The dynamics and temperature regime of the crater lakes in the Nevado de Toluca volcano, Mexico

Abstract

Volcanic lakes are unique ecosystems with complex relationships between atmospheric variables and crater lake dynamics. In two adjacent tropical, high mountain lakes, spectral analysis of coupled in situ meteorological and hydrodynamic measurements revealed strong diurnal fluctuations in water temperature due to wind-forced internal gravity waves and free seiche oscillations. Although the amplitudes of these internal motions were small, they contribute to the transfer of momentum and mixing, with large potential impacts on lake productivity. During daytime heating, in both lakes, a thermocline formed in the near-surface layer (2−3 m depth) but eroded at night. The heat penetration into each lake within the crater differed significantly, even though they were ∼ 500 m apart, driven by differences in water transparency and algal growth. Analyses of coupling between local meteorology and lake hydrodynamics revealed complex forcing of small-scale patterns which are important to incorporate into future studies to understand how ecosystem productivity is modulated.