Gabriel Freitas

About me

I’m a physicist specialized in radiation. Within environmental sciences, my main topic of interest is aerosols and their interaction with clouds. One particular type of aerosol is bioaerosols, which are the ones emitted from biological entities. Examples of such particles are bacteria and pollen. In aerosol-terms, bioaerosol are large and have a rough surface. These qualities render bioaerosols as efficient ice nucleating particles. That is, they facilitate the formation of ice at higher temperatures. Within a cloud, the presence of ice can affect its lifetime and radiative properties. Thus, the presence of bioaerosols can be of significant climate importance, specially over pristine environments. However, sampling, identifying and quantifying bioaerosols presence and emissions is a difficult task.

My research here at Stockholm University revolves around using a novel single particle instrument, the Multiparameter Bioaerosol Spectrometer (MBS), to measure bioaerosols over different environments. The MBS retrieves information on the size, morphology and composition of each individual particles by applying state-of-the-art laser-induced elastic light scattering and fluorescence spectroscopy techniques. We have used the MBS on several different field campaigns to unravel the presence of bioaerosols. A mention can be made to our 1.5 year campaign in Ny-Ålesund, Svalbard, where the MBS measured bioaerosols in the Arctic and within clouds. This work is the core of my PhD thesis entitled “Bioaerosols and their importance for Arctic clouds”.

You will find further information on projects/campaigns I’m currently working on below.