To be more specific, I suggest adding the following to the end of the Figure 2 caption: "..... Note that individual series are weighted according to their quality in forming a composite hemispheric-scale time series." The word 'quality' here has been chosen carefully -- as something that is deliberately a bit ambiguous. The point here is to have something that we can fall back on if anyone criticizes *any* specific input series (*not* just Yang).
NOAA’s Arctic report card released at #AGU17
7 hours ago