Presentation on theme: "Sun-Earth Connections Effects of solar phenomena on Earth."— Presentation transcript:
Sun-Earth Connections Effects of solar phenomena on Earth
The sun: our beautiful, peaceful, life-giving star.
What do we get from the sun? Light Heat Photosynthesis >>> LIFE! UV for tanning, sunburn & skin cancer Ozone layer provides some UV filtering A steady flux of charged particles Most deflected by Earth’s magnetic field
Diversion: find the dot. What is it?
Not a sunspot, but the shuttle!
The spotty sun
Inside the sun, and other stars like the sun Three main interior zones: 1. Core, where fusion happens 2. Radiative Layer 3. Convective Layer Surface Atmosphere
80,000 K1,000,000 K
1,500,000 K 2,000,000 K
A roiling mass of plasma…
SUPERCOMPUTER SUNSPOT Researchers at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, have created an unprecedented 3D supercomputer model of a sunspot. The result is not only scientificially informative, but also a thing of beauty:
What goes on below the surface subsurface cross section of two sunspots. Lighter/brighter colors = stronger magnetic field First glimpse below the visible surface to understand underlying physical processes spotvisuals.shtml spotvisuals.shtml
The sun affects the Earth environment November 6, 1997: 12:36 UT
Coronal mass ejection (CME)
Interacting magnetic fields (not to scale!)
Major white light flare
No big deal. Right? Wrong. Major solar storm can disrupt or destroy power grids on a large scale 1989 Quebec event offers a hint of what could happen Sun is the quietest now as it has been for the last 100 years Present technology developed during this quiet period Doubtful if it could survive a Carrington event
Richard Carrington’s 1859 sunspot & flare drawing
Carrinton event Giant spots, flare, CME Most severe space weather event in history Eight days long Stunning aurorae at equatorial latitudes Global telegraph network disrupted, operators suffered electric shocks Magnetometers driven off scale
From solar wind to solar storm High-energy charged particles leave the sun as the solar wind all the time CMEs release billion-tonne blobs of it If it strikes*, it changes configuration of Earth’s magnetic field Induces huge DC currents in power grid transmission lines swamps transformers, which melt This was the 1989 Quebec event
A Carrington event today Modern high-voltage, interconnected grid is very vulnerable Grids are efficient antennas, channeling huge DC to transformers, killing them All developed countries depend on grid for power, water & sewage, transportation, emergency services, navigation, communications, etc. Increasingly we rely on vulnerable satellite technology too
NASA & NAS worst-case study predicts: 15 minutes warning 300 key transformers gone in 90 seconds Catastrophic loss of critical infrastructure Health care systems collapse in 3 days Coal-fired power gone in 30 days Millions of lives lost 4-10 years to recover
The good news: With enough warning utilities and space programs can take precautions to avoid worst damage ACE satellite monitors the sun, BUT: ACE is aging and needs replacing Hard to inspire action in preparation for something that hasn’t happened in living memory “Unlikely” does not equal “won’t happen” Next solar max in 2012 predicted to be big