Interdecadal Change in Western Pacific Subtropical High and Climatic Effects
Received date: 2001-07-10
Revised date: 2001-10-10
Online published: 2002-03-25
Supported by
National Key Project for Basic Research, No.G1998040900; National Natural Science Foundation of China, No.40105007
Western North Pacific Subtropical High is a very important atmospheric circulation system influencing the summer climate over eastern China. Its interdecadal change is analyzed in this study. There is a significant decadal shift in about 1979/1980. Since 1980, the Western North Pacific Subtropical High has enlarged, intensified, and shifted southwestward. This change gives rise to an anti-cyclonic circulation anomaly over the region from the South China Sea to Western Pacific and thus causes wet anomalies over the Yangtze River valley. During the summers of 1980-1999, the precipitation is 63.9 mm above normal, while during 1958-1979 it is 27.3 mm below normal. The difference is significant at the 99% confidence level as a t - test shown. The southwestward expanding of the Western North Pacific Subtropical High also leads to a significant warming in the southern China, during the 1980-1999 the summer mean temperature is 0.37oC warmer than that of the period 1958-1979. The strong warming is primarily due to the clearer skies associated with the stronger downward air motion as the Western North Pacific Subtropical High expanding to the west. It is also found that the relative percentage of tropical cyclones in the regions south of 20oN has been decreasing since the 1980s, but that in the regions north of 20oN has been increasing during the same period. The Western North Pacific Subtropical High responds significantly to sea surface temperature of the tropical eastern Pacific with a lag of one-two seasons and simultaneously to sea surface temperature of the tropical Indian Ocean. The changes in the sea surface temperatures are mainly responsible for the interdecadal variability of the Western North Pacific Subtropical High.
GONG Dao-yi, HE Xue-zhao . Interdecadal Change in Western Pacific Subtropical High and Climatic Effects[J]. Acta Geographica Sinica, 2002 , 57(2) : 185 -193 . DOI: 10.11821/xb200202008
[1] Lau K M, Kim K M, Yang S. Dynamical and boundary forcing characteristics of regional components of the Asian summer monsoon. J. Climate, 2000, 13: 2461-2482.
[2] Liu Y M, Wu G X. Reviews on the study of the subtropical anticyclone and new insights on some fundamental problems. Acta Meteorologica Sinica, 2000, 58(4): 500-512.
[刘屹岷, 吴国雄. 副高研究回顾及对几个基本问题的再认识. 气象学报, 2000, 58(4): 500-512.]
[3] Gong D Y, Wang S W, Yang Y W et al. Analysis on the anomalous Western Pacific Subtropical High during the 1990s. Meteorological Monthly, 1998, 24(8): 8-13.
[龚道溢, 王绍武, 杨义文 等. 90年代副高异常的分析.气象, 1998, 24(8): 8-13.]
[4] Kalnay E, Kanamitsu M, Kristler R et al. The NCEP/NCAR 40-year Reanalysis Project. Bull. Am. Meteorol. Soc., 1996, 77: 437-471.
[5] Zhang S Q, Lin X C. The influence of Subtropical High sustained anomaly on flood season rainfall in the middle and lower reaches of the Changjiang River. Meteorological Monthly, 2000, 26(5): 27-31.
[张素琴, 林学椿. 副高持续异常对长江中下游夏季降水的影响. 气象, 2000, 26(5): 27-31.]
[6] Gong D Y, Wang S W, Zhu J H. Surplus summer rainfall along the middle to lower reaches of Changjiang River in the 1990s. Acta Geographica Sinica, 2000, 55(5): 567-575.
[龚道溢, 王绍武, 朱锦红. 1990年代长江中下游地区多雨的机制分析. 地理学报, 2000, 55(5): 567-575.]
[7] Hu Z Z. Interdecadal variability of summer climate over East Asia and its association with 500 hPa height and global sea surface temperature. J. Geophy. Res., 1997, 102:19403-19412.
[8] Gray W M. Global view of the origin of tropical disturbances and storms. Mon. Wea. Rev., 1968, 96: 669-700.
[9] Yang G S, Shi Y F. Changes in the frequencies of tropical cyclones and their relationships to sea surface temperature in the northwestern Pacific. Acta Geographica Sinica, 1999, 54(1): 22-29.
[杨桂山, 施雅风. 西北太平洋热带气旋频数的变化及其与海表温度的相关研究. 地理学报, 1999, 54(1): 22-29.]
[10] Ye Y, Dong B. Interannual change of the severe tropical cyclone activities over the Northwest Pacific. Meteorological Monthly, 1998, 24(7): 29-34.
[叶英, 董波. 西北太平洋强热带气旋活动的年代际变化. 气象, 1998, 24(7): 29-34.]
[11] Yumoto M, Matsuura T. Interdecadal variability of tropical cyclone activity in the western north Pacific. J. Metoro. Soc. Japan, 2001, 79(1): 23-35.
[12] Chen M, Zheng Y G, Tao Z Y. An analysis on tropical cyclones' climatic feature in the western north Pacific for 1949-1996. J. Tropical Meteorology, 1999, 15(1): 10-16.
[陈敏, 郑永光, 陶祖钰. 近50年西北太平洋热带气旋气候特征的再分析. 热带气象学报, 1999, 15(1):10-16.]
[13] Regional Specialized Meteorological Center - Tokyo Typhoon Center. Tropical cyclone tracks in the western North Pacific 1951-1990. Japan Meteorological Agency, 1992, Tokyo, 192.
[14] Chen X F, Chao S Y. The jump of climate change of typhoon activities. J. Tropical Meteorology, 1997, 13(2): 97-104.
[陈兴芳, 晁淑懿. 台风活动的气候突变. 热带气象学报, 1997, 13(2): 97-104.]
[15] Chang C P, Zhang Y S, Li T. Interannual and interdecadal variations of the East Asian summer monsoon and tropical Pacific SSTs. Part I: Roles of the subtropical ridge. J. Climate, 2000, 13: 4310-4325.
[16] Angell J K. Comparison of variation in atmospheric quantities with sea surface temperature variations in the equatorial eastern Pacific. Mon. Wea. Rev., 1981, 109: 230-243.
[17] Gong D Y, Wang S W. The response of global subtropical highs to the Equatorial Eastern Pacific SST Anomaly. Acta Oceanologica Sinica, 1998, 20(5): 44-54.
[龚道溢, 王绍武. 南北半球副热带高压对赤道东太平洋海温变化的响应. 海洋学报, 1998, 20(5): 44-54.]
[18] Huang R H, Wu Y F. The influence of ENSO on the summer climate change in China and its mechanism. Adv. Atmos. Sci., 1989, 6: 21-33.
[19] Nitta T. Convective activities in the tropical western Pacific and their impact on the Northern Hemisphere summer circulation. J. Meteor. Soc. Japan, 1987, 65: 373-390.
[20] Kistler R, Kalnay E, Collins W et al. The NCEP-NCAR 50-year Reanalysis: Monthly means CD-ROM and documentation. Bull. Am. Meteorol. Soc., 2001, 82(2): 247-267.
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