Abstract
The major features of the south-westerly low-level jet (LLJ) in the lower troposphere over Southeast China and its climatic impacts are investigated by using FNL reanalysis data and observational precipitation data. Results show that LLJ mainly occurs in spring and summer and the occurrence frequency of LLJ over southeast China has significant diurnal cycle, most LLJ occur in the nighttime (0200 LST and 0800 LST). The high nocturnal occurrence frequency of LLJ is mainly resulting from increased nocturnal ageostrophic wind. Research on the climatic impacts of large-scale conditions depicts that, the occurrence of LLJ in April mainly results from the northward shifting of western pacific subtropical high (WPSH), and the occurrence of LLJ in July results from the strengthening of detouring flow around Tibetan Plateau. Analysis of the climatic effects of LLJ on precipitation distribution in 3 rainy seasons over Southeast China indicates that the rainfall events with strong intensity correspond to strong LLJs. The LLJ affects the precipitation over Southeast China by transporting water vapor and triggering upward motion. Rainfall regions well corresponds to the regions of the moisture convergence and strong upward motion triggered by LLJ. Negative wind divergence anomalies at 850 hPa and positive wind divergence anomalies at 200 hPa over the Yangtze-Huaihe River Valley strengthen the upward motion over this region, which are conductive to produce more precipitation over the Yangtze-Huaihe River Valley.
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References
Bannon, P. R., 1979: On the dynamics of the east African jet, I: Simulation of mean conditions for July. J. Atmos. Sci., 36(11), 2139–2152.
Chen, H. M., T. J. Zhou, R. B. Neale, X. Q. Wu, and G. J. Zhang, 2010: Performance of the new NCAR CAM3.5 in East Asian summer monsoon simulations: Sensitivity to modifications of the convection scheme. J. Climate, 23, 3657–3675, doi:10.1175/2010JCLI3022.1.
Cook, K. H., 1999: Generation of the African easterly jet and its role in determining West African precipitation. J. Climate, 12(5), 1165–1184.
Ding, Y. H., 1992: Effects of the Qinghai-Xizang (Tibetan) Plateau on the circulation features over the Plateau and its surrounding areas. Adv. Atmos. Sci., 9, 112–130.
Du, Y., Y. C. Zhang, and Z. Q. Xie, 2009: Impacts of the zonal position of the East Asian westerly jet core on precipitation distribution during meiyu of China. Acta Meteorol. Sin., 23(4), 506–516.
Ernesto, M., J. B. Antonio, N. Sumant, and R.B. Alfredo, 2008: Winter and summer structure of the Caribbean low-level Jet. J. Climate, 21, 1260–1267, doi:10.1175/2007JCLI1855.1.
Higgins, R. W., Y. Yao, E. S. Yarosh, J. E. Janowiak, and K. C. Mo, 1997: Influence of the great plains low-level Jet on summertime precipitation and moisture transport over the Central United States. J. Climate, 10, 481–507.
Jiang, J. Y., J. X. Jiang, Y. L. Bu, and N. Q. Liu, 2008: Heavy rainfall associated with a monsoon depression in south China: structure analysis. Acta Meteorol. Sin., 22(1), 52–65.
Kalnay, E., and Coauthors, 1996: The NCEP/NCAR 40-Year reanalysis project. Bull. Amer. Meteor. Soc., 77, 437–471.
Kuang, X. Y., and Y. C. Zhang, 2006: Impact of the position abnormalities of East Asian subtropical westerly jet on summer precipitation in middle-lower reaches of Yangtze River, Plateau Meteorology. 25(3), 382–389. (in Chinese with English abstract)
Li, C., and M. Yanai, 1996: The onset and interannual variability of the Asian summer monsoon in relation to land-sea thermal contrast. J. Climate, 9, 358–375.
Li, J., R. C. Yu, and T. J. Zhou, 2008: Seasonal variation of the diurnal cycle of rainfall in the southern contiguous China. J. Climate, 21, 6036–6043, doi:10.1175/2008JCLI2188.1.
