Scavenging Ratios in an Urban Area in the Spanish Basque Country

Figures & data

FIG. 1 Location of the sampling point (Vitoria) in the Spanish Basque Country.

TABLE 1 Diameter particle range collected by the cascade impactor

Basis Airflow Filter type	Once a week and over 24 h 1 m^3 h^−1 Nuclepore, 0.4 μm
Stage	Diameter range (μm)
1	>9.76
2	9.76–4.21
3	4.21–1.73
4	1.73–0.73
5	0.73–0.45
6	<0.45

FIG. 2 Average ionic concentrations of atmospheric particulate fraction collected at Vitoria. Period: January 1995 to December 2000. Units: μg m⁻³.

FIG. 3 Total atmospheric particulate fraction calculated as the addition of the average ionic concentrations in each stage of the CRA-88 impactor. Period: January 1995 to December 2000. Units: μg m⁻³.

TABLE 2 Sea salt ratio values of atmospheric particulate fraction components and the corresponding values for sea water

	Cl^−/Na^+	SO4 ^2−/Na^+	K^+/Na^+	Ca^2+/Na^+
Sea water	1.8	0.25	0.037	0.038
This work	1.64	3.24	0.67	1.66

FIG. 4 Volume-weighted mean concentrations of precipitation collected at Vitoria. Period: January 1995 to December 2000. Units: mg l⁻¹. H⁺ concentration is expressed in μg l⁻¹.

FIG. 5 Average concentration percentage of ionic species found in the ten first fraction of precipitation.

FIG. 6 Scavenging ratios (W) calculated as the relationship between the ionic concentrations in the precipitation and aerosol collected at Vitoria.

TABLE 3 Scavenging ratios in other areas

Reference	Site	Type	Cl^−	NO3−	SO4 ^2−	Na^+	NH4+	K^+	Ca^2+
This work	Vitoria	Urban	3030	2303	2830	3625	1739	1151	3983
Casado et al. 1996	Olaeta	Rural	21936	2319	843	4965	433	1736	4721
Encinas and Casado 1999	Salvatierra	Rural	8729	2788	963	7106	1080	1392	1834
Jaffrezo and Colin 1988	Paris-Francia	Urban	7710		940	744		1325	1759
Dasch and Cadle 1985	Lapeer-USA	Rural	5129	1252	1808	1260		1193	1433
Harrison and Pio 1983	Hazlerigg-UK	Rural	600	370	700	560	350	620	1890
Forti et al. 1990	S. Paulo-Brasil	Urban	3888			468		684	1404
Kane et al. 1994	Mannington-UK	Coastal		204	540	800	1320		420
Guerzoni et al. 1995	Sardinia-Italia	Coastal	2419	754	1728	1708		1630	3459
Pratt and Krupa 1985	Alma-USA	Forestal	886	2927	708		691		706
	Ely-USA	Forestal	949	4913	889		687		2358
	Grand Rapids-USA	Forestal	1392	3833	866		1306		1844
	Sherburne-USA	Rural	902	2118	616		1095		500
	Wright-USA	Rural	1534	2381	597		668		667
	Lamberton-USA	Rural	1464	1799	575		863		540