Seasonal changes in stable nitrogen isotopic composition in fine aerosols at a rural background station Košetice (Central Europe).

0573518 - ÚCHP 2024 eng A - Abstract
Vodička, Petr - Kawamura, K. - Schwarz, Jaroslav - Kunwar, B. - Ždímal, Vladimír
Seasonal changes in stable nitrogen isotopic composition in fine aerosols at a rural background station Košetice (Central Europe).
[EGU General Assembly 2020 online. Munich, 04.05.2020-08.05.2020]
Method of presentation: Prezentace
R&D Projects: GA MŠMT(CZ) LM2018122; GA MŠMT(CZ) EF16_013/0001315
Grant - others:JSPS 24221001; JSPS(JP) P16760
Institutional support: RVO:67985858
Keywords : nitrogen isotopic composition * aerosols * rural background station Košetice
OECD category: Meteorology and atmospheric sciences
https://meetingorganizer.copernicus.org/EGU2020/EGU2020-3469.html

The stable nitrogen isotope ratios (δ15N) of total nitrogen (TN) were studied for fine aerosol particles (PM1) collected with a 24-h time resolution every two days at a Central European rural background site from September 27, 2013, to August 9, 2014 (n=146).
We observed a seasonal cycle of enrichment and depletion of 15N in aerosol particles with lower values in winter and higher values in summer. The majority of the yearly data showed a strong correlation between δ15N and ambient temperature, supporting an enrichment of 15N via isotopic equilibrium exchange between the gas and particulate phases. This process seemed to be one of the main mechanisms for 15N enrichment at the Košetice site, especially during spring. The most 15N-enriched summer and most 15N-depleted winter samples were limited by the partitioning of nitrate in aerosols and suppressed equilibrium exchange between gaseous NH3 and aerosol NH4+. During winter, we observed an event with the lowest δ15N values which deviate from temperature dependence. The winter event was connected with prevailing southeast winds and the lowest δ15N values were probably associated with agriculture emissions of NH3 under low-temperature conditions (<0°C).
Permanent Link: https://hdl.handle.net/11104/0343951