Some Key Concepts in Solar Terrestrial Physics • What is the solar power source? : fusion (pp CNO cycles) • How do we know this? : neutrinos and fit to Standard Solar Model • Summarize the Standard Solar Model : Hydrostatic equilibrium and other assumptions gives 4 ordinary differential equations and 4 unknowns • Why does energy transport by convection dominate in the Convection Zone? :plasma becomes opaque to photons because atoms begin to form as T drops. • Describe the Solar Spectrum : black body spectrum at 6000 oK dominates • What physical phenomenon allows us to study Solar Seismology? : from Doppler shift can study photosphere motions result in Sound waves and Buoyancy oscillations: Standing Waves • What are some of the main features of the Photosphere? : sunspots, granules and supergranules. T ~ 6,000 oK, • What is the Frozen in Condition for magnetic fields and plasma? :plasma moves with magnetic field • What is a plasma? :ionized gas • Discuss the concepts of temperature, density and basic response time of plasma : describe plasma frequency and Debye Length (plasmas shield E-fields from net charged regions) • What is the real length of the sunspot cycle? : about 22 years • Is the 'solar constant' really constant? : no the Luminosity is NOT constant • Since the Corona is above the photosphere, it must be cooler, right? : no it is HOT: T ~ 106 K. CME (coronal Mass Ejections) • What is the source for the Solar Wind? : main source: coronal holes. Supersonic (super Alfvenic) • What is the so called Garden hose angle for Interplanetary magnetic field : about 45o at Earth, depends on speed of solar wind and rotation rate of sun • What is the Heliosphere? :extent of the solar wind, which extends to the Interstellar medium. • What is the Bow Shock? :Solar Wind - Earth systems interaction: first: Bow Shock • Describe the basic motion of charged particles : Guiding Center Motion: Drift Equations • Describe the upstream region of the Earth’s Bow Shock : upstream region - unique in shock physics. T increase, B increase, Density increase, velocity decrease at shock • Describe some important Magnetosphere interactions :Most solar wind plasma reflects off earth's B-field and flows around. Chapman-Ferraro current • What does the Reconnection theory tell us : puts whole magnetosphere in motion: magnetospheric convection, B-field has to diffuse out of plasma: MHD breakdown: particle acceleration/heating • Give some Evidence for reconnection : tangential E continuous, and solar wind particles in polar ionosphere • Describe the Magnetotail : hundreds of Re (earth radii) in length. Reconnection in tail closes cycle and injects heated plasma into inner magnetosphere • What is the motion of a Trapped energetic particle in dipole B-field? : Gyration, Bounce and Drift • Describe the Radiation Belts • What is the Ring current? : 2nd largest energy reservoir in magnetosphere (what is largest?) • What are the main properties of the Plasmasphere? : high density, low energy. Corotation • Discuss the importance of Field aligned currents : e.g. Auroras • Coupled system: How do the Magnetotail and ionosphere interact? : substorms: cross tail current interruption • putting it all together: Alfven shielding; current systems; cold/hot plasma drifts • Ionosphere: D, E and F regions. Currents in E-region can be dissipation less .