At WUWT, Anthony Watts has written about a new paper by John Christy and Richard McNider, which was published in Journal of Applied Meteorology and Climatology of the American Meteorological Society. The researchers were looking at trends in summer-time maximum temperatures centering the analysis on three cities in Alabama, and using stations in Alabama and Tennessee. The purpose was to come up with a methodology to construct "long-term datasets by accounting for heterogeneities or changes in the observed time series without the use of station metadata".There was a press release for the paper, which seems to have been picked up by almost no-one, except WUWT (archived here). In it the authors say:
In addition to creating some arcane mathematical tools useful for creating climate datasets, the team also found daytime high temperature data is less likely to be contaminated by surface issues — such as deforestation, construction, paving and irrigation — than nighttime low temperatures.However I cannot find anything in the paper that supports that specific finding of contamination, or not strongly so.
