The latest conspiracy theory from science deniers at WUWT is that the National Snow and Ice Data Center (NSIDC) is up to something nefarious. (Seeing nefarious intent in the most innocuous actions is one of the hallmarks of conspiratorial thinking.)All the fuss was about a new version of NSIDC's Sea Ice Index. It's gone from version 2 to version 3. In the latest version, monthly averages are calculated in a different way. The new version only affects monthly averages, not anything else. From the analysis report:
The Sea Ice Index has been updated to Version 3 (V3). The key update in V3 is a change in the method for calculating the numerical monthly averages of sea ice extent and sea ice area data values; that is, the data distributed in .csv and .xlsx format. This change impacts only the monthly data values in the Sea Ice Index time series and not monthly sea ice extent and concentration maps that accompany the data product, that is, the .png, .tif, and shapefile archives. Daily data are also not impacted, nor are any current conclusions drawn from the Sea Ice Index data set about the state of sea ice in either the Arctic or the Antarctic. This change is being made in response to questions raised by users of the product concerning how the monthly average ice extent and areas are calculated.
