Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Do you really want to delete this prezi?
Neither you, nor the coeditors you shared it with will be able to recover it again.
Make your likes visible on Facebook?
Connect your Facebook account to Prezi and let your likes appear on your timeline.
You can change this under Settings & Account at any time.
Transcript of Multi-scale modelling
Solving a physical problem which have important features at multiple scales
from nanoseconds to centuries
from nanometers to several kilometers
Quantum mechanical model
From quantum mechanics to globlal climate
Largest source of uncertainties in global climate models (GCM)
How particles are formed in the atmosphere still unclear
Cloud Condensation Nuclei
Classical Nucleation Theory
neutral air ions spectometer
Global Climate models
Too big for QM
PSM can see them!!!!
Formation free energies of different clusters
Combine CNT and QM
Atmospheric Cluster Dynamics Code
Adding the last scale
Hyytiälä SMEAR II station in Finland
continuous aerosol particle size distribution measurements since 1996
trace gases, meteorology, fluxes
CLOUD chamber experiment in CERN (2009-)
sulphur dioxide converted to sulphuric acid by UV light + water
electric field to clear all ions
natural ionization by galactic cosmic rays (GCR)
CERN pion beam to produce extra ions
other atmospheric vapours: ammonia and dimethyl amine
J Kirkby et al. Nature 476, 429-433 (2011)
" However, for typical boundary-layer ammonia mixing ratios, below about 1p.p.b.v., ternary nucleation of NH3–H2SO4–H2O, with or without ions, is unable to explain atmospheric observations. This implies that other species, most probably organic compounds, are necessary for boundary-layer nucleation."
Galactic Cosmic Rays role
presence of DMA can explain observations
Link charged and neutral CD
GCR less important if enough base is present
Complement MS techniques
Too small for CNT
Too small for NAIS
MS only charged
Dr. I.K. Ortega
University of Helsinki
Evaporation rate = 2.2 E 10 1/s
Life time 0.22 ns
sampling time microseconds