Presentation on theme: "Mælkevejen og Jordens klima Henrik Svensmark, Dansk Rumforskningsinstitut Email email@example.com Københavns Universitet, 2002."— Presentation transcript:
1Mælkevejen og Jordens klima Henrik Svensmark, Dansk Rumforskningsinstitut Email firstname.lastname@example.org Københavns Universitet, 2002
2Satellite Failures due to Space Weather Effects Anomalies due to spacecraft surface and internal charging (Marecs, ECS, Meteosat, TELE-X,…..)Latch-up induced failures (ESR-1, PRARE, Equator-S,…..)SEU’s in linear circuits…(Anik 1 &2)Solar Array problems/degradation (Tempo, PanAm, ECS,….)More recent satellite failures:Telestar 401TV links etc..Galaxy IVsilenced 80% of pagers in North AmericaMore than 12 satellites lost due to Space Weather EffectsLast 4 years space losses may have exceeded $500 millionCommercial interests often do not allow anomaly reporting.
3Damage to transformers Damage to a transformer at a power plant Delaware, New JerseyPrice: 10 mill USDRepair can take up to 1 year.In this particular case they were lucky to find a used one from a shut down plant. Took only 6 weeks to restoreSweden: simultaneous power loss in six 130 kV power distribution linesChicago: Five transformers in the Chicago area failed due to elevated geomagnetic activity
4New Particle formation: Observations and Theory Observed nucleation rates are much larger than predicted by classical binary (H2SO4+H2O) nucleation theoryThe functional dependence of the observed nucleation rate of [H2SO4] is much weaker (~ [H2SO4]2 )than predicted by classical binary (H2SO4+H2O) nucleation theory (~ [H2SO4]10 )Measured growth rates of freshly formed nanoparticles are about a factor of 10 higher than can be explained by H2SO4 and its associated H2O and NH3
5Micro-physics: Why in the lower part of the atmosphere? DGt: Time to grow from rc to r*rcrir*rT (sek)Ion-pair/cc/sek400300200100t ~ 200 sekfor [H2SO4] = pr cc
6enhanced aerosol formation caused by ionisation Experimental evidence ofenhanced aerosol formation caused by ionisationNatural level of ionisationArtificial airN2:O2 = 4:1SO2 = 300 ppbC2H4 = 100 ppbO = 160 ppbVohra et al., Atmos. Environment, 18, 1653 (1984)
7Cosmic ray variations ionisation and aerosol formation Based on Numericalstudies by Yu, 2001