Dynamic response to valley breeze circulation in Santa María del Oro, a volcanic lake in Mexico

Abstract

The paper discusses the dynamic response to valley breeze circulation in Santa Maria del Oro, a volcanic lake in Mexico. Hourly records of wind measurements were used to construct a hydrodynamical model of the level fluctuations of the lake's water as well as integrated drift currents. The calculations show that the valley breeze circulation stimulates barotropic seiches in the lake with a period of 2.6 minutes and maximal level in the southwest part up to 18 mm. The drift current form two circulating rings having an opposite directions: anticyclonical in northern part of the lake and cyclonical in the southern. At the external edge of these rings the current speed can reach 20 cm/s. The measurements have shown that most part of the year the lake is strongly stratified. The maximal vertical temperature gradients are over 1°C/m in November and August, in a layer of 17–20 m.