Day 10: Successful firn air pumping day – until the last hour

Today was overall a good day for the firn air sampling team. But it ended with a bad surprise (see below)

The drilling was very successful, and we managed to drill to and sample air from 3 layers (23, 28 and 33 meters depth). It was a long day as well (started at 7 am, now it is 11 pm), so will only give some quick impressions: Here you see me at the firn hole lowering the sampling tubes into the hole.

We have now completed 7 sampling depths, and the setup has been improved over the days so that in principle it works well in the present situation (in a tent on the ice sheet). Below you see some examples of the different canisters that we fill:

1. low-pressure metal cans (we fill them for four different institutes from France, Denmark, England and our institute, and low pressure means an over pressure of 2 atmospheres)
2. glass flasks (we fill them for three different institutes from Japan, France and Korea)
3. high pressure cylinders (we will them for an institute in Switzerland and for our own lab)

We were going back and forth to the firn camp in relatively nice weather a lot, so we were a lot on the snow mobiles. Here you see a photo of Johannes driving and Kevin and Camilla on the sled.

But when we were collecting the very last air sample, I noticed that it took very long. This is a clear indication of a problem, so I checked for a leak with soap and found a “beautiful” leak.

The bubbles below the pressure gauge on our compressor show a very big leak….

Unfortunately a very big one, on the high pressure side of our compressor. So we had to stop the sampling and fix it. This worked, but afterwards we detected still two smaller leaks which are at positions where it is not so easy to fix, and there is a danger that we destroy more than we fix, so we decided to continue the sampling with the slightly leaking compressor and then finished the camp for the night (at -24 ºC). Hopefully we have a good idea tomorrow.