Artículos de conferencia

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Browsing Artículos de conferencia by browse.metadata.categoriaods "13 Acción por el clima"

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    Application of MM5/CALMET/CAMx in Santiago, Chile
    (2003) Jorquera, Héctor; Castro, Julio; Escobar, Jaime; Jakobs, Hermann
    The Comprehensive Air Quality Model with Extensions (CAMx) has been applied to two summer photochemical episodes in the greater metro area of Santiago, Chile. It is shown that the CAMx model predicts reasonably well the spatial gradients of gaseous pollutants and the weekly cycle of variation for CO and NOx. The emission estimates for CO seem to be quite on agreement with actual emissions in 2000. NOx emissions are more appropriate for the 1998 scenario, whereas for 2000 they seem to overestimate actual emissions, so the mobile sources emission factors need to be verified. The SO2 simulations indicate that there relevant sources not accounted for in the inventory. There are problems with the VOC emissions for the area sources, because the model predictions for ozone are quite below what is being observed, for all network stations in 1998, a scenario with reliable NOx simulated levels. For the 2000 scenario, this problem is worsened because of excessive ozone scavenging. When we use the results of a comprehensive VOC campaign to produce a synthetic VOC profile of emissions for the whole city, simulated ozone gets closer to ambient measurements for the 1998 scenario. For the 2000 scenario, the overestimation in the simulated NOx levels is large enough to prevent any significant ozone sensitivity with respect to VOC increases. All things considered, CAMx has passed the "proof of the concept" for studying photochemical episodes at Santiago, Chile. The major sources of uncertainty are the emission inventory estimates for NOx and VOC. As a second source of uncertainty, meteorology was not properly represented on the second half of the January 1998 episode, and there are some problems with the stations closer to the Andes foothills overnight, particularly regarding ozone nocturnal profiles, that deserve further research.
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    Strawberry crop in extreme climatic zones of Chilean Patagonia
    (INT SOC HORTICULTURAL SCIENCE, 2021) Gambardella, M.; Contreras, E.; Goma, C.; Grez, J.; Mezzetti, B; Battino, M; Baruzzi, G
    Chile is one of the main fresh fruit producing countries in the southern hemisphere; however, the strawberry (Fragaria x ananassa Duchesne ex Rozier) cultivation area is small compared to that of other fruit species (approximately 2,000 ha year(-1)). Strawberry production is concentrated in the central and south-central zones of the country. About one-third of the Chilean strawberry production is exported to other countries frozen (IQF, individual quick freezing), and the other two-thirds are destined to the local Chilean fresh market. This species is socially important, because it is a profitable alternative for small farmers. Due to the increase in temperatures and water supply problems in traditional areas in Chile, crops are moving to the south. The Aysen Region (Chilean Patagonia between 43 degrees 38' and 49 degrees 16'S) have an intricate geography, with climates ranging from cold rainy to cold windy steppes and eternal glaciers, which generate isolation by land. It is a region with large areas of protected parks and low population density (108,328 inhabitants in 108,494 km(2)). Traditional agricultural activity has been sheep farming, but diversification toward more profitable crops is necessary. In addition, food for the local population must be improved, because of limited access to fresh fruits and vegetables. In this context, strawberry production was recently introduced in the region. Sixteen experimental fields of 1,000 m(2) were established in three representative areas: humid, intermediate and microclimate zones. The best production conditions for strawberries and other berries were studied. Open field and tunnel cultivation were performed using wind curtains. In both cases, a technical and economically viable production was demonstrated with 'Albion', 'Monterrey' and 'Cristal'. Although the yield was very low (15 t ha(-1)), the high prices during late spring and in summer make the crop a very good alternative for this area. In the future, production and techniques will be improved and short-day cultivars will be introduced to concentrate and increase productivity.