Interannual Variation of the Summer Synoptic-Scale Disturbance Activity in the Western Tropical Pacific

Tsing-Chang Chen Atmospheric Science Program, Department of Geological and Atmospheric Sciences, Iowa State University, Ames, Iowa

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Shu-Ping Weng Atmospheric Science Program, Department of Geological and Atmospheric Sciences, Iowa State University, Ames, Iowa

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Abstract

The authors computed the occurrence frequency of synoptic-scale disturbances over the western tropical Pacific with a simple synoptic scheme and the Goddard Earth Observing System data for 1980–94 supplemented by the 1979 National Meteorological Center (currently the National Centers for Environmental Prediction) data. The major occurrence of these disturbances exists along the monsoon trough with maximum occurrence frequency over Micronesia. The occurrence frequency distribution undergoes an interannual variation through the influence of large-scale circulation during boreal summer. As a part of the interannual variation of large-scale summer circulation in the Pacific basin, a major anomalous anticyclonic (cyclonic) circulation cell emerges in the western subtropical Pacific (north of 15°N), and a minor anomalous cyclonic (anticyclonic) circulation cell appears in the western tropical Pacific (south of 15°N) during warm (cold) summers. The tropical synoptic-scale disturbance activity is affected by these anomalous summer circulations in the following two ways: 1) the maximum occurrence frequency appears east (west) of 150°E (the east end of the climatological monsoon trough) during warm (cold) summers, and 2) tropical synoptic-scale disturbances are located primarily south of 15°N during warm summers, while their occurrences are enhanced north of 15°N during cold summers. Since the effort made here is a pilot study, the authors suggest some potential investigations of tropical synoptic-scale disturbances and interannual variations of large-scale summer circulation.

Corresponding author address: Tsing-Chang Chen, 3010 Agronomy Hall, Atmospheric Science Program, Dept. of Geological and Atmospheric Sciences, Iowa State University, Ames, IA 50011.

Email: tmchen@iastate.edu

Abstract

The authors computed the occurrence frequency of synoptic-scale disturbances over the western tropical Pacific with a simple synoptic scheme and the Goddard Earth Observing System data for 1980–94 supplemented by the 1979 National Meteorological Center (currently the National Centers for Environmental Prediction) data. The major occurrence of these disturbances exists along the monsoon trough with maximum occurrence frequency over Micronesia. The occurrence frequency distribution undergoes an interannual variation through the influence of large-scale circulation during boreal summer. As a part of the interannual variation of large-scale summer circulation in the Pacific basin, a major anomalous anticyclonic (cyclonic) circulation cell emerges in the western subtropical Pacific (north of 15°N), and a minor anomalous cyclonic (anticyclonic) circulation cell appears in the western tropical Pacific (south of 15°N) during warm (cold) summers. The tropical synoptic-scale disturbance activity is affected by these anomalous summer circulations in the following two ways: 1) the maximum occurrence frequency appears east (west) of 150°E (the east end of the climatological monsoon trough) during warm (cold) summers, and 2) tropical synoptic-scale disturbances are located primarily south of 15°N during warm summers, while their occurrences are enhanced north of 15°N during cold summers. Since the effort made here is a pilot study, the authors suggest some potential investigations of tropical synoptic-scale disturbances and interannual variations of large-scale summer circulation.

Corresponding author address: Tsing-Chang Chen, 3010 Agronomy Hall, Atmospheric Science Program, Dept. of Geological and Atmospheric Sciences, Iowa State University, Ames, IA 50011.

Email: tmchen@iastate.edu

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  • Allan, R., J. Lindesay, and D. Parker, 1996: El Niño Southern Oscillation and Climate Variability. CSIRO Publishing, 405 pp.

  • Bjerknes, J., 1969: Atmospheric teleconnections from the equatorial Pacific. Mon. Wea. Rev.,97, 163–172.

  • Chang, C.-P., 1970: Westward propagating cloud patterns in the tropical Pacific as seen from time-composite satellite photographs. J. Atmos. Sci.,27, 133–138.

  • ——, and C. R. Miller III, 1977: Comparison of easterly waves in the tropical Pacific during two contrasting periods of sea surface temperature anomalies. J. Atmos. Sci.,34, 615–628.

  • Chen, T.-C., and M.-C. Yen, 1994: Interannual variation of the Indian monsoon simulated by the NCAR Community Climate Model: Effect of the tropical Pacific SST. J. Climate,7, 1403–1415.

  • ——, and S.-P. Weng, 1996: Some effects of the intraseasonal oscillation on the equatorial waves over the western tropical Pacific–South China sea region during the northern summer. Mon. Wea. Rev.,124, 751–756.

