Abstract
Vertical wind shear fundamentally influences changes in tropical cyclone (TC) intensity. The effects of vertical wind shear on tropical cyclogenesis and evolution in the western North Pacific basin are not well understood. We present a new statistical study of all named TCs in this region during the period 2000–2006 using a second-generation partial least squares (PLS) regression technique. The results show that the lower-layer (between 850 hPa and 10 m above the sea surface) wind shear is more important than the commonly analyzed deep-layer shear (between 200 and 850 hPa) for changes in TC intensity during the TC intensification period. This relationship is particularly strong for westerly low-level shear. Downdrafts induced by the lower-layer shear bring low θ e air into the boundary layer from above, significantly reducing values of θ e in the TC inflow layer and weakening the TC. Large values of deep-layer shear over the ocean to the east of the Philippine Islands inhibit TC formation, while large values of lower-layer shear over the central and western North Pacific inhibit TC intensification. The critical value of deep-layer shear for TC formation is approximately 10 m s−1, and the critical value of lower-layer shear for TC intensification is approximately ±1.5 m s−1.
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Black, M. L., J. F. Gamache, F. D. Jr. Marks, et al., 2002: Eastern Pacific hurricanes Jimena of 1991 and Olivia of 1994: The effect of vertical shear on structure and intensity. Mon. Wea. Rev., 130(9), 2291–2312.
Chan, J. C. L., Y. H. Duan, and L. K. Shay, 2001: Tropical cyclone intensity change from a simple oceanatmosphere coupled model. J. Atmos. Sci., 58(2), 154–172.
DeMaria, M., J. A. Knaff, and C. Sampson, 2007: Evaluation of long-term trends in tropical cyclone intensity forecasts. Meteor. Atmos. Phys., 97(1–4), 19–28.
Emanuel, K. A., 1999: Thermodynamic control of hurricane intensity. Nature, 401(6754), 665–669.
Frank, W. M., and E. A. Ritchie, 2001: Effects of vertical wind shear on the intensity and structure of numerically simulated hurricanes. Mon. Wea. Rev., 129(9), 2249–2269.
Gallina, G. M., and C. S. Velden, 2002: Environmental vertical wind shear and tropical cyclone intensity change utilizing enhanced satellite derived wind information. Twenty-fifth Conference on Hurricanes and Tropical Meteorology, San Diego, CA, 29 April–3 May, Amer. Meteor. Soc., 172–173.
Hanley, D., J. Molinari, and D. Keyser, 2001: A composite study of the interactions between tropical cyclones and upper-tropospheric troughs. Mon. Wea. Rev., 129(10), 2570–2584.
Lin Huijuan and Zhang Yaochun, 2004: Climatic features of the tropical cyclone influencing China and its relationship with the sea surface temperature in the Pacific Ocean. J. Trop. Meteor., 20(2), 218–224. (in Chinese)
Lowag, A., M. L. Black, and M. D. Eastin, 2008: Structural and intensity changes of hurricane Bret (1999). Part 1: Environmental influences. Mon. Wea. Rev., 136(11), 4320–4333.
Nguyen, S. V., R. K. Smith, and M. T. Montgomery, 2008: Tropical-cyclone intensification and predictability in three dimensions. Quart. J. Roy. Meteor. Soc., 134(632), 563–582.
Palmén, E., 1948: On the formation and structure of tropical hurricanes. Geophysica, 3, 26–38.
Reasor, P. D., M. T. Montgomery, and L. D. Grasso, 2004: A new look at the problem of tropical cyclones in vertical shear flow: Vortex resiliency. J. Atmos. Sci., 61(1), 3–22.
Reynolds, R. W., and D. C. Marsico, 1993: An improved real-time global sea surface temperature analysis. J. Climate, 6(1), 114–119.
Riemer, M., and M. T. Montgomery, 2010: Simple kinematic models for the environmental interaction of tropical cyclones in vertical wind shear. Atmos. Chem. Phys. Discuss., 10(11), 28057–28107.
—, —, and M. E. Nicholls, 2010: A new paradigm for intensity modification of tropical cyclones: Thermodynamic impact of vertical wind shear on the inflow layer. Atmos. Chem. Phys., 10(7), 3163–3188.
Ritchie, E. A., 2002: Environmental Effects. Reports of the Fifth WMO International Workshop on Tropical Cyclones IWTC-V, WMO Tech. Doc. WMO/TD1136.
Schecter, D. A., and M. T. Montgomery, 2003: On the symmetrization rate of an intense geophysical vortex. Dyn. Atmos. Oceans, 37(1), 55–88.
Shay, L. K., G. J. Goni, and P. G. Black, 2000: Effects of a warm oceanic feature on Hurricane Opal. Mon. Wea. Rev., 128(5), 1366–1383.
Shu Shoujuan, Wang Yuan, and Xiong Anyuan, 2007: Estimation and analysis of geographic and orographic influences on precipitation distribution in China. Chinese J. Geophys., 50(6), 1703–1712. (in Chinese)
Smoliak, B. V., J. M. Wallace, M. T. Stoelinga, et al., 2010: Application of partial least squares regression to the diagnosis of year-to-year variations in Pacific Northwest snowpack and Atlantic hurricanes. Geophys. Res. Lett., 37, L03801, doi: 10.1029/2009GL041478.
Song, J. J., Y. Wang, and L. G. Wu, 2010: Trend discrepancies among three best track data sets of western North Pacific tropical cyclones. J. Geophys. Res., 115, D12128, doi: 10.1029/2009JD013058.
Wold, H., 1966: Estimation of principal components and related models by iterative least squares. Multivariate Analysis, P. R. Krishnaiaah, Ed., Academic Press, New York, 391–420.
Wu, L. G., and S. A. Braun, 2004: Effects of environmentally induced asymmetries on hurricane intensity: A numerical study. J. Atmos. Sci., 61(24), 3065–3081.
Zehr, R. M., 1992: Tropical Cyclogenesis in the Western North Pacific. NOAA Tech. Rep. NESDIS61, 1–181.
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Supported by the National (Key) Basic Research and Development (973) Program of China (2009CB421502), China Meteorological Administration Special Public Welfare Research Fund (GYHY201006007), National Natural Science Foundation of China (40905020), State Key Laboratory of SevereWeather (2011LASW-B11), and Funds for the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions.
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Shu, S., Wang, Y. & Bai, L. Insight into the role of lower-layer vertical wind shear in tropical cyclone intensification over the western North Pacific. Acta Meteorol Sin 27, 356–363 (2013). https://doi.org/10.1007/s13351-013-0310-9
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DOI: https://doi.org/10.1007/s13351-013-0310-9