On the characteristics of propagation of intraseasonal oscillations and their observed association with tropical synoptic waves in the Asian-western Pacific region in boreal summer

HE Jie-lin; WAN Qi-lin; GUAN Zhao-yong; LIN Ai-lan; WANG Li-juan

Abstract:

Using the daily average outgoing longwave radiation and NCEP/NCAR reanalysis data in boreal summer (Mays to Octobers) from 1979 to 2007, the propagating characteristics of convection intraseasonal oscillations (ISOs) in the Asian-western Pacific (AWP) region and the relationship between tropical synoptic waves and ISOs are examined by means of finite-domain wavenumber-frequency energy spectrum analysis and lagged linear regression technique. The results are shown as follows. (1) The AWP ISOs propagate both eastward and westward, showing seasonality and regionality. The ISOs propagate eastward with a period of 30 to 60 days over equatorial regions in the whole AWP region, while the westward propagation occurs over 10 to 20? N western Pacific or in the late summers (August, September and October) with periods of 20 to 40 days. The ISOs eastward propagation mainly occurs in primary summers while the westward propagation enhances in late summers. (2) Deep ISO convections associate with westerly and cyclonic circulation anomalies that first form in the Indian Ocean, propagate eastward to the dateline in the Pacific and then turn northwestward. The ISOs convections show northwestward propagating characteristics in the western North Pacific. (3) The ISOs link with the tropical synoptic waves closely. Both convection signals, though with different spatio-temporal scale, enhance simutaneously in the northwestern Pacific, and the ISOs facilitate the forming of a cluster of tropical cyclones (TCs), while a cluster of TCs convection becomes one portion of the northwestward ISOs.

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HE Jie-lin, WAN Qi-lin, GUAN Zhao-yong, et al. On the characteristics of propagation of intraseasonal oscillations and their observed association with tropical synoptic waves in the Asian-western Pacific region in boreal summer [J]. Journal of Tropical Meteorology, 2011, 17(3): 248-256.

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On the characteristics of propagation of intraseasonal oscillations and their observed association with tropical synoptic waves in the Asian-western Pacific region in boreal summer

Guangzhou Institute of Tropical and Marine Meteorology, CMA

Abstract: Using the daily average outgoing longwave radiation and NCEP/NCAR reanalysis data in boreal summer (Mays to Octobers) from 1979 to 2007, the propagating characteristics of convection intraseasonal oscillations (ISOs) in the Asian-western Pacific (AWP) region and the relationship between tropical synoptic waves and ISOs are examined by means of finite-domain wavenumber-frequency energy spectrum analysis and lagged linear regression technique. The results are shown as follows. (1) The AWP ISOs propagate both eastward and westward, showing seasonality and regionality. The ISOs propagate eastward with a period of 30 to 60 days over equatorial regions in the whole AWP region, while the westward propagation occurs over 10 to 20? N western Pacific or in the late summers (August, September and October) with periods of 20 to 40 days. The ISOs eastward propagation mainly occurs in primary summers while the westward propagation enhances in late summers. (2) Deep ISO convections associate with westerly and cyclonic circulation anomalies that first form in the Indian Ocean, propagate eastward to the dateline in the Pacific and then turn northwestward. The ISOs convections show northwestward propagating characteristics in the western North Pacific. (3) The ISOs link with the tropical synoptic waves closely. Both convection signals, though with different spatio-temporal scale, enhance simutaneously in the northwestern Pacific, and the ISOs facilitate the forming of a cluster of tropical cyclones (TCs), while a cluster of TCs convection becomes one portion of the northwestward ISOs.

