Using air filters to see what aerosols are made of

Hello together. My Name is Denis Leppla and I am working at ATTO since 2017 with rather simple instruments for filter sampling. It consists of a filter holder to collect aerosol particles from the air on a certain other filter material. For that, it also needs a pump to pass air through the filter.  We then store the filters in a freezer until we bring them back to Germany. There we analyze them with a mass spectrometer at the Max Planck Institute for Chemistry in Mainz. With this analysis, we can get insights into the chemical composition of aerosol particles and identify hundreds of different compounds. They are responsible for the earth’s climate. Depending on their chemical and physical properties they can serve as cloud condensation nuclei or scatter or absorb sunlight.

We have installed three of these sampling filters at different heights on the tall tower (also on 325 m) to measure vertical profiles. The only problem with them is the pump. They are not made to operate in the rainforest exposed to the elements. Either it’s too humid or it’s too hot. So every time I take a look at the instruments it is a bit of a gamble if the pumps are still running. But in general, it is a pretty carefree setup and I can focus on surviving in the jungle. The pumps run for several hours to collect enough aerosol mass on the filter. After that, I have to replace the filter with a new one. As you can imagine, I need to do this manually and climb on top of the tower – twice every day that I am at ATTO.

Since I replace the filters in the early morning and the late afternoon, I have the chance to enjoy sunset and sunrise at the most stunning place I have ever been, 325 m above the rainforest. Even though this is getting really exhausting after three weeks in the jungle, there is nothing more satisfying than to reach the top (in a decent time) and to be rewarded with this amazing view. And on top of that, you get in pretty good shape for the next holidays at the beach. That’s reasons enough for me to go without the new elevator ;).

Denis with him sampling filter
sunset at ATTO
© Denis Leppla