Radiative equilibrium in Monte Carlo radiative transfer using frequency distribution adjustment

The Monte Carlo method is a powerful tool for performing radiative equilibrium calculations, even in complex geometries. The main drawback of the standard Monte Carlo radiative equilibrium methods is that they require iteration, which makes them numerically very demanding. Bjorkman & Wood recently proposed a frequency distribution adjustment scheme, which allows radiative equilibrium Monte Carlo calculations to be performed without iteration, by choosing the frequency of each re-emitted photon such that it corrects for the incorrect spectrum of the previously re-emitted photons. Although the method appears to yield correct results, we argue that its theoretical basis is not completely transparent, and that it is not completely clear whether this technique is an exact rigorous method, or whether it is just a good and convenient approximation. We critically study the general problem of how an already sampled distribution can be adjusted to a new distribution by adding data points sampled from an adjustment distribution. We show that this adjustment is not always possible, and that it depends on the shape of the original and desired distributions, as well as on the relative number of data points that can be added. Applying this theorem to radiative equilibrium Monte Carlo calculations, we provide a firm theoretical basis for the frequency distribution adjustment method of Bjorkman & Wood, and we demonstrate that this method provides the correct frequency distribution through the additional requirement of radiative equilibrium. We discuss the advantages and limitations of this approach, and show that it can easily be combined with the presence of additional heating sources and the concept of photon weighting. However, the method may fail if small dust grains are included... (abridged)Comment: 17 pages, 2 figures, accepted for publication in New Astronom

The Black Desert Drone Survey: New Perspectives on an Ancient Landscape

This paper presents the results of a large scale, drone-based aerial survey in northeastern Jordan. Drones have rapidly become one of the most cost-effective and efficient tools for collecting high-resolution landscape data, fitting between larger-scale, lower-resolution satellite data collection and the significantly more limited traditional terrestrial survey approaches. Drones are particularly effective in areas where anthropogenic features are visible on the surface but are too small to identify with commonly and economically available satellite data. Using imagery from fixed-wing and rotary-wing aircraft, along with photogrammetric processing, we surveyed an extensive archaeological landscape spanning 32 km2 at the site of Wadi al-Qattafi in the eastern badia region of Jordan, the largest archaeological drone survey, to date, in Jordan. The resulting data allowed us to map a wide range of anthropogenic features, including hunting traps, domestic structures, and tombs, as well as modern alterations to the landscape including road construction and looting pits. We documented thousands of previously unrecorded and largely unknown prehistoric structures, providing an improved understanding of major shifts in the prehistoric use of this landscape

Animal Management Strategies during the Chalcolithic in the Lower Galilee: New Data from Marj Rabba (Israel)

The Chalcolithic period in the Southern Levant witnessed increasing social differentiation and economic specialization. Some of the most important sources of economic specialization were animal products, particularly the secondary products of sheep, goats, and cattle. Also important, though neglected in the literature, were pigs. In this paper, we employ faunal data from the recently excavated site of Marj Rabba in the Lower Galilee. In particular, we investigate kill-off patterns, metrical data, and artifactual data. In order to distinguish between sheep and goats, we applied collagen fingerprinting (ZooMS) techniques to caprine teeth. We compare these data to other Chalcolithic sites in the Southern Levant in order to explore the regional differences in animal management strategies during this crucial period of socioeconomic change. In contrast to sites in the Northern Negev and Tulaylat al-Ghassul, animal management strategies at Marj Rabba were not aimed at specialization. Instead, they emphasized risk-minimization. Additionally, similar to sites in the northern Jordan River Valley, domestic pigs were an important resource. Finally, the cattle remains display numerous traction-related pathologies. These pathologies, coupled with the large proportion of sickle blades and the possible architectural remains of grain silos, suggest an emphasis on grain production. The difference between faunal patterns in the Northern Negev, Golan, Jordan River Valley, and Galilee regions points to a highly diverse animal economy in the Southern Levant during the Chalcolithic.Le Chalcolithique (4500-3600 cal. av. J.-C.) du Levant Sud est le foyer d’une différentiation sociale et d’une spécialisation économique accrue. Parmi les principales sources de spécialisation économique figurent les produits d’origine animale, particulièrement les produits dérivés des moutons, chèvres et bovins. Les suidés tiennent également une place importante, bien que négligée dans la littérature. Dans cet article, nous utilisons les informations relatives à la faune provenant du site de Marj Rabba en Basse Galilée. Nous étudions en particulier les courbes d’abattage, les données métriques, ainsi que les artefacts. Afin de distinguer les chèvres des moutons, nous avons analysé l’empreinte collagène (ZooMS) des dents de caprinés. Ces données sont comparées à celles d’autres sites chalcolithiques du Levant Sud afin d’explorer les différences régionales en termes de stratégies de gestion des troupeaux durant cette phase cruciale de changements socio-économiques. À l’inverse des sites du nord du Néguev et de Tulaylat al-Ghassul, les stratégies de gestion des troupeaux à Marj Rabba n’étaient pas destinées à la spécialisation. Elles mettent en revanche l’accent sur la minimisation des risques. De plus, comme dans la vallée septentrionale du Jourdain, les suidés constituaient une ressource importante. Enfin, les restes de bovidés de Marj Rabba montrent un nombre conséquent de pathologies liées à l’activité de traction. Cependant, les courbes d’abattage indiquent que les éleveurs n’ont pas cherché à différer l’âge d’abattage des bovins pour utiliser leur force de traction. Les pathologies suggèrent qu’on mettait en avant la production de grains. La différence entre la faune du nord du Néguev, du Golan, de la vallée du Jourdain et de la Galilée, met l’accent sur une économie des produits animaux extrêmement diversifiée dans le Levant Sud au cours du Chalcolithique.Price Max D., Buckley Mike, Kersel Morag M., Rowan Yorke M. Animal Management Strategies during the Chalcolithic in the Lower Galilee: New Data from Marj Rabba (Israel). In: Paléorient, 2013, vol. 39, n°2. pp. 183-200

