ABSTRACT
Parameters such as precipitation in the central region of Chile and the annual flow of the Argentine cordilleran rivers are sensitive to the fluctuations of the permanent subtropical Pacific anticyclone latitudinal position. Recent climatological studies have led to obtain temporal parameters related to the position, form and air circulation around this center of high pressure.
22 available chronologies of tree-rings along the Andean Cordillera from lat. 32° to 43° S, have been employed with the aim of establishing the variation in the latitudinal position of the Pacific anticyclone. These chronologies were developed from Austrocedrus chilensis (D.Don) Flor et. Boutl., Araucaria araucana (Mol.) Koch., Fitzroya cupressoides (Mol.) Johnst. and Nothofagus pumilio (Poepp. et Endl.) Krasser.
The annual variation in the width of growth tree-rings were correlated with the monthly average latitudinal position of the anticyclone (LSA) and with two indexes of circulation exclusively related with the anticyclone behaviour, the Austral Zonal Circulation Index (ICZA) and the Central Zonal Circulation Index (ICZC).
The results obtained remarked that the chronologies on Austrocedrus chilensis, from the central region of Chile and those on Araucaria araucana coming from Neuguén, Argentina, show growth variation strongly associated to the interannual fluctuations in the anticyclon position. The latitudinal position of the subtropical Pacific anticyclone is discussed based on these relationships.
