors show that the market for renewable energy finance does not conform to the efficient markets hypothesis, and is more in line with an ‘adaptive’ markets understanding. Climate and energy policy makers that design policy, strategy, and regulation on the assumption of efficient financial markets will not pay attention to structural and behavioural constraints on investment; they risk falling short of the investment levels needed for long-term systems change. In short, by thinking of financial markets as adaptive, the range of policy responses to enable low-carbon investment can be much broader. 相似文献
53.
54.
V. Formisano E. D'Aversa K.H. Baines R.H. Brown F. Capaccioni R.N. Clark D.P. Cruikshank R. Jaumann D.L. Matson V. Mennella P.D. Nicholson C. Sotin G. Hansen M. Showalter 《Icarus》2003,166(1):75-84
We report unusual and somewhat unexpected observations of the jovian satellite Io, showing strong methane absorption bands. These observations were made by the Cassini VIMS experiment during the Jupiter flyby of December/January 2000/2001. The explanation is straightforward: Entering or exiting from Jupiter's shadow during an eclipse, Io is illuminated by solar light which has transited the atmosphere of Jupiter. This light, therefore becomes imprinted with the spectral signature of Jupiter's upper atmosphere, which includes strong atmospheric methane absorption bands. Intercepting solar light refracted by the jovian atmosphere, Io essentially becomes a “mirror” for solar occultation events of Jupiter. The thickness of the layer where refracted solar light is observed is so large (more than 3000 km at Io's orbit), that we can foresee a nearly continuous multi-year period of similar events at Saturn, utilizing the large and bright ring system. During Cassini's 4-year nominal mission, this probing technique should reveal information of Saturn's atmosphere over a large range of southern latitudes and times. 相似文献
55.
Dennis L. Matson Julie C. Castillo-Rogez Ashley Gerard Davies Torrence V. Johnson 《Icarus》2012,221(1):53-62
The eruptive plumes and large heat flow (~15 GW) observed by Cassini in the South Polar Region of Enceladus may be expressions of hydrothermal activity inside Enceladus. We hypothesize that a subsurface ocean is the heat reservoir for thermal anomalies on the surface and the source of heat and chemicals necessary for the plumes. The ocean is believed to contain dissolved gases, mostly CO2 and is found to be relatively warm (~0 °C). Regular tidal forces open cracks in the icy crust above the ocean. Ocean water fills these fissures. There, the conditions are met for the upward movement of water and the dissolved gases to exsolve and form bubbles, lowering the bulk density of the water column and making the pressure at its bottom less than that at the top of the ocean. This pressure difference drives ocean water into and up the conduits toward the surface. This transportation mechanism supports the thermal anomalies and delivers heat and chemicals to the chambers from which the plumes erupt. Water enters these chambers and there its bubbles pop and loft an aerosol mist into the ullage. The exiting plume gas entrains some of these small droplets. Thus, nonvolatile chemical species in ocean water can be present in the plume particles. A CO2 equivalent-gas molar fraction of ~4 × 10?4 for the ocean is sufficient to support the circulation. A source of heat is needed to keep the ocean warm at ~0 °C (about two degrees above its freezing point). The source of heat is unknown, but our hypothesis is not dependent on any particular mechanism for producing the heat. 相似文献
56.
Rafael Ferreiro M?hlmann ?mer Bozkaya Sébastien Potel Ronan Le Bayon Branimir ?egvi? Fernando Nieto 《Swiss Journal of Geoscience》2012,105(2):121-152
Low-temperature metamorphic petrology occupies the P?CT field between sedimentary and metamorphic petrology. Two important pillars of low-temperature metamorphism are coal petrology and clay mineralogy. When low temperature petrology was established bridging a hiatus between the two classical geological disciplines of sedimentary geology and metamorphic petrology, geologists faced a need for the usage of different terminology tenets. Martin Frey and Bernard Kübler were two pioneers in low-grade metamorphic petrology. They focused their research on clarifying the relationships of clay mineralogy and organic petrology to metamorphic pressure (P) and temperature (T) conditions. The ultimate aim of M. Frey and B. Kübler was to establish a correlation between clay indices and organic parameters for different geodynamic setting and therefore for various pressure?Ctemperature (P?CT) conditions occurring in low grade metamorphic terranes. For this purpose, a special attention was addressed to the correlation between the Kübler-Index (KI) and vitrinite reflectance (VR). All these efforts are dedicated to estimate the P?CT conditions and thus to gain insight into the geodynamic evolution of low-grade metamorphic terranes. B. Kübler and M. Frey honored here concentrated their studies to the Helvetic Central Alps area. The very low-grade Helvetic domain is therefore of basic interest of this paper. Ensuing the extensive compilation of data from the Helvetic domain, a reinterpretation of Kübler and Frey??s research is presented in the light of last decade??s scientific progress. A comprehensive dataset available enables to discriminate many factors influencing the Kübler-Index and organic-matter reflectance alongside to time, temperature and pressure. The correlation is restricted to the KI and organic matter reflectance (mostly VR) because most of the studies used both methods. Organic matter reflectance (OMR) includes data from vitrinite reflectance and bituminite reflectance measurements. Geodynamics has important control on the KI/VR (OMR) correlation. Tectonic units having a similar geodynamic evolution are featured by the comparable KI/OMR trends, related to the particular paleo-geothermal conditions. Obviously the KI/OMR correlations provide a mean to characterise geothermal gradients and metamorphic very-low-grade pressure?Ctemperature conditions. In terranes where high deformations rates are reported, exceeding the high anchizone conditions, strain promotes the kinetic effects of temperature and pressure on the KI versus OMR ratio. 相似文献
57.
