Cloudiness climatology in north-central Argentina and its relation with the thermal field

The effect of cloud cover in forming a significant barrier to the penetration of solar radiation and its role in reducing the daily range by preventing high maxima by day and low minima by night is well known. Nevertheless, cloudiness climatology and its relation with minimum, maximum and mean temperatures is not yet accurately known in many regions. In this study, we analyzed the total cloud cover annual cycle in the Argentine sector north of 40°S and its relation with the thermal field. Hourly total cloudiness and daily temperature data are analyzed at 20 stations for the period 1959-90. Correlation maps between total cloud cover and temperature show different areas where the relation is stronger. For example, in central/east Argentina monthly correlation between total cloud cover at 08.00 LT and minimum temperature is positive for every month but significant in statistical terms only during the cold period (April-October). In the case of the correlation between total cloud cover at 14.00 LT and maximum temperatures, the relation is inverse for almost every month, but the most significant correlations are found during the summer months.

As in a previous study, it was found a general warming in the analyzed region during the 80s, we also explore if this warming could be related to changes in total cloud cover during that decade in comparison to the previous ones.