Articles | Volume 7, issue 1
Earth Syst. Dynam., 7, 231–249, 2016
Earth Syst. Dynam., 7, 231–249, 2016

Research article 11 Mar 2016

Research article | 11 Mar 2016

Imprints of climate forcings in global gridded temperature data

Jiří Mikšovský1,2, Eva Holtanová1, and Petr Pišoft1 Jiří Mikšovský et al.
  • 1Department of Atmospheric Physics, Faculty of Mathematics and Physics, Charles University in Prague, Czech Republic
  • 2Global Change Research Institute, Academy of Sciences of the Czech Republic, Brno, Czech Republic

Abstract. Monthly near-surface temperature anomalies from several gridded data sets (GISTEMP, Berkeley Earth, MLOST, HadCRUT4, 20th Century Reanalysis) were investigated and compared with regard to the presence of components attributable to external climate forcings (associated with anthropogenic greenhouse gases, as well as solar and volcanic activity) and to major internal climate variability modes (El Niño/Southern Oscillation, North Atlantic Oscillation, Atlantic Multidecadal Oscillation, Pacific Decadal Oscillation and variability characterized by the Trans-Polar Index). Multiple linear regression was used to separate components related to individual explanatory variables in local monthly temperatures as well as in their global means, over the 1901–2010 period. Strong correlations of temperature and anthropogenic forcing were confirmed for most of the globe, whereas only weaker and mostly statistically insignificant connections to solar activity were indicated. Imprints of volcanic forcing were found to be largely insignificant in the local temperatures, in contrast to the clear volcanic signature in their global averages. Attention was also paid to the manifestations of short-term time shifts in the responses to the forcings, and to differences in the spatial fingerprints detected from individual temperature data sets. It is shown that although the resemblance of the response patterns is usually strong, some regional contrasts appear. Noteworthy differences from the other data sets were found especially for the 20th Century Reanalysis, particularly for the components attributable to anthropogenic forcing over land, but also in the response to volcanism and in some of the teleconnection patterns related to the internal climate variability modes.

Short summary
Using regression analysis, near-surface temperatures from several gridded data sets were investigated for the presence of components attributable to external climate forcings and to major internal climate variability modes, over the 1901–2010 period. The spatial patterns of local temperature response and their combination in globally averaged temperature were shown and discussed, with special focus on highlighting the inter-dataset contrasts.
Final-revised paper