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A Study of Teleconnection between the South Asian and East Asian Monsoons: Comparison of Summer Monsoon Precipitation of Nepal and South Korea

Choi, Ki-Seon;Shrestha, Rijana;Kim, Baek-Jo;Lu, Riyu;Kim, Jeoung-Yun;Park, Ki-Jun;Jung, Ji-Hoon;Nam, Jae-Cheol

  • Received : 2014.08.21
  • Accepted : 2014.10.16
  • Published : 2014.10.31

Abstract

This study is carried out in order to bridge the gap to understand the relationships between South Asian and East Asian monsoon systems by comparing the summer (June-September) precipitation of Nepal and South Korea. Summer monsoon precipitation data from Nepal and South Korea during 30 years (1981-2010) are used in this research to investigate the association. NCEP/NCAR reanalysis data are also used to see the nature of large scale phenomena. Statistical applications are used to analyze these data. The analyzed results show that summer monsoon precipitation is higher over Nepal ($1513.98{\pm}159.29mm\;y^{-1}$) than that of South Korea ($907.80{\pm}204.71mm\;y^{-1}$) and the wettest period in both the countries is July. However, the coefficient of variation shows that amplitude of interannual variation of summer monsoon over South Korea (22.55%) is larger in comparison to that of Nepal (10.52%). Summer monsoon precipitation of Nepal is found to be significantly correlated to that of South Korea with a correlation coefficient of 0.52 (99% confidence level). Large-scale circulations are studied to further investigate the relationship between the two countries. wind and specific humidity at 850 hPa show a strong westerly from Arabian Sea to BOB and from BOB, wind moves towards Nepal in a northwestward direction during the positive rainfall years. In case of East Asia, strong northward displacement of wind can be observed from Pacific to South Korea and strong anticyclone over the northwestern Pacific Ocean. However, during the negative rainfall years, in the South Asian region we can find weak westerly from the Arabian Sea to BOB, wind is blowing in a southerly direction from Nepal and Bangladesh to BOB.

Keywords

Summer monsoon precipitation;South Asian and East Asian monsoon;Western North Pacific subtropical high;Tibetan high;Teleconnection

References

  1. Kalnay, E., Kanamitsu M., Kistler R., Collins W., Deaven D., Gandin L., Iredell M., Saha S., White G., Woollen J., 1996, The NCEP/NCAR 40-year reanalysis project. Bulletin of American Meteorological Society, 77, 437-471. https://doi.org/10.1175/1520-0477(1996)077<0437:TNYRP>2.0.CO;2
  2. Kim, B. J., Moon S. E., Riyu L., Kripalani R. H., 2002, Teleconnections: Summer monsoon over Korea and India. Advvances in Atmospheric Sciences, 19, 665-676. https://doi.org/10.1007/s00376-002-0006-z
  3. Kripalani, R. H., Kulkarni A., 2001, Monsoon rainfall variations and teleconnections over South and East Asia. International Journal of Climatology, 21, 603-616. https://doi.org/10.1002/joc.625
  4. Lau, K. M., Yang G. J., Shen S. H., 1988, Seasonal and intraseasonal climatology of summer monsoon rainfall over East Asia. Monthly Weather Review, 116 (1), 18-37. https://doi.org/10.1175/1520-0493(1988)116<0018:SAICOS>2.0.CO;2
  5. Li, C., Yanai M., 1996, The onset and interannual variability of the Asian summer monsoon in relation to land-sea thermal contrast. Journal of Climate, 9, 358-375. https://doi.org/10.1175/1520-0442(1996)009<0358:TOAIVO>2.0.CO;2
  6. Sigdel, M., Ikeda M.. 2012, Summer monsoon rainfall over Nepal related with large-scale atmospheric circulations. Journal of Earth Science and Climate Change, 3, 112 -121.
  7. Lu, R., 2001, Interannual variability of the summertime North Pacific subtropical high and its relation to atmospheric convection over the warm pool. Journal of Meteorological Society of Japan, 79, 771-783. https://doi.org/10.2151/jmsj.79.771
  8. Qian, W., Zhu Y., 2002, The comparison between summer monsoon components over East Asia and South Asia. Journal of Geosciences China, 4, 17-32.
  9. Shrestha, M. L., 2000, Interannual variation of summer monsoon rainfall over Nepal and its relation to Southern Oscillation Index. Meteorological and Atmospheric Physics, 75, 21-28. https://doi.org/10.1007/s007030070012
  10. Wang, B., Clemens S. C., Lui P., 2003, Contrasting the Indian and East Asian monsoons: implications on geologic timescales. Marine Geology, 201, 5-21. https://doi.org/10.1016/S0025-3227(03)00196-8
  11. Zhao, P., Zhang X., Li Y., Chen J., 2009, Remotely modulated tropical-North Pacific ocean-atmosphere interactions by the South Asian high. Atmospheric Research, 94, 45-60. https://doi.org/10.1016/j.atmosres.2009.01.018
  12. Ho, C. H., Lee J. Y., Ahn M. H., Lee S. H., 2003, A sudden change in summer rainfall characteristics in Korea during the late 1970s. International Journal of Climatology, 23, 117-128. https://doi.org/10.1002/joc.864
  13. Ichiyanagi, K., Manabu Y. D., Muraji Y., Vaidya B. K., 2007, Precipitation in Nepal between 1987 and 1996. International Journal of Climatology, 27, 1753-1762. https://doi.org/10.1002/joc.1492

Cited by

  1. Relationship between Indian and East Asian summer rainfall variations vol.34, pp.1, 2017, https://doi.org/10.1007/s00376-016-6216-6
  2. The impacts of the Indian summer rainfall on North China summer rainfall vol.53, pp.2, 2017, https://doi.org/10.1007/s13143-017-0013-8

Acknowledgement

Grant : Development and application of technology for weather forecast

Supported by : Korea Meteorological Administration