CAJ | 학술논문

利用2007年6月1日-8月31日云南省闪电定位系统监测的云-地闪电资料与NCEP/NCAR再分析资料中的相对湿度物理量,分析了云南省闪电活动时相对湿度的结构特征.结果表明:云南省闪电活动除具有夏季是高发期且日分布具有呈一峰一谷变化特征,在时间演变上还具有不均匀和阶段性的特点,这与特定的大气相对湿度环境条件密切相关;云南省闪电活动一般发生在相对湿度乖直结构具有低层湿度不高、中层高湿、高层又逐渐变干的环境大气中,大约在中层700 hPa以下相对湿度随高度增加,逐渐在中层形成高湿层,中层以上相对湿度又随高度减小,低层湿度不高、中层高湿、高层偏干的环境相对湿度条件非常有利于雷暴天气的发生和闪电的形成,一方面中层以下水汽随高度增加有利于水汽的上升运动和云的凝结形成,另一方面中高层水汽随高度迅速减小有利于形成上干下湿的大气对流不稳定,促使对流云进一步发展,从而产生闪电活动;低层相对湿度在40%～75%之间,中层600～700 hPa之间相对湿度较高,可达80%以上,一般为90%～95%,中层湿层越深厚,闪电过程越强烈,在高层250～400 hPa左右相对湿度减小到35%～60%之间.
이용2007년6월1일-8월31일운남성섬전정위계통감측적운-지섬전자료여NCEP/NCAR재분석자료중적상대습도물리량,분석료운남성섬전활동시상대습도적결구특정.결과표명:운남성섬전활동제구유하계시고발기차일분포구유정일봉일곡변화특정,재시간연변상환구유불균균화계단성적특점,저여특정적대기상대습도배경조건밀절상관;운남성섬전활동일반발생재상대습도괴직결구구유저층습도불고、중층고습、고층우축점변간적배경대기중,대약재중층700 hPa이하상대습도수고도증가,축점재중층형성고습층,중층이상상대습도우수고도감소,저층습도불고、중층고습、고층편간적배경상대습도조건비상유리우뇌폭천기적발생화섬전적형성,일방면중층이하수기수고도증가유리우수기적상승운동화운적응결형성,령일방면중고층수기수고도신속감소유리우형성상간하습적대기대류불은정,촉사대류운진일보발전,종이산생섬전활동;저층상대습도재40%～75%지간,중층600～700 hPa지간상대습도교고,가체80%이상,일반위90%～95%,중층습층월심후,섬전과정월강렬,재고층250～400 hPa좌우상대습도감소도35%～60%지간.
Using monitored cloud-ground lightning data of lightning detection system in Yunnan Province and relative humidity parameter in NCEP/NCAR data from 1 June to 31 August in 2007, structural character-istics of atmospheric relative humidity during lightning activity are analyzed. The results show that light-ning activity in Yunnan is most frequent in summer because of high temperature and high humidity, and there's a daily apex which appears from 16:00 to 17:00 and a valley which appears from 08.00 to 11:00 be-cause of daily variation of solar radiation. The lightening activity is uneven and discontinuous on day-to-day variation because of environmental conditions of atmospheric relative humidity.Some specific environmental humidity conditions are necessary for lightening activity. Too high hu-midity may restrain ascending motion of convective development, while low humidity is insufficient for convective cloud to develop. Moreover, convective development and intensification are aroused, and con-vective cloud developing upwards is urged by some dynamic triggering condition when unstable energy runs up to a certain extent. When electric field intensity reaches to a certain extent, the thunder phenomenon occurs.Lightning activity in Yunnan usually happens in the typical environmental atmosphere with certain vertical configuration: The relative humidity is not high at 850 hPa, but at 700 hPa it's very humid and then becomes dry at upper layers. The relative humidity increases with height below the 700 hPa, forming high moist region at the middle layer and deceases above it. This environmental condition of relative hu-midity is in favor of thunderstorm weather occurrence and thunder formation. First, relative humidity in-crease below 700 hPa is favorable for ascending motion of water vapor and cloud formation. Second, dry atmosphere at upper layers and moist atmosphere at lower layers cause convective instability so that con-vective cloud may be urged to develop and promote lightning activity. When lightening occurs, relative hu-midity at low layer is about 40%-75%, at middle layers of 600-700 hPa it is above 80% and usually rea-ches up to 90%-95%, and the humidity decreases to about 35%-60% at upper layers of 250-400 hPa.It is also found that deeper middle moist layer will probably result in stronger thunder process.