“The extension of high-latitude arctic land data over the Arctic Ocean is also questionable. Much of the Arctic Ocean is ice-covered even in high summer, so that the surface temperature must remain near freezing. Extending land data out into the ocean will obviously induce substantially exaggerated temperatures.”
They did not do this – tell Pat to read the paper again. They provide an estimate of what that would mean but do not include it in their surface temperature product.
“I am also unconvinced by NOAA’s gap filling in the Arctic, and in my opinion this introduces substantial error into their analysis. I addressed the issue of gap filling in the Arctic in this recent publication: Curry JA, 2014: Climate science: Uncertain temperature trends. Nature Geoscience, 7, 83-84. Relevant text:
Gap filling in the Arctic is complicated by the presence of land, open water and temporally varying sea ice extent, because each surface type has a distinctly different amplitude and phasing of the annual cycle of surface temperature. Notably, the surface temperature of sea ice remains flat during the sea ice melt period roughly between June and September, whereas land surface warming peaks around July 1. Hence using land temperatures to infer ocean or sea ice temperatures can incur significant biases.”
Two things. First it sounds based on your statement like you’re implying you published a peer-reviewed paper on the subject of infilling in the Arctic which is certainly not the case.
Secondly, you have never shown any original analysis to counter the temperature analyses performed by Cowtan and Way and Berkeley with respect to the Arctic. In the time since you made your ‘comments’ there have been a number of papers (see below) which have provided validation for our approach from atmospheric reanalysis datasets, isolated weather stations and satellite datasets. We have provided numerous follow-up investigations which once again support the methodology (see below) and include assessments against the Atmospheric Infrared Sounding Unit for instance. You can’t continue to keep hand-waving on the subject. If you want to say it can’t be done then please show us why – also provide your cross-validation statistics on your proposed improvement ;) If not show us why its better to pretend the Arctic is warming at the global average rate (FYI it’s not).
Comiso, J. C., & Hall, D. K. (2014). Climate trends in the Arctic as observed from space. Wiley Interdisciplinary Reviews: Climate Change, 5(3), 389-409.
Dodd, E. M., Merchant, C. J., Rayner, N. A., & Morice, C. P. (2014). An Investigation into the Impact of using Various Techniques to Estimate Arctic Surface Air Temperature Anomalies. Journal of Climate, (2014).
Simmons, A. J., & Poli, P. (2014). Arctic warming in ERA‐Interim and other analyses. Quarterly Journal of the Royal Meteorological Society.
Updates:
http://www-users.york.ac.uk/~kdc3/papers/coverage2013/updates.html
