Soft X-ray observations of global waves Khan-Aurass 2002 Narukage et al Hudson et al. 2002

Solar shock: Type II burst

Moreton-Ramsey wave and EIT wave Thompson et al., 2000

X-ray observation of a global wave Wave propagation tells us about coronal structure The innermost (earliest) motions tell us about the flare process itself

May 6, 1998 FOV 10 arc min

SOHO/ EIT

Uchida’s 1968 model

S.W. Uchida A.R.

What caused the blast wave? In principle we can see all of the process in soft X-rays The earliest manifestation of the May 6 wave is close (10 4 km) to the flare core But… it is significantly displaced from the core

Implosion conjecture At low , the coronal energy is purely B 2 /8  During a flare, there’s no time for energy transport through the photosphere Therefore, some field lines must shorten

Isomagnetobars Closed field lines Open field lines How low-  implosions must work