Friday, August 17, 2012

"The shifting probability distribution of global daytime and night-time temperatures," by Markus G. Donat & Lisa V. Alexander, GRL 39 (2012); doi: 10.1029/2012GL052459


Geophysical Research Letters, 39 (2012) L14707; doi: 10.1029/2012GL052459
The shifting probability distribution of global daytime and night-time temperatures
Key Points
  • Recent observed warming is investigated using global PDFs
  • PDFs systematically shift and skew towards the hotter part of the distribution
  • In most regions extreme temperatures increased more than mean temperatures
Markus G. Donat (Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia) and Lisa V. Alexander (Climate Change Research Centre, University of New South Wales, and the ARC Centre of Excellence for Climate System Science, University of New South Wales, Sydney, NSW, Australia)

Abstract

Using a global observational dataset of daily gridded maximum and minimum temperatures we investigate changes in the respective probability density functions of both variables using two 30-year periods; 1951–1980 and 1981–2010. The results indicate that the distributions of both daily maximum and minimum temperatures have significantly shifted towards higher values in the latter period compared to the earlier period in almost all regions, whereas changes in variance are spatially heterogeneous and mostly less significant. However, asymmetry appears to have decreased but is altered in such a way that it has become skewed toward the hotter part of the distribution. Changes are greater for daily minimum (night-time) temperatures than for daily maximum (daytime) temperatures. As expected, these changes have had the greatest impact on the extremes of the distribution and we conclude that the distribution of global daily temperatures has indeed become “more extreme” since the middle of the 20th century.
Received 21 May 2012; accepted 19 June 2012; published 31 July 2012.
Donat, M. G. and L. V. Alexander (2012), The shifting probability distribution of global daytime and night-time temperaturesGeophys. Res. Lett.39, L14707, doi: 10.1029/2012GL052459

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