Seasonality of ⁷Be concentrations in Europe and influence of tropopause height

Figures & data

Fig. 1 Map of ⁷Be sampling sites. The stations given in squares are selected for latitudinal analysis (Section 3.2).

Table 1. Station name, coordinates (latitude, longitude, altitude above sea level), number of operability sampling periods and temporal resolution.

Stations	LAT (°N)	LON (°E)	Altitude (m a.s.l)	Operability (samplings during 2001–2010)	Temporal resolution
Ivalo	68.64	27.57	130	418	Weekly (between 6 and 8 d)
Umea	63.85	20.34	45	478
Kista	59.4	17.93	16	488
Harku	59.39	24.58	36	400
Risoe	55.69	12.10	9	448
Bilthoven	52.11	5.18	4	501
Offenbach	50.1	8.77	107	445
Praha	50.09	14.42	202	446
Luxembourg	49.63	6.13	280	434
Vienna	48.22	16.35	193	506
Freiburg	48.20	7.87	411	466
Milano	45.47	9.18	125	349
Bilbao	43.17	−2.94	380	468
Barcelona	41.38	2.12	52	472
Madrid	40.45	−3.69	715	471
Sevilla	37.39	−6.01	8	475
Laguna	28.46	−16.29	358	200

Fig. 2 Variograms for ⁷Be and TPH: all available data (a and b), and separately winter (c and d) and summer (e and f) seasons.

Fig. 3 Interannual variability of ⁷Be activity concentrations.

Fig. 4 Mean monthly variability of ⁷Be activity concentrations (2001–2010).

Fig. 5 Correlation coefficient between mean monthly ⁷Be and TPH (2001–2010). White and black columns denote significant and non-significant correlations, respectively.

Fig. 6 Latitudinal variation of the monthly evolution of ⁷Be and TPH (2001–2010).

Fig. 7 (a) Correlogram (a time lag from 0 to 7 d) between ⁷Be surface concentration and tropopause height, and maps showing the day on which the maximum correlation coefficient between TPH and ⁷Be is observed at the selected stations during (b) winter and (c) summer. ‘Nsgn’ stands for a correlation coefficient not statistically significant.

Fig. 8 Winter (a) and summer (b) significant correlation coefficients between ⁷Be and TPH with a varying time lag from zero to seven for the selected stations.