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...

In our latest publication, we investigated with total hydroxyl radical (OH) reactivity measurements our understanding of emissions from three tree species found in the boreal forest. The unexplained fraction of the reactivity remain high in some circumstances. We recently published in Biogeosciences the results of our study from 2017, where we analysed the emissions from three different trees with gas chromatographic methods and total OH reactivity instrumentation. We analysed emissions at the branch level with enclosure for birch, spruce, and pine. Our findings are that emissions do vary in amount and composition throughout the growing season and we could show, based on reactivity measurements, that the emissions are not fully characterized chemically. In particular when trees were subject to stress (that was clearly visible with, for instance, browning leaves or needles) the reactivity of the emissions increased a lot and we observed simultaneously an increase of emissions of Green L...

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 ...

This year was my first time at the General Assembly of the European Geosciences Union (EGU). Even though it felt overwhelming at times, it is also a very stimulating conference including sessions related to important topics beyond scientific topics, such as short courses about various subjects (e.g. peer-review, grants) and more general sessions about scientists' well-being and diversity and equality for instance. The EGU General Assembly (GA) is a week-long conference taking place yearly in Vienna since 2005 (the first GA was in Nice, France, in 2004). It is huge (really!) and brings together over 16'000 scientists (new record this year) from 113 countries representing all fields related to space and Earth Science, such as atmospheric sciences, climate science, oceanography, biogeosciences, cryosphere research, hydrology, seismology, volcanology, planetary science, among many others. As the Atmospheric Sciences division is on of the largest of EGU and as I have be...

It is a yearly routine: the temperature slowly increase and there is more light. It is then time to transport our instrumentation to the field! After our measurement campaign in Lapland last year (I wrote about it previously here and here ), this year we are back at the SMEAR II station in Hyytiälä in southern Finland. The SMEAR II station has become a hotspot for atmospheric sciences starting from the mid-1990s. The Finnish Meteorological Institute performs routine measurements there and research is also conducted at the site on Biogenic Volatile Organic Compounds (BVOCs) and other topics related to air quality. We performed an OH reactivity study at this site in 2016 (which is currently under review for Atmospheric Chemistry and Physics, see the open discussion ), which was building on previous studies by Sinha et al. (2010) and Nölscher et al. (2012) . Then, we extended the study period to include the spring and not only summer as the mentioned earlier studies. One result of ...

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...

From 10 to 15 June I visited with a few of my colleagues the Gordon Research Conference 2018 on Biogenic Hydrocarbons and the Atmosphere . The conference was held in Les Diablerets, close to my native city in the Swiss Alps. Gordon Research Conferences are known to be at the cutting-edge of research with their policy of presenting latest results and strict rules about not disclosing anything that has been discussed at the conference to non-participants. It encourages discussing cutting edge research in an informal setting with lots of horizontal learning. Young and established researchers mix very well during meals, poster sessions, and free time activities. This was my second Gordon Research Conference after the one on Atmospheric Chemistry last year in Maine, U.S.A. It was a great opportunity to catch up with colleagues from various institutions, in particular with other researchers using the Comparative Reactivity Method (CRM) for total OH reactivity measurements. We could disc...

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...