Limaitre, Y., and P. Brovelli, 1990: Role of a low level jet in triggering and organizing moist convection in a baroclinic atmosphere. A case study: 18 May 1984. J. Atmos. Sci., 47(1), 82–100.
Parrish, D. F., and J. C. Derber, 1992: The National Meteorological Center’s spectral statistical-interpolation analysis system. Mon. Wea. Rev., 120, 1747–1763.
Stensrud, D. J., 1996: Importance of low-level jets to climate: A review. J. Climate, 9, 1698–1711.
Sun, S. Q., and G. H. Zhai, 1980: On the the instability of the low level jet and its trigger function for the occurrence of heavy rain-storms. Scientia Atmospherica Sinica, 4(4), 327–337. (in Chinese with English abstract)
____, and D. O. Lorenzo, 1985: Influence of Tibetan plateau on low level jet in East Asia. Sci. Sinica (Series B), 28(1), 68–81.
____, 1986: The relationship between large-scale low-level jet over east asia and monsoon as well as cross-equatorial currents in summer. Acta Meteorol. Sin., 1(1), 43–50.
Tao, Z. Y., 1989: Analysis of Indian monsoon and associated low-level circulation in 1980 and 1981. Adv. Atmos. Sci., 6(1), 113–119.
Wang, C. Z., 2007: Variability of the Caribbean low-level jet and its relations to climate. Climate Dyn., 29, 411–422, doi: 10.1007/s00382-007-0243-z.
Xia, R. D., S. X. Zhao, and J. H. Sun, 2006: A study of circumstances of meso β scale systems of strong heavy rainfall in warm sector ahead of fronts in South China. Chinese J. Atmos. Sci., 30(5), 988–1008. (in Chinese with English abstract)
Ye, T. Z., and Y. X. Gao, 1979: The meteorology of the Qinghai-Xizang (Tibetan) Plateau. Science Press, 278 pp.
Yin, S. X., and X. Z. Tan, 1989: Branches of summer Asian low-level jet stream and its influence on the rain belt in China. Adv. Atmos. Sci., 6(3), 377–389.
Yu, R. C., Y. P. Xu, T. J. Zhou, and J. Li, 2007: Relation between rainfall duration and diurnal variation in the warm season precipitation over central eastern China. Geophys. Res. Lett., 34, L13703, doi:10.1029/2007GL030315.
Zhao, P., and X. J. Zhou, 2001: Formation of low-level meso-scale southwest jet during seasonal rainfall. Prog. Nat. sci., 11(4), 272–279.
Zhou, T. J., and Z. Li, 2002: Simulation of the east Asian summer monsoon by using a variable resolution atmospheric GCM. Climate Dyn., 19, 167–180, doi:10.1007/s00382-001-0214-8.
____, and R. C. Yu, 2005: Atmospheric water vapor transport associated with typical anomalous summer rainfall patterns in China. J. Geophys. Res., 110, D08104, doi:10.1029/2004JD005413.
____, _____, H. M. Chen, A. G. Dai, and Y. Pan, 2008: Summer precipitation frequency, intensity, and diurnal cycle over China: A comparison of satellite data with rain gauge observations. J. Climate, 21, 3997–4010, doi:10.1175/2008JCLI2028.1.
____, D. Y. Gong, J. Li, and B. Li, 2009: Detecting and understanding the multi-decadal variability of the East Asian Summer Monsoon-Recent progress and state of affairs. Meteor. Z., 18, 455–467, doi:10.1127/0941-2948/2009/0396.
Zhu, Q. G., J. R. Lin, and S. W. Shou, 1981: Principles and methods of synoptic meteorology. China Meteorological Press, 267 pp.
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Wang, D., Zhang, Y. & Huang, A. Climatic features of the south-westerly low-level jet over southeast china and its association with precipitation over east China. Asia-Pacific J Atmos Sci 49, 259–270 (2013). https://doi.org/10.1007/s13143-013-0025-y
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DOI: https://doi.org/10.1007/s13143-013-0025-y