Gondola-sonde @ Stubai

As part of the InnSAR Summer School on Alpine Research, which is this year on Surface-Atmosphere Exchange in Mountainous Terrain, we took the students to Stubai glacier to have a look at some real conditions in complex glaciated terrain. Although we were unlucky with the weather as the scheduled field trip day was cloudy and windless, we nevertheless had a good time, going into the artificial ice cave that has been dug into the glacier there and we also did some small demonstration experiments and measurements on the glacier surface.

I have a few Kestrel weather meters, which are hand-held weather stations designed for mountaineers, sailers, paraglider and the like. In comparison with scientific weather stations I have found them to perform well, and consequently use them for appropriate scientific application as well.

At the suggestion of Prof. John Pomeroy I attempted my first Gondola-sonde (nomenclature credit also belongs to John!). So whats that then? It means that I stuck my hand out of the gondola window with the Kestrel to see if we could observe the temperature change with elevation this way. I have to apologise here that unfortunately I did not calibrate the instrument to the true elevation so the elevations given are based on the uncalibrated elevation computed from the barometric pressure using the standard atmosphere profile. As a result the elevations recorded at the 4 gondola stations differ from their stated elevations by between 98 and 168m. This could certainly have been improved had I calibrated the instrument.

The figure below shows a scatter plot of the recorded air temperature against uncalibrated elevations as we went up and down the top lift section, and then all the way back down to the valley. For reference, the stated elevations of the gondola stations taken from the Stubai Gletscher interactive lift map (where you can also see the layout of the stations) are: Schaufeljoch (3170m); Eisgrat (2887m); Mittelstation (2293m) and Mutterbergalm (1754m).

Gondolasonde

Given that (a) I did not calibrate the elevation, and (b) the height of the gondola above the ground changes over the course of the lift the values do not look too unreasonable. As you can see from the ascent and descent of the top lift section, which passes over the glacier, the measurements on the way up were not repeatable on the way down, and indeed on the descent the data collected do not appear to make much sense at all. I’m not sure why this would be, but I am showing the data here anyway to demonstrate that things are not always simple. The measurements were made out of different sides of the gondola, on the way up my arm was stuck out of the window on the west side and on the way down on the east side. No other windows were open, but it is possible, as suggested by one of the students, that warm air was spilling out of the gondola cabin.

About lindsey

Environmental scientist. I am glaciologist specialising in glacier-climate interactions to better understand the climate system. The point of this is to understand how glaciated envionments might change in the future - how the glaciers will respond and what the impact on associated water resources and hazard potential will be.
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