Abstract

Interrelationship between heavy rainfalls and related with low-level jets(LLJ) is analyzed by using fifty cases of heavy rainfall events occurred over the Korean peninsula from 1992 to 2001. Those cases are classified with four synoptical features. There are 32% chances that the low pressure exist in heavy rainfall over than 150 mm per day case by case. Secondly Changma front and front zone account for 28% of all cases. The ratio of marine tropical boundary type and trough type record 22% and 18% respectively. The moist and warm south-westerly winds associated with low-level jets have been induced convective instability and baroclinic instability. Therefore, heavy rainfall due to the approach of a low pressure occurred at September and before Changma. During the period of Changma, this type has been happened heavy rainfall when low pressure and stationary front has vibrated south and north. Changma type has longer the duration time of precipitation than other types. Third type, located with marine Tropical boundary, have mainly rained in August and September. The last trough case locally downpoured in short time with developing cell. The occurrence low-level jets related to heavy rainfall has increased over 12.5 m/s wind speed. The result is that 43 heavy rainfalls out of 50 cases reach peak at the time of maximum precipitation intensity. Also, the variation of wet number and K-index corresponded with the variation of wind speed. It is found that the number of frequency of low-level jets with southwestward direction has been increased and these jets are mainly passed from the southwest toward to the northeast of the Korean peninsula in that time.

Keywords

• 집중호우;
• 몬순;
• 장마;
• 중규모 대류계;
• 종관규모;