A model of household preparedness for earthquakes: how individuals make meaning of earthquake information and how this influences preparedness 总被引:4,自引:3,他引:1
One way to reduce the risk from earthquakes is for individuals to undertake preparations for earthquakes at home. Common preparation measures include gathering together survival items, undertaking mitigation actions, developing a household emergency plan, gaining survival skills or participating in wider social preparedness actions. While current earthquake education programmes advocate that people undertake a variety of these activities, actual household preparedness remains at modest levels. Effective earthquake education is inhibited by an incomplete understanding of how the preparedness process works. Previous research has focused on understanding the influence individual cognitive processes have on the earthquake preparedness process but has been limited in identifying other influences posed by the wider social contextual environment. This project used a symbolic interactionism perspective to explore the earthquake preparedness process through a series of qualitative interviews with householders in three New Zealand urban locations. It investigated earthquake information that individuals are exposed to, how people make meaning of this information and how this relates to undertaking actual preparedness measures. During the study, the relative influence of cognitive, emotive and societal factors on the preparedness process was explored and the interactions between these identified. A model of the preparedness process based on the interviews was developed and is presented in this paper. 相似文献
58.
A method for quantifying vulnerability, applied to the agricultural system of the Yaqui Valley, Mexico 总被引:13,自引:0,他引:13
Amy L. Luers David B. Lobell Leonard S. Sklar C. Lee Addams Pamela A. Matson 《Global Environmental Change》2003,13(4):255-267
We propose measuring vulnerability of selected outcome variables of concern (e.g. agricultural yield) to identified stressors (e.g. climate change) as a function of the state of the variables of concern relative to a threshold of damage, the sensitivity of the variables to the stressors, and the magnitude and frequency of the stressors to which the system is exposed. In addition, we provide a framework for assessing the extent adaptive capacity can reduce vulnerable conditions. We illustrate the utility of this approach by evaluating the vulnerability of wheat yields to climate change and market fluctuations in the Yaqui Valley, Mexico. 相似文献
59.
D.?JohnstonEmail author D.?Paton G.?L.?Crawford K.?Ronan B.?Houghton P.?Bürgelt 《Natural Hazards》2005,35(1):173-184
A survey of over 300 residents and visitors (non-residents) perceptions of tsunami hazards was carried out along the west coast of Washington State during August and September 2001. The study quantified respondents preparedness to deal with tsunami hazards. Despite success in disseminating hazard information, levels of preparedness were recorded at low to moderate levels. This finding is discussed in regard to the way in which people interpret hazard information and its implications for the process of adjustment adoption or preparedness. These data are also used to define strategies for enhancing preparedness. Strategies involve maintaining and enhancing hazard knowledge and risk perception, promoting the development of preparatory intentions, and facilitating the conversion of these intentions into sustained preparedness. A second phase of work began in February 2003, consisting of a series of focus groups which examined beliefs regarding preparedness and warnings, and a school survey. Preliminary findings of this work are presented. 相似文献
60.
We present observations of high frequency, intermediate degree, Ca-K line solar intensity oscillations. We compare the peak
frequencies determined from these 1991.4 observations with the peak frequencies from 1987.9 South Pole observations (Duvallet al., 1991) in that portion of the spatio-temporal diagram where the two datasets overlap (degrees between 30 and 150 and frequencies
between 4 and 6.6 mHz). We find that temporal changes are detectable in the high frequency spectrum and are particularly large
near 5.4 mHz. The m-averaged high frequency peaks decreased in frequency in 1991.4 compared to the peak frequencies measured
in 1987.9. The magnitude of the frequency shift is of the order of 10 μHz near 5.4 mHz, increases with degree, and decreases to near zero both above and below 5.4 mHz. It is unlikely that these temporal
changes in the high frequency spectrum are due to a change in the height of the subphotospheric acoustic source layer. A physical
mechanism for these frequency shifts has not yet been identified. 相似文献