TY - JOUR
T1 - Observations of ozone depletion events in a Finnish boreal forest
AU - Chen, Xuemeng
AU - Quéléver, Lauriane Lucie Josette
AU - Fung, Pak L
AU - Kesti, Jutta
AU - Rissanen, Matti Petteri
AU - Bäck, Jaana Kaarina
AU - Keronen, Petri Ilkka Rinaldo
AU - Junninen, Heikki
AU - Petäjä, Tuukka Taneli
AU - Kerminen, Veli-Matti
AU - Kulmala, Markku Tapio
PY - 2018
Y1 - 2018
N2 - We investigated the concentrations and vertical profiles of ozone over a 20-year period (1996–2016) at the SMEAR II station in southern Finland. Our results showed that the typical daily median ozone concentrations were in the range of 20–50 ppb with clear diurnal and annual patterns. In general, the profile of ozone concentrations illustrated an increase as a function of heights. The main aim of our study was to address the frequency and strength of ozone depletion events at this boreal forest site. We observed more than a thousand of 10 min periods at 4.2 m, with ozone concentrations below 10 ppb, and a few tens of cases with ozone concentrations below 2 ppb. Among these observations, a number of ozone depletion events that lasted for more than 3 h were identified, and they occurred mainly in autumn and winter months. The low ozone concentrations were likely related to the formation of a low mixing layer under the conditions of low temperatures, low wind speeds, high relative humidities and limited intensity of solar radiation.
AB - We investigated the concentrations and vertical profiles of ozone over a 20-year period (1996–2016) at the SMEAR II station in southern Finland. Our results showed that the typical daily median ozone concentrations were in the range of 20–50 ppb with clear diurnal and annual patterns. In general, the profile of ozone concentrations illustrated an increase as a function of heights. The main aim of our study was to address the frequency and strength of ozone depletion events at this boreal forest site. We observed more than a thousand of 10 min periods at 4.2 m, with ozone concentrations below 10 ppb, and a few tens of cases with ozone concentrations below 2 ppb. Among these observations, a number of ozone depletion events that lasted for more than 3 h were identified, and they occurred mainly in autumn and winter months. The low ozone concentrations were likely related to the formation of a low mixing layer under the conditions of low temperatures, low wind speeds, high relative humidities and limited intensity of solar radiation.
KW - 114 Physical sciences
KW - BOREAL FOREST
KW - LONG-TERM OBSERVATIONS
KW - OZONE DEPLETION
U2 - 10.5194/acp-18-49-2018
DO - 10.5194/acp-18-49-2018
M3 - Article
SN - 1680-7316
VL - 18
SP - 49
EP - 63
JO - Atmospheric Chemistry and Physics
JF - Atmospheric Chemistry and Physics
ER -