Gazelles, Liminality, and Chalcolithic Ritual: A Case Study from Marj Rabba, Israel

Endangered today, gazelles were both economically and symbolically important to the peoples of the ancient Near East. In various contexts, the gazelle has represented liminality, death, and rebirth. Gazelles held special significance in the southern Levant, where archaeologists have documented cases, spanning 20,000 years, of ritual behavior involving gazelle body parts. What roles did gazelles play during the Chalcolithic (ca. 4500–3600 b.c.), a period of both decreased hunting and ritual intensification? In this article, we discuss a unique find of burned gazelle feet at the site of Marj Rabba (northern Israel). The feet were found within a well-constructed building that was used for rituals and included two articulated human feet. The gazelle foot bones, the majority of which derive from adult male mountain gazelles (Gazella gazella), appear to reflect the remains of intentionally destroyed skins or severed limbs. This unique find highlights the evolving symbolic importance of gazelles, perhaps as forces of liminality, in Chalcolithic rituals

Fodder, pasture, and the development of complex society in the Chalcolithic: isotopic perspectives on animal husbandry at Marj Rabba

The emergence of social complexity in the Southern Levant during the Chalcolithic (c. 4500–3600 cal. BC) was intimately tied to intensification in animal management. For the first time, secondary products such as milk and wool were intensively exploited, supplying communities with increasingly diverse foodstuffs and raw materials for craft production and exchange, but the precise herding practices underlying these new production strategies are unknown. Here, we explore the role of multi-species livestock pasturing through carbon and nitrogen isotopic analysis of animal bones from Marj Rabba (Har Hasha’avi, West) in the Lower Galilee (ca. 4600–4200 cal. BC). Isotopic results suggest different pasturing/foddering of sheep compared with goats. Cattle were largely pastured locally, but high δ13C values in some animals indicate access to the Jordan River Valley (the Ghor in Arabic), where major Chalcolithic settlements were situated. This may indicate some cattle were moved along regional Chalcolithic exchange networks established for other prestige objects, such as copper. Finally, we provide evidence for moderate 15N enrichment in pigs relative to herbivorous livestock indicates. Possible interpretations include consumption of nuts (esp. acorns), household refuse containing animal protein, and/or fattening pigs on grain. Although an interpretation that requires further exploration, grain foddering of pigs would complement the zooarchaeological data for early slaughter, which suggests intensive meat production at Marj Rabba. It might also help explain why pig husbandry, as a drain on grain stockpiles, was gradually abandoned during the Bronze Age. Taken together, the isotopic and zooarchaeological data indicate an economy in transition from a non-specialized, household-based Neolithic economy to one in which the production of agrarian wealth, including animal secondary products, was beginning to emerge