1360
1365
1370
800
1000
1200
1400
1600
1800
2000
0
20
40
60
80
100
120
140
160
180
200
1610
1660
1710
1760
1810
1860
1910
1960
2010
1357
1358
1359
1360
1361
1362
1363
10/2/2003
24/6/2004
6/11/2005
21/3/2007
2/8/2008
15/12/2009
A
B
C
Irradiance solaire (W/m 2 )
Age (AD)
Age (AD)
Irradiance solaire (W/m 2 )
Nombre de tâches solaires
Minimum
de
Maunder
Date
Solar irradiance (W/m
2
)
Solar irradiance (W/m
2
)
Number of solar spots
Maunder
minimum
Time
Time
Fig. 1.3 a Variations in solar energy reconstructed from changes in
the beryllium content of polar ice and from the modeling of stellar
activity. It should be noted that the mean values calculated using
stellar-activity modeling are higher, by about 5 W/m
2
, compared with
values measured using satellites. b Variations in energy emitted by the
Sun, NASA satellite measurements. c Changes in the number of
sunspots observed by astronomers since 1610
1 The Climate System: Its Functioning and History
5