Climatic Data - Climate Change: Identification and Projections - page 24

Finally, reconstructions covering several millennia are available, which
are based on isotopic proxies (Figure 2.11). Unfortunately, they are not
linked to satellite measurements, which means they we are not able to use
them. Moreover, their scales are incompatible: visibly, they have been
calibrated with different four-century TSIs.

1368

1367

1366

1365

1364

1363

Steinhilber, 2009
Bard, 2000
Delayg u e, 2010

1362

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Figure 2.11. Irradiance reconstructions over millennia

The Bard line could conveniently align with lean1, the others with timv13
or timv15 , but it would be inappropriate to recalibrate this data behind the
authors' backs. However, cosmogenic proxies, like those in Figure 2.8
should, by their very nature, be calibrated with TSI observations or
the partial reconstructions in Figure 2.9. We are therefore completely free to
do so.

A selection
The correlation of all the solar activity indicators (TSI, spots, magnetic
field, cosmogenic proxies) justifies them being merged into a single
representation. The TSI is adopted as a common reference, although the
energetic factor alone does not appear to be sufficient to take into account all
the climatic variations caused by solar activity. In practice, we link the two