ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-11-4177-2011 Statistical dynamics of tropical wind in radiosonde data Koh T.-Y. 1 2 3 Djamil Y. S. 1 Teo C.-K. 3 School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore Earth Observatory of Singapore, Nanyang Technological University, Singapore Temasek Laboratories, Nanyang Technological University, Singapore 06 05 2011 11 9 4177 4189 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/11/4177/2011/acp-11-4177-2011.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/11/4177/2011/acp-11-4177-2011.pdf

Weibull distributions were fitted to wind speed data from radiosonde stations in the global tropics. A statistical theory of independent wind contributions was proposed to partially explain the shape parameter <i>k</i> obtained over Malay Peninsula and the wider Equatorial Monsoon Zone. This statistical dynamical underpinning provides some justification for using empirical Weibull fits to derive wind speed thresholds for monitoring data quality. The regionally adapted thresholds retain more useful data than conventional ones defined from taking the regional mean plus three standard deviations. The new approach is shown to eliminate reports of atypically strong wind over Malay Peninsula which may have escaped detection in quality control of global datasets as the latter has assumed a larger spread of wind speed. New scientific questions are raised in the pursuit of statistical dynamical understanding of meteorological variables in the tropics.

 References Arfken, G. B., Weber, H. J., and Harris, F.: Mathematical Methods for Physicists, 5th Ed., Academic Press, p 1112, 2000. Artstein, S., Ball, K. M., Barthe, F., and Naor, A.: Solution of Shannon's problem on the monotonicity of entropy, J. Am. Math. Soc., 17(4), 975–982, 2004. Chang, C. P., Liu, C. H., and Kuo, H. C.: Typhoon Vamei: An equatorial tropical cyclone formation, Geophys. Res. Lett., 30(3), 1150, http://dx.doi.org/10.1029/2002GL016365doi:10.1029/2002GL016365, 2003. Chang, C. P., Wang, Z., McBride, J., and Liu, C. H.: Annual cycle of Southeast Asia - Maritime continent rainfall and the asymmetric monsoon transition, J. Climate, 18, 287–301, 2005. Divakarla, M. G., Barnet, C. D., Goldberg, M. D., McMillin, L. M., Maddy, E., Wolf, W., Zhou, L., and Liu, X.: Validation of Atmospheric Infrared Sounder temperature and water vapor retrievals with matched radiosonde measurements and forecasts, J. Geophys. Res., 111, D09S15, http://dx.doi.org/10.1029/2005JD006116doi:10.1029/2005JD006116, 2006. Durre, I., Vose, R. S., and Wuertz, D. B.: Overview of the Integrated Global Radiosonde Archive, J. Climate, 19, 53–68, 2006. Feller, W.: An Introduction to Probability Theory and its Applications, 3rd Ed., Wiley, New York, 227–233, 1968. Frank, H. P. and Landberg, L.: Modelling the wind climate of Ireland, Bound.-Lay. Meteorol., 85, 359–378, 1997. Gandin, L. S.: Complex quality control of meteorological observations, Mon. Weather Rev., 116, 1137–1156, 1988. Hadi, T. W., Horinouchi, T., Tsuda, T., Hashiguchi, H., and Fukao, S.: Sea-breeze circulation over Jakarta, Indonesia: A climatology based on boundary layer radar observations, Mon. Weather Rev., 130, 2153–2166, 2002. Hendon, H. H.: Indonesian rainfall variability: Impacts of ENSO and local air-sea interaction, J. Climate, 16, 1795–1790, 2003. Ibarra, J. I.: A new approach for the determination of horizontal wind direction fluctuations, J. Appl. Meteorol. Clim., 34, 1942–1949, 1995. Joseph, B., Bhatt, B. C., Koh, T. Y., and Chen, S.: Sea breeze simulation over Malay Peninsula over an intermonsoon period, J. Geophys. Res., 113, D20122, http://dx.doi.org/10.1029/2008JD010319doi:10.1029/2008JD010319, 2008. Juneng, L. and Tangang, F. T.: Evolution of ENSO-related rainfall anomalies in Southeast Asia region and its relationship with atmosphere-ocean variations in Indo-Pacific sector, Clim. Dynam., 25, 337–350, 2005. Justus, C. G., Hargraves, W. R., Mikhail, A., and Graber, D.: Methods for estimating wind speed frequency distributions. J. Appl. Meteor., 17, 350–353, 1978. Katz, R. W.: