Qatar Islamic Archaeology and Heritage Project: End of Season Report : 2011-2012

International audienc

Problematising the shifting capitals of medieval Arran: from Bardhaʿa to Janza in the 10th-12th centuries

The dominant historical narrative for early Islamic frontier zones such as Arran, in the Caucasus, tends to focus on the administrative centres, the capital cities. As this story of development becomes synthesised and simplified, there has been a tendency to understand this process as the decline of one major centre and the rise of another, almost in the sense of city-states. This paper reconsiders the case of the changing capitals of Arran, to understand how urbanism developed in the Caucasus in the early Islamic period and how this gave rise to the situation as observed in the tenth–twelfth century when the region is essentially independent from the core Islamic lands, albeit regularly a vassal state. In doing so, new archaeological evidence is combined with that from existing historical sources, to propose a new model for the urban settlement patterns of the medieval period in the southeastern Caucasus

Advance telephone calls ahead of reminder questionnaires increase response rate in non-responders compared to questionnaire reminders only: The RECORD phone trial

Peer reviewe

The dynamics of Baroclinic Zonal jets

Multiple alternating zonal jets are a ubiquitous feature of planetary atmospheres and oceans. However, most studies to date have focused on the special case of barotropic jets. Here, the dynamics of freely evolving baroclinic jets are investigated using a two-layer quasigeostrophic annulus model with sloping topography. In a suite of 15 numerical simulations, the baroclinic Rossby radius and baroclinic Rhines scale are sampled by varying the stratification and root-mean-square eddy velocity, respectively. Small-scale eddies in the initial state evolve through geostrophic turbulence and accelerate zonally as they grow in horizontal scale, first isotropically and then anisotropically. This process leads ultimately to the formation of jets, which take about 2500 rotation periods to equilibrate. The kinetic energy spectrum of the equilibrated baroclinic zonal flow steepens from a −3 power law at small scales to a −5 power law near the jet scale. The conditions most favorable for producing multiple alternating baroclinic jets are large baroclinic Rossby radius (i.e., strong stratification) and small baroclinic Rhines scale (i.e., weak root-mean-square eddy velocity). The baroclinic jet width is diagnosed objectively and found to be 2.2–2.8 times larger than the baroclinic Rhines scale, with a best estimate of 2.5 times larger. This finding suggests that Rossby wave motions must be moving at speeds of approximately 6 times the turbulent eddy velocity in order to be capable of arresting the isotropic inverse energy cascade

Semi-fortified Palatial Complexes in Central Asia: New Work at the Great Kyz Kala, Merv, Turkmenistan

Within Central Asia there is an unusual group of earthen buildings (köshks), usually constructed on raised platforms, with vertical engaged columns forming iconic ‘corrugations’ on the exterior walls. The complexes are semi-fortified, with a second storey entrance, and often with asymmetrical ranges of rooms around an internal courtyard. Little systematic archaeological work has taken place on these monuments, which have mainly been studied as relatively eroded standing structures. However, recent work at the Great Kyz Kala at Merv, Turkmenistan, the largest surviving monumental köshk in Central Asia, has provided more details of construction and use. The excavations suggest that this complex was constructed in the 8th/9th century CE, with well-appointed rooms on the second storey, including a large hall, and functional rooms and storage spaces around a courtyard on the lower floor. The complex was set within an enclosure, containing gardens and possibly ancillary buildings. This particular köshk may have acted as an elite palatial suburban residence, perhaps for the governor of Merv.Ambassador's Fund for Cultural Preservatio

The Need for Laboratory Measurements and Ab Initio Studies to Aid Understanding of Exoplanetary Atmospheres

We are now on a clear trajectory for improvements in exoplanet observations that will revolutionize our ability to characterize their atmospheric structure, composition, and circulation, from gas giants to rocky planets. However, exoplanet atmospheric models capable of interpreting the upcoming observations are often limited by insufficiencies in the laboratory and theoretical data that serve as critical inputs to atmospheric physical and chemical tools. Here we provide an up-to-date and condensed description of areas where laboratory and/or ab initio investigations could fill critical gaps in our ability to model exoplanet atmospheric opacities, clouds, and chemistry, building off a larger 2016 white paper, and endorsed by the NAS Exoplanet Science Strategy report. Now is the ideal time for progress in these areas, but this progress requires better access to, understanding of, and training in the production of spectroscopic data as well as a better insight into chemical reaction kinetics both thermal and radiation-induced at a broad range of temperatures. Given that most published efforts have emphasized relatively Earth-like conditions, we can expect significant and enlightening discoveries as emphasis moves to the exotic atmospheres of exoplanets.Comment: Submitted as an Astro2020 Science White Pape