I can't answer regarding GISS USCHCN, because I don't know anything about it.
That said, most of the legit complaints I've seen are regarding the extrapolation and interpolation of data. Not actually wrong data. It looks like the graph you have shows an "adjustment". That's not the level of damage to raw data I'm talking about. I'm talking about removing data points or simply recording different numbers within the raw data itself. As in, if the thermometer says 72, and you write down that it said 82. Or you warmed the thermometer.
That is exactly what happened. The raw data no longer officially exists. When you go looking for the raw data they give you the adjusted data claiming it is the raw data. This switch happened nearly a decade ago.
So why don't you apply this line of thinking to climate change, since that is exactly what is happening with the GISS USGHCN?
I can't answer regarding GISS USCHCN, because I don't know anything about it.
That said, most of the legit complaints I've seen are regarding the extrapolation and interpolation of data. Not actually wrong data. It looks like the graph you have shows an "adjustment". That's not the level of damage to raw data I'm talking about. I'm talking about removing data points or simply recording different numbers within the raw data itself. As in, if the thermometer says 72, and you write down that it said 82. Or you warmed the thermometer.
That is exactly what happened. The raw data no longer officially exists. When you go looking for the raw data they give you the adjusted data claiming it is the raw data. This switch happened nearly a decade ago.
I don't think that's true, but at least we are on the same page.