Aschwanden FASR talk

- What Physics determines the time

scales of radio bursts ?

Characteristic speeds in solar corona:

- Electromagnetic waves, speed of light : c=300,000 km/s

- Electron beam speeds: v_B/c=0.1-0.3

- Alfven waves, Alfven speed: v_A=500-5000 km/s

- Magnetoacoustic waves: c_s < v_MA < v_A

- Shock waves, supersonic speeds: v_sh ~ 300 km/s

- Pressure-driven waves, sound speed: c_s ~ 150 km/s

Characteristic spatial scales in solar corona:

- Acceleration cells and regions: L_acc ~ 100-1000 km

- Flare loops: L_loop ~ 5000-50,000 km

- Metric extent of solar corona: L_metric ~ R_sun ~ 700,000 km