Periodic Reporting for period 2 - CHAPAs (Chasing pre-industrial aerosols)
Periodo di rendicontazione: 2021-07-01 al 2022-12-31
Aerosol particles affect the climate by interacting with the solar radiation and by acting as cloud condensation nuclei; however, their net effect remains of highest uncertainty, specifically when quantifying their relationship to anthropogenic greenhouse gases. It has been estimated that 45% of the variance of aerosol forcing arises from uncertainties in natural emissions. This highlight the importance of understanding pristine preindustrial-like environments, with natural aerosols only. One of the great challenges in understanding preindustrial aerosols and their sources resides in identifying the processes by which new particles form and grow from oxidized vapours.
What is the problem/issue being addressed?
Understanding how particles were formed in the pre-industrial time is fundamental in order to fully understand the climate change. This is important because, although natural emissions do not produce the forcing, they affect the baseline that the forcing is calculated against. Basically we are missing information on how was the climate and the atmospheric composition before the industrial revolution and this limit our understanding about the present climate change and global warming situation.
Why is it important for society?
Climate change is on the biggest challenge that our society is facing right now. A better understanding of this phenomena is fundamental for a proper risk assessment and predict future scenario. Only by properly know the past atmosphere we can try to understand the present and properly predict the future.
What are the overall objectives?
The main objective behind this project is to understand of how new particles were formed in the pre-industrial era. Model studies have predicted that pure biogenic nucleation was probably one of the most important NPF mechanisms in the past. However, these predictions rely only on few laboratory experiments. In order to fully characterized this process I have 4 objectives:
1. To identify the mechanism driving new particle formation in remote and pristine areas, where anthropogenic activity is low or absent.
2. To identify the mechanism driving new particle formation at high altitudes over the sea, especially above oceans.
3. Confirm the observed mechanism with carefully planned laboratory experiments.
4. To understand and quantify the importance of this process in the pre-industrial era.
What is the problem/issue being addressed?
Understanding how particles were formed in the pre-industrial time is fundamental in order to fully understand the climate change. This is important because, although natural emissions do not produce the forcing, they affect the baseline that the forcing is calculated against. Basically we are missing information on how was the climate and the atmospheric composition before the industrial revolution and this limit our understanding about the present climate change and global warming situation.
Why is it important for society?
Climate change is on the biggest challenge that our society is facing right now. A better understanding of this phenomena is fundamental for a proper risk assessment and predict future scenario. Only by properly know the past atmosphere we can try to understand the present and properly predict the future.
What are the overall objectives?
The main objective behind this project is to understand of how new particles were formed in the pre-industrial era. Model studies have predicted that pure biogenic nucleation was probably one of the most important NPF mechanisms in the past. However, these predictions rely only on few laboratory experiments. In order to fully characterized this process I have 4 objectives:
1. To identify the mechanism driving new particle formation in remote and pristine areas, where anthropogenic activity is low or absent.
2. To identify the mechanism driving new particle formation at high altitudes over the sea, especially above oceans.
3. Confirm the observed mechanism with carefully planned laboratory experiments.
4. To understand and quantify the importance of this process in the pre-industrial era.
The ERC project has started in January 2020, exactly the same time of the COVID outbreak, because of that the planning of the project has been heavily affected. The core of the project is to perform comprehensive and advanced observation in remote and pristine location around the world. Those type of measurements usually sophisticated logistic preparation and obviously been able to freely travel around the world. Because of COVID this was not really possible until now and therefore we had to adjust our plan to what it was possible. Despite all of that we were still able to perform several measurements and when not possible analyses older data set that would potentially fit the project.
During the COVID outbreak we have used the situation to better understanding how aerosol sources changed. We have performed a measurement campaign in North Italy, an area that has been heavily affected by the COVID outbreack followed by lockdown policies. In this study we have realized what is the role traffic in such polluted area.
In addition to those measurements we have performed measurements at the Izana station, Tenerife, Canary Island at 2400 m. Here the data analysis has just started and the results will be published in the next years.
Other locations where we have been measuring during this time were Tomsk, in Siberia, Russia and at Ny-Ålesund, in Svalbard.
