ANALYSIS OF THE CHARACTERISTICS OF THE LAND-SEA BOUNDARY LAYER OVER THE DIANBAI AREA DURING THE ACTIVE AND INACTIVE PERIODS OF SOUTH CHINA SEA SUMMER MONSOON IN 2012
-
摘要: 利用2012年6—9月南海夏季风期间的近海海洋气象观测平台 (海上平台站) 和电白国家气候观象台 (电白站) 的地面气象站资料，气象塔资料以及GPS探空资料对海上平台站和电白站两站在季风活跃期和非活跃期的大气边界层结构特征进行研究分析。结果表明，活跃期与非活跃期两地的大气边界层结构特征有明显差异。(1) 在活跃期两站近地层风向全天由东南风主导，风速较大，且两站均出现连续降水，受云系和降水的影响，与非活跃期相比，电白站近地层日平均气温降低约为2 ℃；非活跃期两站风向全天无规则变化，且风速值小。(2) 在活跃期大气边界层内风向均为一致的东南风，风速较大，200 m以上的风速均大于8 m/s，而在非活跃期大气边界层内风速较小，风向变化较大，同一时刻不同高度的风向差可达180 °。(3) 在季风非活跃期混合层高度最高可达937 m，而在活跃期，受降水和云系的影响混合层高度明显降低，最大高度仅为700 m左右。(4) 活跃期受连续降水影响，大部分时刻的大气边界层内相对湿度大于80%。由此可见在季风活跃期与非活跃期不仅海陆气能量交换发生变化，大气边界层结构特征也有显著变化。Abstract: The characteristics of the land-sea atmospheric boundary layer during the active and inactive periods of the South China Sea Summer Monsoon (SCSSM) are analyzed by using the observation data obtained from the Dianbai meteorological station and the Marine Meteorological Science Experiment Base at Bohe from June to September in 2012. It is found that the structure of the atmospheric boundary layer in the active and inactive periods of SCSSM differs significantly not only above the land but also over the sea. (1) In the active period, A southeast wind dominates during the whole day, which is observed at both the sea and land sites, and the wind speed is relatively high. In contrast, the wind direction in the inactive period changes irregularly, and the wind speed is smaller than that in the active period. Moreover, in the active period, continuous precipitation is observed. As a result, the average daily temperature in the active period within the surface layer over land is reduced by approximately 2 ℃ than that in the inactive period; (2) Based on the sounding data, during the active period, a prevailing southeast wind exists in the boundary layer, and the wind speed of larger than 8 m/s persists above the altitude of 200 m. However, during the inactive period, the wind speed is relatively small, and the wind direction changes frequently. The deviation of the wind direction between the upper and lower layers of the boundary layer reaches up to 180 degrees in the inactive period. The temporal behavior of the potential temperature vertical profile in the land-type boundary layer is also analyzed. It is shown that the boundary layer height reaches the maximum of 937 m in the inactive period. In contrast, due to the existence of the precipitation and the clouds during the active period the height of the mixing layer decreases heavily. The highest boundary layer found in the active period has the thickness of only about 700m. The sounding data also shows that the relative humidity in the boundary layer during the active period is mostly larger than 80%, which is attributed to the continuous rainfall. The analysis in the present study reveals that the land-sea energy exchange behaves differently in the active and inactive periods of SCSSM. Besides, the characteristics of the structure of the atmospheric boundary layer strongly change as well.
