3: Particle Precipitation

What are the effects of particle precipitation on the atmospheric system?

  • How are the middle atmospheric chemistry and temperature directly influenced by energetic particle precipitation (EPP)?
  • How well are various types of EPP parameterized in current coupled chemistry-climate models?
  • How does the EPP-produced chemistry drive the dynamics: What effect do the radiatively and chemically active species produced during EPP have on perturbing the large-scale dynamics of the polar regions, including planetary waves?
  • How do the dynamics drive the EPP-produced chemistry: What role do tides and planetary waves play in the horizontal transport of EPP-influenced species to/from the polar regions?
  • How can EPP affect surface weather and climate?

BCSS will bring together space and atmospheric scientists with the expertise needed to acquire, analyse and interpret the data in order to unravel the complex relationship between EPP and their atmospheric effects. In this investigation, we propose to use ground-based and global satellite measurements of particle flux, composition, temperature and winds to determine the direct effects of EPP throughout the atmosphere. In particular, the POES satellites provide long time series of EPP from keV to relativistic energies (Sandanger et al., 2009). These observations will be coupled to whole-atmosphere, chemistry-climate models (e.g. WACCM) to connect the effects seen in different atmospheric regions; to examine the coupling mechanisms; to determine the interplay of photo-chemistry and dynamics; and to examine the coupling of these EPP-effects to the climate system. The direct effects of EPP on composition, temperature and winds will be better parameterized through improved treatment of ionisation rates and electron precipitation in chemistry-climate models (Semeniuk et al., 2011). Through this strong synergy of observations, modelling, and collaboration with the Bjerknes Centre for Climate Research, the effect of reactive species on the radiative and dynamic balance of the polar regions and the lower atmosphere will be quantified. This will provide a more complete understanding of Earth’s climate and possible natural variations that may enhance or mask the effects of anthropogenic climate change.

Go to Overview to read more about the G3 work.