Reactivit'Air

An important part of my Academy Research Fellow project (2017-2022) funded by Academy of Finland was the development of an instrument to measure total ozone (O3) reactivity. The paper describing the method we use, based on an idea by Dr. Detlev Helmig, and developed together with his group, has just been published in Atmospheric Measurement Techniques . At the time of my proposal submission in 2016, there had been only one publication on the topic of total O3 reactivity measurement by Prof. Jun Matsumoto (Waseda University, Tokyo, Japan). I was also aware of measurements that had been done by Dr. Helmig's group that had been presented at conferences. This is why I visited Prof. Matsumoto in Tokyo in December 2017 and then went to Boulder CO, U.S.A. , with Anssi Liikanen , in January 2018. Anssi stayed almost two months to work in Dr. Helmig's laboratory, performing many tests on the total O3 reactivity monitor (TORM).   Figure 1. Left: TORM at the Toolik Field Station, Alaska...

For many, 2020 will be remembered as quite a unique year, as many around the world are affected by the coronavirus pandemic and stay home for work, schools are closed, and everyone adapt to the unusual situation. In particular, for scientists, 2020 will be the year of the cancellations of not only international conferences, but also measurement campaigns. Last year, I was trying to organise a measurement campaign in Switzerland in 2020 for my projec t, but for various reasons, this was not possible. As an alternative, we decided to bring reactivity instruments (for both OH and ozone reactivity, the very first time this combination has been ever used to our knowledge) to Pallas in the Finnish Lapland in late March. As Anssi and I were preparing for the trip, COVID-19 slowly took on the news' cycle and Switzerland got hit quite badly by the pandemic. Did we just dodged a bullet? I guess we took a lucky decision without knowing. Still the first cases of COVID-19 were reported als...

After a long journey to get them published, the results of our hydroxyl radical (OH) reactivity measurements in the boreal forest in 2016 are now available in Atmospheric Chemistry and Physics . The final manuscript has been substantially modified from its discussion version, mostly to improve its readability and remove unnecessary parts. The most consequential changes did not severely impact our conclusions, though. Here I give a summary of the findings from our study that includes measurements at the SMEAR II boreal forest station in Hyytiälä, Finland, from April to July 2016, as well as modelling results from our colleagues at the University of Helsinki. We found large total OH reactivity values occurred when the soil was thawing after snow melted (late April). These reactivity peaks were even higher than the high total OH reactivity values in summer (July). Comparing the total OH reactivity measured with the OH reactivity calculated from the known chemical composition at ...

Have you ever had that feeling that a day, a week, or a month has just gone by at such a high pace, that you barely grasped the time flying by? This is what just happened to me as I realized that I haven't been writing for this blog since December! Both life at work and outside of work were quite busy, which contributed to me not noticing time passing by so quickly.  At work, I was busy updating and finalizing a manuscript - previously rejected - which is finally available for discussion in the Atmospheric Chemistry and Physics Discussion (open access) journal. Outside work, theatre has been keeping me busy, as I was helping my friends   from Soup Troupe and The Really Small Theatre Company with their production of Apologia by Alexi Kaye Campbell (as stage manager), which is performed these days in Helsinki. As I was reviewing the past few months to analyse why it went by so fast, I remembered also one thing that I did last year, but about which I dot not write...

Just over a year in the REAC-FORTE project, we have a system running to measure ozone reactivity and we brought it a few weeks ago to the SMEAR II field station for proof-of-concept measurements. We are testing in real conditions the system that we developed based on our experience in Boulder with the group of Prof. Detlev Helmig. While in the lab the temperature and the relative humidity are quite stable, this is not the case in the forest. As the temperatures are decreasing and the relative humidity increase as autumn approaches, it is a good period to get preliminary measurements and to check that our system can run undisturbed when environmental conditions are changing. As none of our other on-line instrument to measure the air composition (gas chromatograph coupled to a mass spectrometer) is available at this time for simultaneous measurements, we collect air samples on adsorption tubes with the help of an auto-sampler (sampling time: 4 hours). These samples are then ana...

Following the installation of our instrumentation at Lompolojänkkä in the Finnish Lapland, the intensive measurement campaign was set for July. I spent two weeks there with my colleague and friend Dr. Simon Schallhart and decided to share with my readers some extracts of my campaign journal. Figure 1. From top to bottom: posing in front of the FMI car; unloading the car from the train in Rovaniemi; the measurement site at Lompolojänkä; wetland chamber; reindeer out of the apartment's window; hiking on Pallastunturit; stormy clouds over Lompolojänkä; oil leak; the FMI car being towed away; birthday champagne at the sauna; evening view over Pallasjärvi lake; branch enclosure for emissions measurements. (Photo credits: Arnaud Praplan and Simon Schallhart, CC-BY-4.0 ) 1 July 2018: The departure. 03:12PM. Today is warm and sunny. I came to FMI around 1PM to meet Simon and load the car. It took less time than expected and everything fitted! Yay! There was time to go to the sh...

The Arctic is predicted to warm up at a quicker pace than other parts of the globe due to climate change. Therefore dramatic changes are expected to happen in that region in the future and scientists express an increasing interest for this region.  As one of our main research interest is focused about substances released into the atmosphere by vegetation (biogenic volatile organic compounds, BVOCs) spring always marks the time when our instruments get to travel again to places after spending the winter in the laboratory for testing and optimization purposes. This year our group is setting up measurements of BVOCs (and other VOCs) and of hydroxyl radical (OH) reactivity in the Arctic. The Finnish Meteorological Institute has been active at Pallas in the Finnish Arctic as early as 1935. Since 1994 Pallas-Sodankylä is established as one of the global observation station of the Global Atmospheric Watch (GAW) programme . The station has one node in Sodankylä at FMI's Arctic Resear...

Prof. Jun Matsumoto ( Waseda University , Tokyo, Japan) is one of the few researcher that has published about his experimental research on ozone reactivity. I recently visited his laboratory on the Tokorozawa Campus to discuss his research. As I was reading about ozone reactivity measurements for proposals, a name stood out: Prof. Jun Matsumoto. He published results from ozone reactivity measurements a few years ago (Matsumoto, 2014) and I contacted him to ask if he would be wiling to host me for a visit at the beginning of the project to familiarize myself with his method. He agreed and as the proposal got funded , I started to organize my trip to Tokyo, which took place at the end of November and beginning of December. Prof. Matsumoto met me on the first day at the Tokorozawa train station, next to my hotel, and we traveled together with train and bus to the university campus. There we first discussed about the current state of his research and on the following day, we visited ...

As part of my postdoctoral work at the Finnish Meteorological Institute, I developed a new implementation of the Comparative Reactivity Method to measure total hydroxyl (OH) reactivity from ambient air and emissions. The description of the instrument and results from our first study in Helsinki to test the instrument's performances have been published in Atmospheric Environment (open access). The total OH reactivity (also called total OH loss rate) is a measure of how much reactive compounds are present in the air. A higher amount of compounds reduces the lifetime of OH. It appears that the total OH reactivity in forested environments is higher than expected from known measured compounds, mostly volatile organic compounds (VOCs) emitted from the vegetation. In order to study this missing OH sink also observed in the summer in the boreal forest (Sinha et al., 2010; Nölscher et al., 2012) during various seasons, Dr. Heidi Hellén proposed to develop an instrument based on the ...