THE COSMIC RAY FORBUSH DECREASES DURING THE COMBINED OBSERVATIONS IN 1988

In this paper the relationship between the solar flare and the variation of cosmic ray intensity is studied during the combined observations in 1988. The results are similar to those that we got before. Statistically, only the flares of importance 3 and that of importance 2 but with duration>1.5 hours can significantly disturb the cosmic ray intensity. The disturbance has the north-south and east-west asymmetries, depending on the flares position. After analysing these events, it can be seen that a bright flare of importance 1 may induce remarkable Forbush Decrease, if it has long duration enough and is strong X-ray flare.