Surface Energy Balance model for high-altitude glacial system at 19°N on Glaciar Norte, Mexico

Abstract

The glaciers of Mexico are very small ice bodies located on top of the highest mountains of Mexico. They represent a natural gauge for the climatic changes at the 19°N latitude where no other ice bodies are located around the world. Glaciar Norte glacier on Citlaltépetl Volcano, Mexico, has been retreating in a huge scale, just like other glaciers close to the tropics. Following the current trend of the small glaciers around the world, this glacier will probably disappear before mid-century and with its disappearance an important climatic gauge at this latitude will be gone. Therefore, it is important to identify the factors influencing the retreat and eventual demise of the glaciers. This study focuses on the analysis of the energy fluxes of Glaciar Norte's surface on the northern flank of Citlaltépetl Volcano, Mexico. From this, it was calculated the energy balance for a single point on the glacier surface. Here, the glacio-meteorological study is described using data from automatic weather stations installed at >5100 masl with the energy balance model developed from this data. The results suggest that net radiation is the main component responsible for the retreat of Mexican glaciers since this parameter controls the energy balance variability. This situation was compared to the energy balance regime present on other tropical and mid-latitude glaciers and it was possible to establish a first approximation of the energy balance regime on glaciers near 19N latitude based on energy balance variability.