Studying Microclimate in Central Chile

For map geeks, especially geographers and cartographers, it might be of interest to know about an overlooked peculiarity in Chilean maps. Unlike other countries, perhaps with the exception of Argentina, topographic and nautical charts use the words “glaciar” and “ventisquero” to refer to a glacier or zone filled with perennial snow (see an example for the San Quintín glacier, Chilean Patagonia, here).

There are limited references on the web about why “ventisquero” is utilized in these maps, although Wikipedia suggests that this word is utilized in Spain to denote locations where snow accumulates by snowdrift (maybe an inheritance from the conquistadors’ comprehension of snow and ice at the time?). As a “rookie” undergrad glaciologist in my early twenties (around the year 2000), this inconsistency caught my attention during my visit to a glacier in Monte Tronador. Without any background knowledge at that time, I assimilated the word “ventisquero” as meaning that glaciers or perennial snow produce wind (one meaning of ventisquero is “that brings gale”).

Cotón Glacier from the location of the highest weather station installed (Source: Felipe Fernández).

A few years later, I convinced myself of the existence of this glacier/snow wind when I visited the Pío XI glacier. I experienced a lot of turbulence when passing above the ablation zone by helicopter. Misleading or not, understanding the wind system over glaciers and snow remained on my mind.

Thanks to a research grant from the Chilean Council of Sciences (CONICYT) and support from the National Forest Corporation (CONAF), this last year we began a research project to study the features of the atmospheric boundary layer above glaciers and snow, where we expect to provide better understanding of several microclimatic features, including the glacier wind, especially in a regional scenario of less snow and increasing glacier melt and recession. In this research, we combine several methods: climatic observations, numerical climate modeling, and surveys using unmanned aerial vehicles.

The research team with mules, horses, and “arrieros” (horsemen) carrying the instruments and mountain gear (Source: Felipe Fernández).

On March 2017, we carried out our first field campaign to install weather stations in the forefield of the Cipreses and Cotón glaciers, two relatively large ice bodies that feed the Cachapoal river in Central Chile, which in turn power a great share of the Chilean wine industry. Our goal with these observations is to capture any change in near-surface weather conditions when seasonal snow covers the surface.

Installing stations on the forefield of the glaciers (Source: Felipe Fernández).

Our campaign began when we drove nearly seven hours from Concepción to the park entrance. We spent the next two days on a 25-km walk (~15 miles) to get to the upper-valley.  Because March corresponds to the end of the summer, we were hit by intense sunshine and temperatures above 30°C (86 F), which slowed us down. Thus, after two days and two river crossings, helped by “arrieros,” horses and mules, we began the installation of the stations, configured to continuously measure near-surface temperature, relative humidity, incoming and outgoing solar radiation (so we get albedo), atmospheric pressure, and wind speed and direction.

Hiking toward the location of the highest weather station installed during the fieldtrip (Source: Marcos Gómez).

In all locations, we tried to follow the main axis of the valley, but in one of the cases we had to go closer to the valley wall because the valley gets too narrow. There, we also realized that the Cipreses Glacier had receded quite a lot and was now above a nearly 500-m rock wall.

After three days, we left the upper valley hoping the stations will be functioning and recording when we return next October. In the meantime, we expect to find further funding to reach the highest sections of the valley using a helicopter and install climatic sensors on the glacier.

The research team at base camp (Source: Felipe Fernández).

The team exhibited a great mood and scientific curiosity, including members Mauricio Aleuy, a B.S. in geography who is working on snow/glacier mapping in the study area; Juan Varas, a B.S. in geography who is studying recent thickness changes in the glaciers of this region using DEMs; Marcos Gómez, a professional geographer and mountaineer who was in charge of mountain safety and logistics; and Felipe Fernández, a photographer and filmmaker who recorded the team’s activities.

Alfonso Fernández is associate professor of physical geography at the Universidad de Concepción, Chile.