Seasonal variations of dissolved organic carbon in precipitation over urban and forest sites in central Poland

Abstract

Spatial and temporal variability of carbon species in rainwater (bulk deposition) was studied for the first time at two sites located in urban area of Poznań City and protected woodland area (Jeziory), in central Poland, between April and December 2013. The mean concentration of total carbon (TC) for the first site was 5.86 mg L−1, whereas for the second, 5.21 mg L−1. Dissolved organic carbon (DOC) concentration accounted for, on average, 87 and 91 % of total carbon in precipitation at urban and non-urban sites, respectively. Significant changes in TC concentrations in rainwater were observed at both sites, indicating that atmospheric transformation, transport, and removal mechanisms of carbonaceous particles were affected by seasonal fluctuations in biogenic/anthropogenic emission and meteorological conditions (i.e., precipitation height and type, atmospheric transport). During the warm season, the DOC concentration in rainwater was mostly influenced by mixed natural and anthropogenic sources. In contrast, during the cold season, the DOC concentration significantly increased mainly as a result of anthropogenic activities, i.e., intensive coal combustion, domestic wood burning, high-temperature processes, etc. In addition, during the winter measurements, significant differences in mean DOC concentration (Kruskal-Wallis test, p < 0.05) were determined for rain, mixed rain-snow, and snow samples. It was found that rainwater TOC concentration measured in Poznań and Jeziory reflected a combination of local, regional, and distant sources. Backward trajectory analysis showed that air masses advected from polluted regions in western Europe largely affect the DOC amount in rainwater, both at urban and non-urban sites. These data imply that carbonaceous compounds are of crucial importance in atmospheric chemistry and should be considered as an important parameter while considering wet deposition, reactions with different substances, especially over polluted environments.

Characteristics of wet carbon deposition in a semi-arid catchment at Loess Plateau, China

“…) (Yan and Kim, 2012), and Poland (4.72-5.10 mg C L -1 ) (Siudek et al, 2015). Such differences between the 230 present studied region and other regions might be partly explained by the various carbon sources, meteorological type, sampling time scale and methods in mainland or coastal regions.…”

“…Thus, the lack of measurement and quantitative knowledge, such as corresponding sources, chemical composition and variation pattern, has been shown the need for substantial information. Around the world, only few 40 quantitative studies can be found on carbon wet deposition, such as in Lithuania (Armalis, 1999), Poland (Siudek et al, 2015), USA (Iavorivska et al, 2017), New Zealand (Kieber et al, 2002) and Brazil (Coelho et al, 2008), which DOC flux in rainfall ranged 1.2 to 5.4 g C m -2 yr -1 . Not until recently, the only measurement data available were those related to wet deposition in northern and Tibetan region of China (Li et al, 2016;Pan et al, 2010).…”

“…Furthermore, it has been demonstrated that emissions of incomplete fossil fuel combustion were a key source of DOC in precipitation, such as in 55 northern and Tibetan of China (Li et al, 2016;Pan et al, 2010) , USA (Mladenov et al, 2012;Raymond, 2005), Europe (Siudek et al, 2015) and New Zealand (Willey et al, 2000). For instance, contribution of fossil fuel combustion in DOC was around 22-28% in North America, European, and Tibetan of China.…”

Characteristics of wet dissolved carbon deposition in a semi-arid catchment at the Loess Plateau, China

“…The input meteorological data were from the Global Data Assimilation System (GDAS). The trajectories were generated for 168 h hindcast starting at 100/500/1000 m above ground level and vertical motion based on model vertical velocity (Siudek et al, 2015). The weekly air parcel backward trajectories with a 6 h interval were calculated for the Yangjuangou catchment (36 • 41 50.9 N, 109 • 31 37.6 E) during July to September 2015.…”

“…Dissolved carbon deposition concentration and flux in rainfall are not general parameters in monitoring networks, such as the National Atmospheric Deposition Program (USA), European Monitoring Evaluation Programme (European Union) and Chinese Ecosystem Research Network (China) (Iavorivska et al, 2016a). In general, only few studies have assessed the dissolved carbon deposition via rainfall, such as the USA (1.1-2.9 mg C L −1 ; McDowell and Likens, 1998;Quideau and Bockheim, 1997;Willey et al, 2000), .1 mg C L −1 ; Coelho et al, 2008), New Zealand (0.1-4.8 mg C L −1 ; Kieber et al, 2002), Korea (0.2-9.4 mg C L −1 ; Yan and Kim, 2012), and Poland (4.7-5.1 mg C L −1 ; Siudek et al, 2015). Until recently, the only measurement data available were those related to wet dissolved carbon deposition in the northern and Tibetan region of China (Li et al, 2016;Pan et al, 2010).…”