This study analyzed and discussed the instrumental measurements of temperature and currents made on January 10, 2007,
High-mountain lakes are unique ecosystems with very few examples at tropical latitudes for experimentation. A two-year, high-frequency meteorological and water-column dataset from the crater of the Nevado de Toluca volcano, in Mexico, at an altitude of about 4200 m above sea level, allowed for the study of temporal changes in the thermal structure, water level, and water balance in the Lakes El Sol and La Luna, separated by about 500 m by a lava dome. Annual fluctuations in the water level of the lakes and calculations of the annual variability of the water balance showed that the lakes accumulated almost four times less water from rainfall than expected. Furthermore, the temperature measured at a depth of 15 cm in the bottom sediments of Lake El Sol revealed an unexpected warming during the cold season. Estimated heat fluxes through the lake bottom were less than 0.3 W m−2 during the winter and less than 0.1 W m−2 during the rest of the year. Although the variability of the hydrometeorological regime of high-mountain lakes remains relatively poorly understood, our results significantly improve the understanding of these complex processes of stratification and mixing in these unique lake ecosystems.
Measurements of temperature, currents and lake level taken in 2005-2014 are analyzed and discussed. Moored measurements of temperature and level in the northern part of the lake reveal the presence of seiches oscillations of the first and second modes, with periods of 5.7 and 2.8 hours, and amplitudes of 15.4 and 2.1 mm. In 2006 four temperature cross-sections were carried out in the study area. The obtained data reveal that in all four seasons of the year the temperatures averaged over the north and south coastal areas differ by 2-3°C. The lake currents were simulated using the HAMSOM 2-D hydrodynamic model both for wet and dry seasons. The model results are in good agreement with the ADCP data. The presence of an anticyclonic gyre, 10-12 km in diameter, in the central part of the lake in both seasons is revealed. In particular, the summer 2014 data provide evidence of the gyre and its impact on the spatial distribution of temperature in the lake.
Classical numerical solutions of the Navier-Stokes equations applied to Coastal Ocean Modeling are based on the Finite Volume Method and the Finite Element Method. The Finite Volume Method guarantees local and global mass conservation. A property not satisfied by the Finite Volume Method. On the down side, the Finite Volume Method requires non trivial modifications to attain high order approximations unlike the Finite Volume Method. It has been contended that the Discontinuous Galerkin Method, locally conservative and high order, is a natural progression for Coastal Ocean Modeling. Consequently, as a primer we consider the vertical ocean-slice model with the inclusion of density effects. To solve these non steady Partial Differential Equations, we develop a pressure projection method for solution. We propose a Hybridized Discontinuous Galerkin solution for the required Poisson Problem in each time step. The purpose, is to reduce the computational cost of classical applications of the Discontinuous Galerkin method. The Hybridized Discontinuous Galerkin method is first presented as a general elliptic problem solver. It is shown that a high order implementation yields fast and accurate approximations on coarse meshes.
In situ coastal oceanographic and meteorological data were collected on the Mexican Tropical Pacific coast near Barra de Navidad, Jalisco, Mexico during September 2001 from before and after the passing of Hurricane Juliette. When the leading and trailing edges of the hurricane passed through the study area, wind speeds reached 15 m s-1 and caused a significant deepening of the thermocline, mixing of the upper 40 m of the water column, and a rise in sea level of almost 50 cm at the coast, with effects lasting for about 5 days. A decrease in temperature and an increase in salinity occurred in the upper 20 m, with the opposite occurring below 20 m. Although analyses of open ocean responses to hurricanes are widely available from satellite data, in situ coastal water-column and sea-level data are difficult to acquire, yet crucial to inform coastal flooding models and risk assessment studies. This short data set provides a rare opportunity to explore in situ hurricane effects on this understudied coast.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.