Sir Gilbert Walker and a Connection between El Niño and Statistics, Stat. Sci., 17, 97–117, 2002. Koh, T. Y. and Ng, J. S.: Improved diagnostics for NWP verification in the tropics, J. Geophys. Res., 114, D12102, http://dx.doi.org/10.1029/2008JD011179doi:10.1029/2008JD011179, 2009. Koh, T. Y. and Teo, C. K.: Towards a mesoscale observation network in Southeast Asia, B. Amer. Meteorol. Soc., 90(4), 481–488, http://dx.doi.org/10.1175/2008BAMS2561.1doi:10.1175/2008BAMS2561.1, 2009. Labraga, J. C.: Extreme winds in the Pampa del Castillo plateau, Patagonia, Argentina, with reference to wind farm settlement, J. Appl. Meteorol., 33, 85–95, 1994. Lau, K. M. and Yang, S.: Climatology and interannual variability of the Southeast Asian summer monsoon, Adv. Atmos. Sci., 14, 141–162, 1997. Lun, I. Y. F. and Lam, J. C.: A study of Weibull parameters using long-term wind observations, Renewable Energy., 20, 145–153, 2000. Madden, R. A. and Julian, P. R.: Description of a 40–50~day oscillation in the zonal wind in the tropical Pacific, J. Atmos. Sci., 28, 702–708, 1971. Madden, R. A. and Julian, P. R.: Observations of the 40–50-day tropical oscillation – a review, Mon. Weather Rev., 122, 814–837, 1994. Manwell, J. F., McGowan, J. G., and Rogers, A. L.: Wind characteristics and resources. In: Wind Energy Explained, Theory, Design and Application, Wiley, New York, 21–80, 2002. Mori, Y.: Evaluation of several "single-pass" estimators of the mean and the standard deviation of wind direction, J. Clim. Appl. Meteorol., 25, 1387–1397, 1986. Neale, R. B. and Slingo, J. M.: The maritime continent and its role in the global climate: a GCM study, J. Climate, 16, 834–848, 2003. Okamoto, N., Yamanaka, M. D., Ogino S.-Y., Hashiguchi, H., Nishi, N., Sribimawati, T., and Numaguti, A.: Seasonal variations of tropospheric wind over Indonesia: comparison between collected operational rawinsonde data and NCEP reanalysis for 1992–1999, J. Meteorol. Soc. Japan, 81, 829–850, 2003. Ramage, C. S.: Role of a tropical maritime continent in the atmospheric circulation, Mon. Weather Rev., 96, 365–370, 1968. Ramage, C. S.: Monsoon Meteorology, Academic Press, 296~pp., 1971. Roney, J. A.: Statistical wind analysis for near-space applications, J. Atmos. Sol.-Terr. Phy., 69, 1485–1501, 2007. Rotunno, R. A.: On the linear theory of the land and sea breeze, J. Atmos. Sci., 41, 1999–2009, 1983. Sardeshmukh, P. D. and Sura, P.: Reconciling non-Gaussian climate statistics with linear dynamics, J. Climate, 22, 1193–1207, http://dx.doi.org/10.1175/2008JCLI2358.1doi:10.1175/2008JCLI2358.1, 2009. Stoffelen, A., Pailleux, J., Källén, E., Vaughan, J. M., Isaksen, L., Flamant, P., Wergen, W., Andersson, E., Schyberg, H., Culoma, A., Meynart, R., Endemann, M., and Ingmann, P.: The atmospheric dynamics mission for global wind measurement, B. Am. Meteorol. Soc., 86, 73–87, 2005. Takle, E. S. and Brown, J. M.: Note on the use of Weibull statistics to characterize wind-speed data, J. Appl. Meteorol., 17, 556–559, 1978. Wang, B.: The Asian Monsoon. Springer-Praxis, Heidelberg, Germany, p 844, 2006. Waliser, D. E.: Intraseasonal variability, in: The Asian Monsoon, Springer-Praxis, Heidelberg, Germany, 203–257, 2006. Webster, P. J. and Holton, J. R.: Wave propagation through a zonally varying basic flow: the influences of mid-latitude forcing in the equatorial regions, J. Atmos. Sci., 39, 722–733, 1982. Wheeler, M. and Kiladis, G. N.: Convectively coupled equatorial waves: analysis of clouds and temperature in the wavenumber-frequency domain, J. Atmos. Sci., 56, 374–399, 1999. Whittaker, E T. and Watson, G N.: A Course in Modern Analysis, 4th ed, Cambridge University Press, England, 680~pp., 1996. Widger Jr., W. K.: Estimations of wind speed frequency distributions using only the monthy average and fastest mile data, J. Appl. Meteorol., 16, 244–247, 1977. Wilks, D. S.: Statistical methods in the atmospheric sciences, Academic Press, London, 467~pp., 1995. Zhu, B. and Wang, B.: The 30–60~day convection see-saw between the tropical Indian and western Pacific Oceans, J. Atmos. Sci., 50, 184–199, 1993.