Reference Graphs - Total Solar Irradiance (TSI)

Note: This post was prepared for a specific discussion I was having at another blog. A blogger there insisted that Total Solar Irradiance hasn’t increased since 1950. My position was, it depended on the source of the TSI data. Since I did not want to fill the thread at that website with a detailed description, I prepared this post and linked to it.

TSI – ACRIM vs PMOD

The two composites of Total Solar Irradiance (TSI), ACRIM and PMOD, are illustrated in Figure 1. Both have been blended with the Lean et al 2000 data that is listed without background.
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Figure 1

The significances of the differences are easier to see if polynomial trend lines are added. Refer to Figure 2.
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Figure 2

In Figure 3, I’ve extended the ACRIM plus Lean et al data back to 1850 for reference.
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Figure 3

I’ve added Figure 4 for those wondering why I’ve included the notation “without background”. There were two data sets provided as part of the Lean et al 2000 study. In Figures 1 through 3, I have been using the data with the least change, the red curve.
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Figure 4