Association between Tucuman Temperature and the Solar Cycle Length

One of the longest time series record of temperature in Argentina has been used, covering the period 1889-1998. These data belong to San Miguel de Tucuman, which is located 26º 48’ S, 65º 12’ W, and 481 m above sea level. In this work, Tucuman temperature anomaly (TTA) that is the deviations from the mean, has been considered.

The solar cycle length (SCL) varies with solar activity in such a way that high activity implies short solar cycles while long solar cycles correspond to low activity levels. SCL is a parameter of a long term variation which has a periodicity of approximately 88 years.

In order to determine the association between the TTA and SCL, the mean TTA value for each solar cycle has been estimated and SCL has been smoothed with the Gleissberg filter.

A good agreement between SCL and TTA time behavior is observed. There is a close association between these curves even in the important decrease from 1945 to 1970, where it should be expected a temperature increase responding to an increasing greenhouse effect, due to antrhopogenic reasons. Instead, TTA closely follows the SCL variation in its downward trend.