Strong Down-Valley Low-Level Jets over the Atacama Desert: Observational Characterization

The near-surface wind and temperature regime at three points in the Atacama Desert of northern Chile is described using two-year multi-level measurements from 80-m towers located in an altitude range between 2100 and 2700 m ASL. The data reveal the frequent development of strong nocturnal drainage flows at all sites. Down-valley nose-shaped wind speed profiles are observed with maximum values occurring at heights between 20 m and 60 m AGL. The flow intensity shows considerable inter-daily variability and a seasonal modulation of maximum speeds, which in the cold season can attain hourly average values larger than 20 m s−1. Turbulent mixing appears significant over the full tower layer, affecting the curvature of the nighttime temperature profile and possibly explaining the observed increase of surface temperatures in the down-valley direction. Nocturnal valley winds and temperatures are weakly controlled by upper-air conditions observed at the nearest aerological station. Estimates of terms in the momentum budget for the development and the quasi-stationary phases of the down-valley flows suggest that the pressure gradient force due to the near-surface cooling along the sloping valley axes plays an important role in these drainage flows. A scale for the jet nose height of equilibrium turbulent down-slope jets is proposed, based on surface friction velocity and surface inversion intensity. At one of the sites this scale explains about 70% of the case-to-case observed variance of jet nose heights. Further modeling and observational work is needed, however, in order to better define the dynamics, extent and turbulence structure of this flow system, which has significant wind-energy, climatic and environmental implications.

Saberes locales: un aporte clave para el desarrollo sustentable de la región andina

Los saberes locales son de suma importancia tanto para el desarrollo humano sustentable como para la conservación ambiental. En los Andes, la vida de las poblaciones locales depende en gran medida de sus saberes. Estos saberes son vigentes y dinámicos, y responden a los cambios socioeconómicos y ambientales mediante un proceso de resistencia cultural y de adaptación. Sin embargo también son vulnerables y, consiguientemente, es importante apoyar su fortalecimiento. Los saberes locales deben ser integrados efectivamente en los proyectos de desarrollo. De hecho, un diálogo entre los saberes locales y los denominados “científicos” permite dar paso a soluciones novedosas a los nuevos retos socioambientales que enfrentan las comunidades andinas en un mundo globalizado.

Archaeological silence and ecorefuges: arid events in the Puna of Atacama during the Middle Holocene

This paper briefly summarizes presearch concerning the mid-Holocene in the western slope of the puna de Atacama (20–25°S). Proxy data and dates from palynological, limnological, geomorphological archives were compared with data recovered from the archaeological sites in high altitude basins, intermediate ravines and piemontane paleowetlands. Due to exceptionally favorable conditions, numerous Early Holocene archaeological sites were found. In contrast, the lack of occupations in previously populated areas suggests a decline in human activity during the arid mid-Holocene. In this context, two key concepts are introduced: ecorefuge or ecological refuge, and archaeological silence (silencio arqueológico). The first refers to the particular favorable locations occupied by human groups during the mid-Holocene. The second provides a better understanding about the impact of the arid interval during this period on human adaptations in the most barren territories of the New World.

Culturas políticas en la región andina

La región andina se caracteriza, en el nuevo milenio, por transformaciones radicales de sus culturas políticas. Los movimientos indígenas de Ecuador y Bolivia son paradigmáticos de un proceso de descolonización cultural que rompió con los esquemas poscoloniales de representación política. Junto a ello, se observa una ruptura con las políticas neoliberales que se expresa en una nueva izquierda latinoamericana asociada a nombres como Hugo Chávez, Evo Morales y Rafael Correa. El presente volumen reúne dieciocho contribuciones que analizan dichos cambios en las culturas políticas desde diversas perspectivas académicas. De este modo, Culturas políticas en la región andina constituye un aporte hacia un mayor entendimiento de un espacio político que está en movimiento.