Science goals

  1. Investigate distributions of microphysical, optical and radiative properties of cirrus clouds to better understand and more accurately quantify their climate impact
  2. Study cirrus properties, lifetime, ambient conditions (updraft, RHI, aerosol load) in meteorological regimes typical for high latitudes → focus in-situ cirrus
  3. Validate satellite products and ground-based observations and evaluate advanced cloud models
  4. Assess cirrus and contrail cirrus predictability → Contrail avoidance demo
  5. Directly observe contrail cirrus and investigate differences between contrail and natural cirrus
  6. Quantify an aviation effect on cirrus


Cirrus at high and mid latitudes
  • Are cirrus clouds adequately represented in climate models? Convection? Mixed phase clouds? → What is the related uncertainty in their climate impact?
  • Do weather models underestimate/overestimate water vapor and RHi in cirrus regions, in the upper troposphere and in the lower stratosphere?
  • What is the role of clouds for the Arctic amplification?
  • Are Arctic cirrus observations from Calipso real?
  • Process studies: Convection, WCB, ridge cirrus, high pressure cirrus, leewave cirrus
Cirrus cast a shadow on lower clouds
Aviation cirrus
  • Do contrails significantly modify microphysical, optical and radiation effect on cirrus in mid-latitudes?
  • Do cirrus properties in regions with high air traffic differ from cirrus in regions with low airtraffic?
  • Is there an aviation impact on cirrus (in addition to contrails)?
  • Do we understand the daily cycle of cirrus radiative effects (LW/SW/Net)?
  • Is there a distinguishable anthropogenic effect on cirrus (compared to e.g. BLUESKY 2020, ML-CIRRUS 2014)?