Abstract

MAENZA, Reinaldo A  and  COMPAGNUCCI, Rosa H. Simulación de la pequeña edad de hielo usando el modelo EdGCM. Geoacta [online]. 2010, vol.35, n.2, pp.78-90. ISSN 1852-7744.

The Little Ice Age (LIA) was a cold period that ranged from taken part of the century XIV until taken part of the century XIX. In the period occurred three pulses of minimum values of temperature and will study the second of them comprised between 1645-1715 designated Maunder Minimum (MM). The decrease of the solar activity, the increase of the volcanic activity and the change in the Carbon Dioxide concentrations were the main forcings during these periods. In present work we realize distinct simulations of the climatic conditions for the South Hemisphere, by means of the General Circulation Model EdGCM, with the end to obtain stages of answer to the changes of irradiance and CO2 for the MM. At the same time, the climatic differences between years of maxima and minimum values of sunshine during the century XX determined by means of the results of the re-analysis of the NCEP/NCAR, compare with the differences between the current conditions and the ones of the MM, simulated by the model. The anomalies between the XX century and the MM obtained with the EdGCM are in agree qualitatively, and also quantitatively in some locations, with the proxy data information for various regions of the Hemisphere South. The annual temperature anomalies, between the MM and the 20th century ending conditions, are negative for both hemispheres and the temperature anomalies result more intense on semester November-April. Furthermore, over South America, shows a more intense centre in subtropical latitude and central and south Patagonia. The cold pattern obtained by the model is in agreement, on magnitude too, with proxy information obtained in some South America regions. The westerly wind component undergoes a shift to lower latitudes during the MM. The atmospheric circulation anomalies obtained in the simulations, show a pattern, over middle and high latitudes, where alternate three or four positive and negative anomaly centres, which is in agreement with a greater meridional component of the flux. Both patterns are similar to those present during El Niño events.

Keywords : Maunder Minimum; Paleoclimate; EdGCM model simulations; Irradiance; Carbon Dioxide.

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