Atmospheric Deposition of 7Be in the Southeast of China: A Case Study in Xiamen

Abstract

Be deposition and precipitation, existing in both northeast and southwest monsoon seasons, suggested the dominant removal of atmospheric 7 Be via precipitation. However, the correlations showed a large slope for the northeast monsoon season, indicating higher 7 Be contents in the atmosphere during the northeast monsoon prevailing months, supported by the precipitation-normalized 7 Be and the temporal variability of 7 Be/ 210 Pb ratios. Such a scenario revealed more intensive exchange of air mass between the stratosphere and troposphere during the northeast monsoon prevailing months. Together with the high pollutant concentrations in ambient air observed in these seasons, the results indicated that the pollutants in Xiamen might enter into the upper troposphere via vertical air mass exchange.

Scavenging and fractionation of particle-reactive radioisotopes 7Be, 210Pb and 210Po in the atmosphere

“…3 and Table 2) show that the measured fluxes are mainly contributed by the wet precipitation. For 7 Be, our measured fluxes are consistent with those of $0.03-45.1 Bq m À2 d À1 observed by Zhang et al (2016) in 2012 to 2013 at the same site. An important feature in the measurements of the 7 Be, 210 Pb and 210 Po activities in rain waters is their large temporal variability.…”

Analysis of the influence of solar activity and atmospheric factors on 7Be air concentration by seasonal-trend decomposition

“…The correlation observed with the precipitations is supported by recent studies, which found a strong correlation between precipitations and 7 Be deposition fluxes (Chen et al, 2016;Zhang et al, 2016). In constrast, many studies have found a non-significant correlation between 7 Be row data and the total monthly precipitation per month (Azahra et al, 2004b;Ali et al, 2011;Pham et al, 2011;Kotsopoulou and Ioannidou, 2012).…”

Source and Fate of Dissolved Black Carbon in the Western South China Sea During the Southwest Monsoon Prevailing Season

“…Asia contributes more than one third of the global aerosol BC emission (Bond et al, ; Jurado et al, ). Since the atmospheric deposition over the SCS is heavily influenced by the Asian monsoons (Wang et al, ; Zhang et al, ), the SCS is expected to be an important region receiving atmospherically deposited BC (Liu et al, ). Meanwhile, about 1.7 × 10 12 m 3 of river water is discharged into the SCS each year, probably inputting large amounts of DBC to the SCS as observed in the sediments (Jia et al, ; Sun et al, ).…”