Where it was not possible to organize new field observations we have analyzed data that were previously collected. This has led to several very good scientific results that will try to summarize here.
- We have found the that Himalayan region can act as an aerosol factory. This is due to the tree emissions at the Himalayan foothills. Those emissions are trasported at high altitude and after forming new particle are then emitted into the free troposphere.
- We have found observational evidence for the formation of aerosol particles from pure biogenic HOM vapours in the absence of sulfuric acid contributing to the nighttime clustering events in a peatland in Siikaneva, southern Finland. Shading new light into the nucleation mechanism representative of the pre-industrial era.
As promised in this proposal, both of these results provide implications into a better understanding of pre-industrial aerosol formation, which will set the baseline for estimations of the impact of present and future aerosol on climate.
During the COVID outbreak we have used the situation to better understanding how aerosol sources changed. We have performed a measurement campaign in North Italy, an area that has been heavily affected by the COVID outbreack followed by lockdown policies. In this study we have realized what is the role traffic in such polluted area.
In addition to those measurements we have performed measurements at the Izana station, Tenerife, Canary Island at 2400 m. Here the data analysis has just started and the results will be published in the next years.
Other locations where we have been measuring during this time were Tomsk, in Siberia, Russia and at Ny-Ålesund, in Svalbard.
Where it was not possible to organize new field observations we have analyzed data that were previously collected. This has led to several very good scientific results that will try to summarize here.
- We have found the that Himalayan region can act as an aerosol factory. This is due to the tree emissions at the Himalayan foothills. Those emissions are trasported at high altitude and after forming new particle are then emitted into the free troposphere.
- We have found observational evidence for the formation of aerosol particles from pure biogenic HOM vapours in the absence of sulfuric acid contributing to the nighttime clustering events in a peatland in Siikaneva, southern Finland. Shading new light into the nucleation mechanism representative of the pre-industrial era.
As promised in this proposal, both of these results provide implications into a better understanding of pre-industrial aerosol formation, which will set the baseline for estimations of the impact of present and future aerosol on climate.
We believe that the major progress done so far have been this very valuable publications about new particle formation on top of the Himalayas and Andes. These findings have pave a road that we are following now and might end up in a ground breaking discovery.
As mentioned above, we now know that the whole Himalaya can act as an aerosol factory. This means that the trees at the Himalayan foothills are responsible for emitting particle precursors that once they have reached a certain altitude they form new particles and then transported into the free troposphere. This is now been established, however, what we don't know, it's the impact of those particle on the upper troposphere and climate. Therefore, by the end of the project we would like to quantify this effect. This is particularly important because we believe that this process didn't change since the pre-industrial time and understanding this process could help us in understanding present and future climate. Additionally, using model simuation we would like to test an idea that can be extremely innovative. If the Himalayan aerosol factory can really produce so many particles that can affect the climate it might be that by planting more trees we could really help in increasing the forestation and at the same time cooling the planet. That would be a sort of Natural Geoengineering. The hypothesis behind is that more trees will emit more biogenic gases that would act as particle precursors. Once the particles are formed can be transported to the free troposphere and then act as cloud condensation nuclei and might be able to cool the planet. We believe that any insight here would already be an extremely useful result.
As mentioned above, we now know that the whole Himalaya can act as an aerosol factory. This means that the trees at the Himalayan foothills are responsible for emitting particle precursors that once they have reached a certain altitude they form new particles and then transported into the free troposphere. This is now been established, however, what we don't know, it's the impact of those particle on the upper troposphere and climate. Therefore, by the end of the project we would like to quantify this effect. This is particularly important because we believe that this process didn't change since the pre-industrial time and understanding this process could help us in understanding present and future climate. Additionally, using model simuation we would like to test an idea that can be extremely innovative. If the Himalayan aerosol factory can really produce so many particles that can affect the climate it might be that by planting more trees we could really help in increasing the forestation and at the same time cooling the planet. That would be a sort of Natural Geoengineering. The hypothesis behind is that more trees will emit more biogenic gases that would act as particle precursors. Once the particles are formed can be transported to the free troposphere and then act as cloud condensation nuclei and might be able to cool the planet. We believe that any insight here would already be an extremely useful result.