Jul 19, 2017

Observed trends in the magnitude and persistence of monthly temperature variability

Timothy M. Lenton, Vasilis Dakos, Sebastian Bathiany, Marten Scheffer
Scientific Reports
  • States that the issues of whether climate variability is changing, and if so, whether this is due to anthropogenic forcing, are subjects of ongoing debate
  • Scans monthly surface temperature indices and spatial datasets to look for trends in variance and autocorrelation (persistence)
  • Shows that monthly temperature variability and autocorrelation increased over 1957–2002 across large parts of the North Pacific, North Atlantic, North America and the Mediterranean
  • Shows that (multi)decadal internal climate variability appears to influence trends in monthly temperature variability and autocorrelation
  • Finds that historically-forced climate models do not reproduce the observed trends in temperature variance and autocorrelation, consistent with the models poorly capturing (multi)decadal internal climate variability
  • Hypothesizes that slowing down of sea surface temperature variability contributed to increases in land temperature variability and autocorrelation, which in turn contributed to persistent droughts in North America and the Mediterranean