are rather subtle and involve global coupling in the outer regions.

Throughout the disk evolution from quiescence to outburst, the outermost disk (around $10^{11}$ cm) stays in the cold, neutral state at $\log T_{\rm eff}$ $\lta$ 3.4, or $\log T_{\rm c}$ $\lta$ 3.55. After maximum light, the cooling wave is initiated around $6\times 10^{10}$ cm. The resulting outward diffusion of the surface density results in a small increase in the temperature at larger radii. The molecular stagnation (discussed in subsection 4.2) and consequent higher temperature of the outer regions due to the indirect irradiation affects the behavior of the inner regions. The regions just interior to the molecular-stagnation region can not simply drop into the cool state, because there is now some resistance to the outward diffusion of matter that is attendant to the non-irradiated cooling wave. Instead, the decline in temperature after the onset of the cooling instability is halted in the nearly constant temperature intermediate ionization stagnation state, as shown in figure 7.

After the outburst maximum, the X-ray novae have exhibited additional features in the decay, such as “reflares" 50–80 d after the maxima, the “second maxima" a few hundred days later, and subsequent “mini-outbursts" before returning 