Working with Donna

Joined: 23 Mar 2004 Posts: 72

Yesterday was probably the coldest day and night since I have been here. I think at nighttime, the temperature dropped to somewhere in the –30s. You can see from this photo that it was a bit chilly!!

Today I spent the day with Donna. She is working with the University of Arizona. Her part of the project involves detecting how much hydrogen peroxide (H2O2) , methyl hydrogen peroxide (MHP) and formaldehyde (HCHO) are being formed in the snow. These chemicals are formed when hydroxyl (OH) breaks apart chemicals like nitric acid (HNO3) get deposited in the snow.

Her machines work much in the same way that the other researchers do. They collect air samples from the firn (snow pack) and from the ambient (air). Those air samples are mixed with water and sent through a column that separates the gases, so they can be monitored as to how much of each is there.

Unfortunately, Donna’s system is much more sensitive than most of the others. Today when we went to check to make sure samples were being collected and read correctly, Donna noticed that all was not well (and no, I did NOT break it)!! She spent a great part of the morning troubleshooting. As you can see, there are many tiny tubes bringing chemicals through the system. Two of the tubes, through much investigation, were found to be cracked. It took most of the morning to get the machine up and running.

When we finished that, we had to collect snow samples, so that the chemicals mentioned above could be measured directly out of the snow instead of the air. We had to take a sample from every 5cm from the surface to 20 cm.

Testing these samples is a very tedious process. The machine works in the same way, except that the snow samples need to be added manually.

First, we needed to find the density of the snow. Then we needed to run the samples through the machine. It takes about two minutes to run each sample, and after about 25 samples, we needed to check the baseline. That means that we needed to make sure that the number we started with when we ran just purified water was still the same.

This took almost all day to do. We had 168 samples to run!

These samples were not only from the ones we took today, but there were samples from the 2 meter pit that was dug last night.

Tonight was a very exciting night for me----I GOT TO TAKE A SHOWER!!!!!!!
Also, it turned out to be a beautiful night- check out this picture of the sun!!