  • Dunkerton, T. J., and M. P. Baldwin, 1995: Observation of 3–6-day meridonal wind oscillation over the tropical Pacific, 1973–1992:Horizontal structure and propagation. J. Atmos. Sci.,52, 1585–1601.

  • Krishnamurti, T. N., 1979: Tropical Meteorology. Compendium of Meteorology II, WMO-No. 364, World Meteorological Organization, 428 pp.

  • Lau, K.-H., and N.-C. Lau, 1990: Observed structure and propagation characteristics of tropical summertime synoptic scale disturbances. Mon. Wea. Rev.,118, 1888–1913.

  • Lau, K.-M., and L. Peng, 1992: Dynamics of atmospheric teleconnections during the northern summer. J. Climate,5, 140–158.

  • Liebmann, B., and H. H. Hendon, 1990: Synoptic-scale disturbances near the equator. J. Atmos. Sci.,47, 1463–1479.

  • Meehl, G. A., 1994: Influence of the land surface in the Asian summer monsoon: External conditions versus internal feedbacks. J. Climate,7, 1033–1049.

  • Murakami, M., 1979: Large-scale aspects of deep convective activity over the GATE area. Mon. Wea. Rev.,107, 994–1013.

  • Nitta, T., 1970: A study of generation and conversion of eddy available potential energy in the tropics. J. Meteor. Soc. Japan,48, 524–528.

  • ——, 1972: Energy budget of wave disturbances over the Marshall Islands during the years of 1956 and 1958. J. Meteor. Soc. Japan,50, 71–84.

  • ——, 1982: Tropical Meteorology (in Japanese), Tokyo Publication, 215 pp.

  • ——, 1987: Convective activities in the tropical western Pacific and their impact on the Northern Hemisphere circulation. J. Meteor. Soc. Japan,65, 373–390.

  • ——, Y. Nakagomi, Y. Suszuki, N. Hasegawa, and A. Kadokura, 1985: Global analysis of the lower tropospheric disturbances in the tropics during the northern summer of the FGGE year. Part I: Global features of the disturbances. J. Meteor. Soc. Japan,63, 1–19.

  • Philander, G. S., 1990: El Niño, La Niña, and the Southern Oscillation. Academic Press, 293 pp.

  • Reed, R. J., and E. E. Recker, 1971: Structure and properties of synoptic scale wave disturbances in the equatorial western Pacific. J. Atmos. Sci.,28, 1117–1133.

  • Reynolds, R. W., 1988: A real-time global sea surface temperature analysis. J. Climate,1, 75–86.

  • ——, and D. C. Marscio, 1993: An improved real-time global sea surface temperature analysis. J. Climate,6, 114–119.

  • Saha, K., F. Sanders, and J. Shukla, 1981: Westward propagating predecessors of monsoon depressions. Mon. Wea. Rev.,109, 330–343.

  • Salby, M. L., H. H. Hendon, K. Woodberry, and K. Tanaka, 1991: Analysis of global cloud imagery from multiple satellite. Bull. Amer. Meteor. Soc.,72, 467–480.

  • Schubert, S. D., J. Pfaendtner, and R. Rood, 1993: An assimilated data set for earth science applications. Bull. Amer. Meteor. Soc.,74, 2331–2342.

  • Shukla, J., 1987: Interannual variability of monsoons. Monsoons, J. Fein and P. L. Stephens, Eds., Wiley and Sons, 399–463.

  • Sinclair, M. S., 1994: An objective cyclone climatology for the Southern Hemisphere. Mon. Wea. Rev.,122, 2339–2256.

  • Tai, K.-S., and Y. Ogura, 1987: An observational study of easterly waves over the eastern Pacific in the northern summer using FGGE data. J. Atmos. Sci.,44, 339–361.

  • Wallace, J. M., 1971: Spectral studies of tropospheric wave disturbances in the tropical western Pacific. Rev. Geophys. Space Phys.,9, 557–612.

  • ——, and C. P. Chang, 1969: Spectral analysis of large-scale wave disturbance in the tropical lower troposphere. J. Atmos. Sci.,26, 1010–1025.

  • Whittaker, L. M., and L. H. Horn, 1983: Northern Hemisphere extratropical cyclone activity for our mid-season months. J. Climatol.,4, 297–310.

  • Zipser, E. J., 1970: The Line Island Experiment, its place in tropical meteorology and the rise of the fourth school of thought. Bull. Amer. Meteor. Soc.,51, 1136–1146.

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