Seasonal variability in 7Be depositional fluxes at Granada, Spain

Beryllium-7 atmospheric deposition and sediment inventories in the Neponset River estuary, Massachusetts, USA

“…In addition, high-tapping thundershowers in the spring and summer months, can enhance stratospheric-tropospheric exchange and the washout of 7 Be via precipitation (Burchfield et al, 1983). As a result, deposition of 7 Be from the atmosphere is often higher during spring and summer months (Azahra et al, 2003;Cooper et al, 2002;Feely et al, 1989;Gonzalez-Gomez et al, 2006;Kulan, 2006;Yamamoto et al, 2006), and this is also indicated by our results (Table 1 and Fig. 2b).…”

Temporal variability of beryllium-7 fallout in southwest UK

“…Wet deposition is the dominant pathway of 7 Be flux to the Earth's surface with dry deposition accounting for <10% (Ioannidou and Papastefanou, 2006;Wallbrink and Murray, 1994). 7 Be deposition (Bq m À2 ) is, therefore, well correlated with rainfall (mm) (Ayub et al, 2009;Caillet et al, 2001;Doering and Akber, 2008b;Gonzalez-Gomez et al, 2006;Mabit et al, 2014) although some variation in depositional flux can be attributed to changes in 7 Be activity in rainwater (Bq L À1 ). This is influenced by atmospheric processes such as washout and circulation of enriched air (Baskaran, 1995;Caillet et al, 2001;Gonzalez-Gomez et al, 2006).…”

“…This concentration gradient can be reduced during folding of the tropopause, which encourages mixing of the troposphere with stratospheric air and this commonly occurs during spring at midlatitudes (Feely et al, 1989). Convective circulation during warmer months can also influence seasonal variation in 7 Be concentrations in surface air by driving the downward transport of 7 Beenriched air from the upper troposphere (Doering and Akber, 2008a;Feely et al, 1989;Ioannidou et al, 2005). Because 7 Bebearing aerosols are readily scavenged by precipitation (Ioannidou and Papastefanou, 2006), seasonal patterns in rainfall can also affect surface air concentrations by removing available 7 Be (washout) (Doering and Akber, 2008a;Feely et al, 1989).…”

“…Convective circulation during warmer months can also influence seasonal variation in 7 Be concentrations in surface air by driving the downward transport of 7 Beenriched air from the upper troposphere (Doering and Akber, 2008a;Feely et al, 1989;Ioannidou et al, 2005). Because 7 Bebearing aerosols are readily scavenged by precipitation (Ioannidou and Papastefanou, 2006), seasonal patterns in rainfall can also affect surface air concentrations by removing available 7 Be (washout) (Doering and Akber, 2008a;Feely et al, 1989). Wet deposition is the dominant pathway of 7 Be flux to the Earth's surface with dry deposition accounting for <10% (Ioannidou and Papastefanou, 2006;Wallbrink and Murray, 1994).…”

“…Higher rates of production in the stratosphere and longer residence time of 7 Be-bearing aerosols creates a concentration gradient relative to the troposphere (Doering and Akber, 2008a). This concentration gradient can be reduced during folding of the tropopause, which encourages mixing of the troposphere with stratospheric air and this commonly occurs during spring at midlatitudes (Feely et al, 1989). Convective circulation during warmer months can also influence seasonal variation in 7 Be concentrations in surface air by driving the downward transport of 7 Beenriched air from the upper troposphere (Doering and Akber, 2008a;Feely et al, 1989;Ioannidou et al, 2005).…”