摘要
利用2004-2017年静止气象卫星Kalpana-1的高分辨率(空间分辨率0.25°×0.25°,时间分辨3 h一次,每天8个时次)射出长波辐射(Outgoing Longwave Radiation,OLR)资料,分析了青藏高原和南亚地区夏季对流的日变化特征,并结合ERA-Interim分析资料和中国常规降水观测资料对2006年和2007年的对流活动异常、垂直速度异常、降水异常三者的联系进行研究。结果表明:(1)青藏高原和南亚地区夏季6-9月有非常明显的对流活动,其中在对流活动最强的盛夏7-8月,青藏高原中部和东南部、印度半岛东北部、孟加拉湾到中南半岛都有大范围的强对流区,强度最强的对流区OLR平均最小值低于190 W·m^(-2)。(2)青藏高原和南亚地区对流活动日变化特征明显。其中青藏高原中南部、青藏高原东南部、印度半岛东北部和中南半岛南部地区都在09:00(世界时,下同)左右开始出现OLR低于210 W·m^(-2)的强对流区,在12:00左右对流活动强度达到最强,对流活动均可持续到次日凌晨。孟加拉湾东海岸全天都有明显的对流活动,在09:00和21:00的2个时次达到最强。对比青藏高原、南亚和孟加拉湾地区,青藏高原中南部地区的对流日变化最为显著,陆地区域对流日变化是一个周期,而孟加拉湾东岸地区的日变化有两个周期。(3)对比分析2006年和2007年7-8月青藏高原地区和中国西南地区的OLR异常变化与垂直速度和降水异常可以发现,高分辨率的OLR负(正)距平表示的异常强(弱)对流与异常上升(下沉)运动及异常多(少)的降水三者之间密切相关,可以用来表征青藏高原地区对流活动的变化特征,以弥补其观测资料的不足。
Based on the high-resolution(the spatial resolution is 0.25°×0.25°,the temporal resolution is once every 3 hours,8 times a day)outgoing longwave radiation(OLR)data of the geostationary meteorological satellite Kalpana-1 from 2004 to 2017,the characteristics of convection diurnal variations over the Qinghai-Xizang Plateau and South Asia area in summer are analyzed.Combined with ERA-Interim analysis data and the observed precipitation data in China,the relationship among convective activity anomaly,vertical velocity anomaly and precipitation anomaly in 2006 and 2007 is studied.The results show that:(1)In June to September of summer,especially from July to August,the severe convection mainly occurs in the central and southeastern Qinghai-Xizang Plateau,the northeastern Indian Peninsula,the Bay of Bengal and the Indochina Peninsula.Minimum value of mean OLR in the strongest convection area is less than 190 W·m^(-2).(2)The characteristics of convection diurnal variations over the Qinghai-Xizang Plateau and South Asia area are obvious.In the central-southern and the southeastern Qinghai-Xizang Plateau,the northeastern Indian Peninsula and the southern Indochina Peninsula,the strong convective areas with OLR below 210 W·m^(-2)begin to appear around 09:00(UTC,the same as after),the strongest convective activity takes place at 12:00,and the convective activity can continue until the next morning.However,in the East Coast of the Bay of Bengal,the obvious convective activity occurs throughout the day and reaches its twice maximum at 09:00 and 21:00.Compared with convection diurnal variations over the Qinghai-Xizang Plateau,South Asia area and the Bay of Bengal,the land areas have one cycle one day,the East Coast of the Bay of Bengal has two cycles one day,and the strongest diurnal oscillation occurs in the centralsouthern Qinghai-Xizang Plateau.(3)A comparative analysis of OLR,vertical velocity and precipitation anomaly over the Qinghai-Xizang Plateau and Southwest China from July to August in 2006 and 2007 shows that
作者
康潆文
巩远发
KANG Yingwen;GONG Yuanfa(School of Atmospheric Sciences,Chengdu University of Information Technology/Sichuan Key Laboratory of Plateau Atmosphere and Environment,Chengdu 610225,Sichuan,China;Benxi Manchu Autonomous County meteorologic bureau,Benxi 117100,Liaoning,China)
出处
《高原气象》
CSCD
北大核心
2021年第3期472-485,共14页
Plateau Meteorology
基金
国家自然科学基金项目(41775079)
国家自然科学基金重点项目-区域创新发展联合基金(U20A2097)。
关键词
青藏高原
射出长波辐射(OLR)
对流日变化
Qinghai-Xizang Plateau
Outgoing Longwave Radiation(OLR)
convection diurnal variations
