Stratosphere and Climate

Stratospheric sudden warmings are extreme dynamical events of the polar upper atmosphere with remote potential influence on surface weather and climate at middle-high latitudes. Typically these events occur during the boreal winter season – but their statistics for the austral seasons are still uncertain. In the equatorial stratosphere, positive and negative zonal winds fully encircling the globe are alternating each other, with an approximate periodicity of 28 months, e.g. the so-called Quasi-Biennial Oscillation (QBO). The 2-way dynamical connection between the QBO and tropospheric weather has potential to provide new information on key questions on surface climate at tropical latitudes.

The initiative aims at discerning the upper atmosphere influences on surface climate by focusing on the mediating role of stratospheric dynamics in connecting changes in the Earth system. The initiative cuts across the AES-department by taking into consideration the interacting character of the troposphere-stratosphere system when framing scientific questions. Specific topics are:

  • The 11-year solar cycle variations and surface climate.
  • Remote influences of volcanic eruptions and geo-engineering.
  • Ozone depletion/recovery and their remote effects on the Earth system, including air-ocean carbon fluxes.
  • Factors controlling and remote influences of stratospheric water vapor.
  • Potential predictability of the surface climate at seasonal and decadal scales.
  • Induced stratospheric changes by anthropogenic climate change and its feedback on surface climate

Some of these topics are currently addressed within the AES-department working groups as described in their pages and explored in the EU funded projects COMBINE and IMPLICC. Some topics are reaching out to the ocean and land departments. At the international level, the initiative contributes to a number of activities of the World Climate Research Program (WCRP)’s Stratospheric Process and their Role in Climate (SPARC) project, such as CCMVal, DynVar, Gravity Waves and SOLARIS.

 

MPI, November 2011. Posters on Stratosphere - Troposphere coupling:  

  • Multi-decadal variability in a hierarchy of MPI-ESM model set-ups. Jungclaus and Zanchettin; PB-Z-203
  • Influence of small scale processes on the dynamics of the quasi-biennial oscillation. Krismer et al; PB-Z-306
  • Winter cold spells in Northern Europe and stratospheretroposphere coupling. Tomassini et al; PB-Z-317 CMIP5
  • Mechanisms involved in the amplification of the solar signal in the tropical Pacific Ocean. Misios and Schmidt; PB-Z-411
  • Trends in the Brewer-Dobson Circulation simulated for different model configurations. Bunzel et al; PB-Z-412
  • The response of the middle atmosphere to anthropogenic and natural forcing in CMIP5 simulations with the MPI-ESM. Schmidt et al; PB-Z-416

 

 

WCRP OSC, October 2011. Posters on Stratosphere - Troposphere coupling:


Contact: Elisa Manzini