The climate variability designates the fluctuations of the characteristics climate system. All the spectrum of internal variability is studied in IPSL:

  • Diurnal cycles,
  • Tropical modes (such as the Madden-Julian Oscillation, monsoons, El Niño Southern Oscillation) from the subseasonal to interannual time scales,
  • Decadal to multidecadal modes of variability, such as the Interdecadal Pacific Variability and the Atlantic multidecadal variability,
  • Atmospheric modes of the midlatitudes (North Atlantic Oscillation, planetary Rossby waves, stratospheric circulation…).

The impacts of such modes are actively investigated, especially at the regional time scale where they could be exacerbated. The understanding of the climate variability is also crucial to accurately attribute the observed climate fluctuations, in particular the extreme events (storms, heatwaves, cold spells…).

Observed climate fluctuations result from the interactions between the internal variability and external forcing (from greenhouse gases and aerosols),  hindering detection and attribution of climate change signals. Both the internal and forced component are studied in IPSL.

The climate variability in IPSL is studied with satellite and in situ measurements, regional and climate models, as well as isotopes and climate proxies. The analyses requires more and more advanced statistical tools, for an efficient use of ensembles of climate simulations and observations.

Moderators of the theme

Guillaume Gastineau • LOCEAN-IPSL 

Aurélien Podglajen (since nov. 2021) • LMD-IPSL

Hugo Bellenger (from 2019 to 2021) • LMD-IPSL