S&W combined two different types of data, and it is well - known that such combinations in themselves may introduces spurious trends. (realclimate.org)
The reality seems to be that some poorly worded descriptions of quite normal data - processing activities were made public: with many data sets, it is necessary to subtract spurious trends to see what is actually the main process at work. (environmentalresearchweb.org)
It was because of this that we tend to believe that, if there are spurious trends in the output of the NCEP model, then they most likely derive from the radiosonde input data rather than from the behaviour of the model. (climateaudit.org)