-
图 2 电白站（a）与海上平台站（b）在非活跃期 (6月29日) 的气温、相对湿度和降水的日变化（a、b）和电白站（c）与海上平台站（d）在活跃期 (7月1日) 的气温、相对湿度和降水的日变化 (c、d)
图 3 电白站 (a) 和海上平台站 (b) 在非活跃期 (6月29日) 的风向、风速和降水的日变化（a、b）及电白站 (c) 和海上平台站 (d) 在活跃期 (7月1日) 的风向、风速和降水的日变化（c、d）
-
[1] TAO S, CHEN L. A review of recent research on the East Asian summer monsoon in China[J]. Monsoon Meteorology, 1987: 60-92. [2] WANG B. The Asian Monsoon[M]. New York:Springer/Praxis Publishing Co, 2006:787. [3] 竺可桢.东南季风与中国之雨量[J].地理学报, 1934, 1(1): 1-27. [4] 涂长望, 黄仕松.中国夏季风之进退[J].气象学报, 1944, 18(1): 82-92. [5] 丁一汇.中国的夏季风降雨及其区域特征[M]//亚洲季风.北京:气象出版社, 1994: 76-83. [6] 郭其蕴.季风与中国旱涝[M]//亚洲季风.北京:气象出版社, 1994: 65-74. [7] 冯瑞权, 王安宇, 吴池胜, 等.南海夏季风建立的气候特征Ⅰ——40年平均[J].热带气象学报, 2001, 17(4): 345-354. [8] 林建恒, 王安宇, 冯瑞权, 等.南海夏季风维持期的气候特征Ⅰ——40年平均[J].热带气象学报, 2005, 21(2): 113-122. [9] 吴尚森, 梁建茵, 李春晖.南海夏季风强度与我国汛期降水的关系[J].热带气象学报, 2003, 19(1): 25-36. [10] 连帆, 巩远发, 刘佩佩, 等.基于QuikSCAT资料的江淮流域旱涝年南海季风变化特征[J].热带气象学报, 2014, 20(6): 1 137-1 145. [11] 吕心艳, 张秀芝, 陈锦年.东亚夏季风南北进退的年代际变化对我国区域降水的影响[J].热带气象学报, 2011, 27(6): 860-868. [12] 李香淑, 郭学良, 付丹红, 等.南海季风爆发期间中尺度对流云带演变特征与持续性加强的机理研究[J].大气科学, 2011, 35(2): 259-271. [13] LIN S C, KUEH M T. A modeling diagnosis of the development of mesoscale convective systems over the South China Sea during the summer monsoon onset in 1998[J]. Terrestr Atmos Ocean Sci, 2003, 14(4): 369-400. [14] LAU K-M, DING Y H, WANG J T, et al. A report of the field operations and early results of the South China Sea Monsoon Experiment (SCSMEX)[J]. Bull Amer Meteorol Soc, 2000, 81(6): 1 261-1 270. [15] DING Y H, LI C, LIU Y. Overview of the South China Sea Monsoon Experiment[J]. Adv Atmos Sci, 2004, 21(3): 343-360. [16] 柳艳菊, 丁一汇.南海季风爆发前后大气层结和混合层的演变特征[J].气候与环境研究, 2000, 5(4): 459-468. [17] 闫俊岳, 姚华栋, 李江龙, 等. 2000年南海季风爆发前后西沙海域海-气热量交换特征[J].海洋学报, 2003, 25(4): 18-28. [18] 闫俊岳, 唐志毅, 姚华栋, 等. 2002年南海季风爆发前后西沙海区海-气通量交换及其变化[J].地球物理学报, 2005, 48(5): 1 000-1 010. [19] 孙启振, 陈锦年, 闫俊岳, 等. 2008年南海季风爆发前后西沙海域海气通量变化特征[J].海洋学报, 2010, 32(4): 12-23. [20] 邓雪娇, 李春晖, 毕雪岩, 等.南海季风建立前后珠江三角洲的陆气热量交换与热力大气边界层结构特征[J].气象学报, 2007, 65(2):280-292. [21] HUANG H J, MAO W K. The South China Sea monsoon experiment-boundary layer height (SCSMEX-BLH): experimental design and preliminary results[J]. Mon Wea Rev, 2015, 143(12): 5 035-5 053. -
下载:
点击查看大图
图(7)
计量
- 文章访问数: 1038
- HTML全文浏览量: 51
- PDF下载量: 483
- 被引次数: 0
粤公网安备 4401069904700003号