TY - JOUR
T1 - A modelling study of OH, NO3 and H2SO4 in 2007- 2018 at SMEAR II, Finland
T2 - Analysis of long-term trends
AU - Chen, Dean
AU - Xavier, Carlton
AU - Clusius, Petri
AU - Nieminen, Tuomo
AU - Roldin, Pontus
AU - Qi, Ximeng
AU - Pichelstorfer, Lukas
AU - Kulmala, Markku
AU - Rantala, Pekka
AU - Aalto, Juho
AU - Sarnela, Nina
AU - Kolari, Pasi
AU - Keronen, Petri
AU - Rissanen, Matti P.
AU - Taipale, Ditte
AU - Foreback, Benjamin
AU - Baykara, Metin
AU - Zhou, Putian
AU - Boy, Michael
N1 - Publisher Copyright:
© 2021 The Author(s).
PY - 2021
Y1 - 2021
N2 - Major atmospheric oxidants (OH,O3 and NO3) dominate the atmospheric oxidation capacity, while H2SO4 is considered as a main driver for new particle formation. Although numerous studies have investigated the long-term trend of ozone in Europe, the trends of OH, NO3 and H2SO4 at specific sites are to a large extent unknown. The one-dimensional model SOSAA has been applied in several studies at the SMEAR II station and has been validated by measurements in several projects. Here, we applied the SOSAA model for the years 2007-2018 to simulate the atmospheric chemical components, especially the atmospheric oxidants OH and NO3, as well as H2SO4 at SMEAR II. The simulations were evaluated with observations from several shorter and longer campaigns at SMEAR II. Our results show that daily OH increased by 2.39% per year and NO3 decreased by 3.41% per year, with different trends of these oxidants during day and night. On the contrary, daytime sulfuric acid concentrations decreased by 2.78% per year, which correlated with the observed decreasing concentration of newly formed particles in the size range of 3- 25 nm with 1.4% per year at SMEAR II during the years 1997-2012. Additionally, we compared our simulated OH, NO3 and H2SO4 concentrations with proxies, which are commonly applied in case a limited number of parameters are measured and no detailed model simulations are available.
AB - Major atmospheric oxidants (OH,O3 and NO3) dominate the atmospheric oxidation capacity, while H2SO4 is considered as a main driver for new particle formation. Although numerous studies have investigated the long-term trend of ozone in Europe, the trends of OH, NO3 and H2SO4 at specific sites are to a large extent unknown. The one-dimensional model SOSAA has been applied in several studies at the SMEAR II station and has been validated by measurements in several projects. Here, we applied the SOSAA model for the years 2007-2018 to simulate the atmospheric chemical components, especially the atmospheric oxidants OH and NO3, as well as H2SO4 at SMEAR II. The simulations were evaluated with observations from several shorter and longer campaigns at SMEAR II. Our results show that daily OH increased by 2.39% per year and NO3 decreased by 3.41% per year, with different trends of these oxidants during day and night. On the contrary, daytime sulfuric acid concentrations decreased by 2.78% per year, which correlated with the observed decreasing concentration of newly formed particles in the size range of 3- 25 nm with 1.4% per year at SMEAR II during the years 1997-2012. Additionally, we compared our simulated OH, NO3 and H2SO4 concentrations with proxies, which are commonly applied in case a limited number of parameters are measured and no detailed model simulations are available.
UR - http://www.scopus.com/inward/record.url?scp=85131757406&partnerID=8YFLogxK
U2 - 10.1039/d1ea00020a
DO - 10.1039/d1ea00020a
M3 - Article
AN - SCOPUS:85131757406
SN - 2634-3606
VL - 1
SP - 449
EP - 472
JO - Environmental Science: Atmospheres
JF - Environmental Science: Atmospheres
IS - 6
ER -