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[1]	MADDEN R JULIAN P R. Detection of a 40-50 day oscillation in the zonal wind in the tropical Pacific [J]. J. Atmos. Sci., 1971, 28(5): 702-708.
[2]	MADDEN R A, JULIAN P R. Description of global-scale circulation cells in the tropics with a 40-50 day period [J]. J. Atmos. Sci., 1972, 29(6): 1109-1123.
[3]	NAKAZAWA T. Mean features of 30�C60 day variations as inferred from 8-year OLR data [J]. J. Meteor. Soc. Japan, 1986, 64(5): 777-786.
[4]	MADDEN R A, JULIAN P R. Observations of the 40-50-day tropical oscillation �Ca review [J]. Mon. Wea. Rev., 1994, 122(5): 814-837.
[5]	ZHU B Z, WANG B. The 30-60-day convection seesaw between the tropical Indian and western Pacific oceans [J]. J. Atmos. Sci., 1993, 50(2): 184-199.
[6]	KEMBALL-COOK S, WANG B. Equatorial waves and air�Csea interaction in the boreal summer intraseasonal oscillation [J]. J. Climate, 2001, 14(13): 2923-2942.
[7]	LI Chong-yin. Some fundamental problems of intraseasonal oscillation in the tropical atmosphere [J]. J. Trop. Meteor., 1995, 11(3): 276-288.
[8]	LI Li-ping, WANG Pan-xing, GUAN Zhao-yong. Review of the research on the atmospheric intraseasonal oscillation [J]. Nanjing Inst. Meteor., 2002, 25(4): 565-572.
[9]	HSU H H, WENG C H. Northwestward propagation of the intraseasonal oscillation in the western North Pacific during the boreal summer: structure and mechanism [J]. J. Climate, 2001, 14(18): 3834-3849.
[10]	TENG H, WANG B. Interannual variations of the boreal summer intraseasonal oscillation in the Asian-Pacific region [J]. J. Climate, 2003, 16(22): 3572-3584.
[11]	DONG Min, ZHANG Xing-jiang, HE Jin-hai. A diagnostic study on the temporal and spatial characteristics of the tropical intraseasonal oscillation [J]. Acta. Meteor. Sinica, 2004, 62 (6): 821-830.
[12]	LIN Ai-lan, LIANG Jian-yin, LI Chun-hui. Spectral variation characteristics of South China Sea summer monsoon convetion intraseasonal oscillation [J]. J. Trop. Meteor., 2005, 21 (5): 542-548.
[13]	MASUNAGA H. Seasonality and regionality of the Madden�CJulian oscillation, Kelvin wave, and equatorial Rossby wave [J]. J. Atmos. Sci., 2007, 64(12): 4400-4416.
[14]	LIN Ai-lan, LIANG Jian-yin, GU De-jun. Review of impacts of tropical atmospheric intraseasonal oscillation on East Asia monsoon and multiple time scales variation of tropical atmospheric intraseasonal oscillation [J]. J. Trop. Meteor., 2008, 24(1): 11-19.
[15]	LIN A, LI T. Energy Spectrum characteristics of boreal summer intraseasonal oscillations: climatology and variations during the ENSO developing and decaying phases [J]. J. Climate, 2008, 21(23): 6304-6320.
[16]	LIEBMANN B, HEDON H H. Synoptic-scale disturbances near the equator [J]. J. Atmos. Sci., 1990, 47(12): 1463-1479.
[17]	WHEELER M, KILADIS G N. Convectively coupled equatorial waves: Analysis of clouds and temperature in the wavenumber-frequency domain [J]. J. Atmos. Sci., 1999, 56(3): 374-399.
[18]	WHEELER M, KILADIS G N. WEBSTER P J. Large-scale dynamical fields associated with convectively coupled equatorial waves [J]. J. Atmos. Sci., 2000, 57(5): 613-640.
[19]	TAKAYABU Y N, NITTA T. 3-5 day-period disturbances coupled with convection over the tropical Pacific Ocean [J]. J. Meteor. Soc. Japan, 1993, 71(2): 221-245.
[20]	DUNKRRTON T J, BALDWIN M P. Observation of 3�C6-day meridional wind oscillations over the tropical Pacific, 1973�C1992: Horizontal structure and propagation [J]. J. Atmos. Sci., 1995, 52(10): 1585-1601.
[21]	DICKON M, MOLINARI J. Mixed Rossby�CGravity waves and western Pacific tropical cyclogenesis.part I: synoptic evolution [J]. J. Atmos. Sci., 2002, 59(14): 2183-2195.
[22]	STRAUB K H, KILADIS G N. Interactions between the boreal summer intraseasonal oscillation and higher-frequency tropical wave activity [J]. Mon. Wea. Rev., 2003, 131(5): 945-960.
[23]	ZHAI Pan-mao, GUO Yan-jun, LI Xiao-yan. A diagnostics analysis of 1997/1998 ENSO event of intra-seasonal oscillation in the tropical atmosphere [J]. J. Trop. Meteor., 2001, 17 (1): 1-9.
[24]	WANG Yun, ZHANG Qing-yun, PENG Jing-bei. Relationship between the intraseasonal oscillation of East Asian monsoon circulation and the heavy snow over southern China in boreal winter of 2007/2008 [J]. Clim. Environ. Res., 2008, 13(4): 459-467.
[25]	LIEBANN B B, HENDON H H, GLICK J D. The relationship between tropical cyclones of the western Pacific and Indian oceans and the Madden-Julian oscillation [J]. J. Meteor. Soc. Japan, 1994, 72(3): 401-411.
[26]	HALL J A, MATTHEWS J, KAROLY D J. The modulation of tropical cyclone activity in the Australian region by the Madden-Julian Oscillation [J]. Mon. Wea. Rev., 2001, 129(12): 2970-2982.
[27]	ZHU Cong-wen, NAKAZAWA T, LI Jian-ping. Modulation of tropical depression/cyclone over the Indian-western Pacific oceans by Madden-Julian oscillation [J]. Acta Meteor. Sinica. 2004, 62(1): 42-50.
[28]	KALNAY E, COAUTHORS. The NCEP/NCAR 40-year reanalysis project [J]. Bull. Amer. Meteor. Soc., 1996, 77(3): 437-470.
[29]	HAYASHI Y. Space�Ctime spectral analysis and its applications to atmospheric waves [J]. J. Meteor. Soc. Japan, 1982, 60(1): 156-171.
[30]	MURAKAMI T. Large-scale aspects of deep convective activity over the GATE area [J]. Mon. Wea. Rev., 1979, 107(8): 994-1013.
[31]	WANG B, XIE X. Low-frequency equatorial waves in vertically sheared zonal flow. Part I: Stable waves [J]. J. Atmos. Sci., 1996, 53(3): 449-467.
[32]	WANG B, XIE X. A model for the boreal summer intraseasonal oscillation [J]. J. Atmos. Sci., 1997, 54(1): 72-86.
[33]	LI Cong-yin. South Asian monsoon troughs (ridges) and tropical cyclone activity in association with mobility CISK waves [J]. Sci. China (Ser. B), 1985, 15(7): 667-674.
[34]	LAU K M, PENG L. Origin of low-frequency (intraseasonal) oscillations in the tropical atmosphere. Part I: basic theory [J]. J. Atmos. Sci., 1987, 44(6): 950-972.
[35]	CHANG C P, LIM H. Kelvin wave-CISK: A possible mechanism for the 30�C50 day oscillations [J]. J. Atmos. Sci., 1988, 45(11): 1709-1720.

On the characteristics of propagation of intraseasonal oscillations and their observed association with tropical synoptic waves in the Asian-western Pacific region in boreal summer

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