Diurnal Variation of Convective Activity and Precipitable Water over the "Semi-Basin" : Preliminary Study on the Mechanism Responsible for the Evening Convective Activity Maximum
Diurnal Variation of Convective Activity and Precipitable Water over the "Semi-Basin" : Preliminary Study on the Mechanism Responsible for the Evening Convective Activity Maximum
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“半盆地”对流活动与降水量日变化：晚间对流活动最大值形成机制的初步研究
DOI：
10.2151/jmsj.80.439
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发表时间：
2002
影响因子：
3.1
通讯作者：
Takahiro Miki
中科院分区：
文献类型：
--
作者：
H. Iwasaki;Takahiro Miki
利用水汽辐射计、C波段雷达和探空仪资料研究了夏季对流活动日变化与可降水量的关系。“半盆”对流活动表现出明显的日变化，在15-17JST和19-20JST出现双峰，ShowAlter稳定度指数(SSI)由早到晚呈下降趋势，这是由于热力诱导的局地环流导致低层水汽增加所致。当可降水量表现出明显的日变化时，夜间对流活动最大值(19-20JST)明显，积雨云有在山南和以东的有限区域发展的趋势。哈鲁纳。平均而言，对流活动最大值出现在可降水量最大值之前约1小时，当可降水量在早(晚)时达到最大值时，积雨云也在早(晚)时形成。此外，根据对流活动和可降水量的日变化结果，讨论了“半盆”夜间对流极大值的形成机制。
The relationship between the diurnal variation of convective activity and precipitable water was examined in summer seasons using water vapor radiometer, C-band radar and radiosonde data. Convective activity over the “semi-basin” exhibited a diurnal variation with dual peaks at 15-17 JST and 19-20 JST, and the SSI (Showalter Stability Index) decreased from morning to evening due to the increase of water vapor in the lower layers associated with a thermally induced local circulation. When precipitable water exhibited a pronounced diurnal variation, the evening convective activity maximum (19-20 JST) was evident and cumulonimbus clouds had a tendency to develop over a limited region south and east of Mt. Haruna. On average the convective activity maximum occurred about an hour before the precipitable water maximum, and when precipitable water reached a maximum at an early (late) time, cumulonimbus clouds also formed at an early (late) time. Furthermore, the mechanism responsible for the evening convective maximum over the “semi-basin” is discussed, based on the results of the diurnal variation of convective activity and precipitable water.