The evolution of hollow symmetric-PV tower during the landfall of Typhoon Mujigae (2015)

Abstract

The evolution of Typhoon Mujigae (2015) during the landfall period is determined using potential vorticity (PV) based on a high-resolution numerical simulation. Diabatic heating from deep moist convections in the eyewall produces a hollow PV tower extending from the lower troposphere to the middle levels. Since the potential temperature and wind fields could be highly asymmetric during landfall, the fields are divided into symmetric and asymmetric components. Thus, PV is split into three parts: symmetric PV, first-order asymmetric PV, and quadratic-order asymmetric PV. By calculating the azimuth mean, the first-order term disappears. The symmetric PV is at least one order of magnitude larger than the azimuthal mean quadratic-order term, nearly accounting for the mean cyclone. Furthermore, the symmetric PV tendency equation is derived in cylindrical coordinates. The budget terms include the symmetric heating term, flux divergence of symmetric PV advection due to symmetric flow, flux divergence of partial first-order PV advection due to asymmetric flow, and the conversion term between the symmetric PV and quadratic-order asymmetric term. The diagnostic results indicate that the symmetric heating term is responsible for the hollow PV tower generation and maintenance. The symmetric flux divergence largely offsets the symmetric heating contribution, resulting in a horizontal narrow ring and vertical extension structure. The conversion term contribution is comparable to the mean term contributions, while the contribution of the partial first-order PV asymmetric flux divergence is apparently smaller. The conversion term implicitly contains the combined effects of processes that result in asymmetric structures. This term tends to counteract the contribution of symmetric terms before landfall and favor horizontal PV mixing after landfall.

Keywords

landfall typhoon / potential vorticity / hollow PV tower / asymmetric features

References

[1] Chen Y, Yau M K (2003). Asymmetric structures in a simulated landfalling hurricane. J Atmos Sci, 60(18): 2294–2312

[2] Corbosiero K L, Molinari J, Black M L (2005). The structure and evolution of Hurricane Elena (1985). Part I: Symmetric intensification. Mon Weather Rev, 133(10): 2905–2921

[3] Duan Y H, Chen L S, Liang J Y, Wang Y, Wu L G, Cui X P, Ma L M, Li Q Q (2014). Research progress in the unusual variations of typhoons before and after landfalling. Acta Meteorol Sin, 72(5): 969–986 (in Chinese)

[4] Hendricks E A, Schubert W H, Chen Y H, Kuo H C, Peng M S (2014). Hurricane eyewall evolution in a forced shallow-water model. J Atmos Sci, 71(5): 1623–1643

[5] Jiao Y Y, Ran L K, Li N, Gao S T, Zhou G B (2017). High resolution numerical simulation of Typhoon Mujigae (2015) and analysis of vortex Rossby waves. Wuli Xuebao, 66(08): 381–400 (in Chinese)

[6] Kossin J P, Eastin M D (2001). Two distinct regimes in the kinematic and thermodynamic structure of the hurricane eye and eyewall. J Atmos Sci, 58(9): 1079–1090

[7] Kuo H C, Williams R T, Chen J H (1999). A possible mechanism for the eye rotation of Typhoon Herb. J Atmos Sci, 56(11): 1659–1673

[8] Kurihara Y, Bender M A, Ross R J (1993). An initialization scheme of hurricane models by vortex specification. Mon Weather Rev, 121(7): 2030–2045

[9] Kurihara Y, Bender M A, Tuleya R E, Ross R J (1995). Improvements in the GFDL hurricane prediction system. Mon Weather Rev, 123(9): 2791–2801

[10] Li Y, Qian C H, Chen L S (2009). A study on the eyewall expansion of Typhoon Sepat (2009) during its landfall process. Acta Meteorol Sin, 67(5): 799–810 (in Chinese)

[11] Liu S S, Liu S D (2011). Atmospheric Dynamics. 2nd ed. Beijing: Peking University Press, 92–93

[12] Meng Z Y, Xu X D, Chen L S (1998). Mechansism of the impact of the cyclone system induced by the Taiwan Island topography on tropical cyclone unusual motion. Chin J Atmos Sci, 22(2): 156–168 (in Chinese)

[13] Montgomery M T, Kallenbach R J (1997). A theory for vortex Rossby-waves and its application to spiral bands and intensity changes in hurricanes. Q J R Meteorol Soc, 123(538): 435–465

[14] Montgomery M T, Nicholls M E, Cram T A, Saunders A B (2006). A vortical hot tower route to tropical cyclogenesis. J Atmos Sci, 63(1): 355–386

[15] Montgomery M T, Smith R K (2014). Paradigms for tropical cyclone intensification. In: naval postgraduate school monterey ca dept of meteorology

[16] Nguyen M C, Reeder M J, Davidson N E, Smith R K, Montgomery M T (2011). Inner-core vacillation cycles during the intensification of Hurricane Katrina. Q J R Meteorol Soc, 137(657): 829–844

[17] Reasor P D, Montgomery M T, Marks F D Jr, Gamache J F (2000). Low-wavenumber structure and evolution of the hurricane inner core observed by airborne dual-Doppler radar. Mon Weather Rev, 128(6): 1653–1680

[18] Rozoff C M, Kossin J P, Schubert W H, Mulero P J (2009). Internal control of hurricane intensity variability: the dual nature of potential vorticity mixing. J Atmos Sci, 66(1): 133–147

[19] Schubert W H, Montgomery M T, Taft R K, Guinn T A, Fulton S R, Kossin J P, Edwards J P (1999). Polygonal eyewalls, asymmetric eye contraction, and potential vorticity mixing in hurricanes. J Atmos Sci, 56(9): 1197–1223

[20] Shapiro L J, Willoughby H E (1982). The response of balanced hurricanes to local sources of heat and momentum. J Atmos Sci, 39(2): 378–394

[21] Su H, Qian C, Gu H, Wang Q (2016). The impact of tropical cyclones on China in 2015. Trop Cyclone Res Rev, 5(1–2): 1–11

[22] Wang Y, Holland G J (1996). The beta drift of baroclinic vortices. Part II: Diabatic vortices. J Atmos Sci, 53(24): 3737–3756

[23] Wang Y (2002). Vortex Rossby waves in a numerically simulated tropical cyclone. Part I: Overall structure, potential vorticity, and kinetic energy budgets. J Atmos Sci, 59(7): 1213–1238

[24] Wang Y, Wu C C (2004). Current understanding of tropical cyclone structure and intensity changes—a review. Meteorol Atmos Phys, 87(4): 257–278

[25] Wei C S, Zhao K, Yu H, Wang M J (2011). Mesoscale structure of landfall Typhoon Khanun (0515) by single doppler Radar. Chin J Atmos Sci, 35(1): 68–80 (in Chinese)

[26] Williams G J Jr (2017). The generation and maintenance of hollow PV towers in a forced primitive equation model. In: Multidisciplinary Digital Publishing Institute Proceedings. 2017, 1(5): 156

[27] Wu C C, Cheng H J, Wang Y, Chou K H (2009). A numerical investigation of the eyewall evolution in a landfalling typhoon. Mon Weather Rev, 137(1): 21–40

[28] Yu J H, Tan Z M (2007). Island-like topographic effects on the propagation of vortex rossby waves. Journal of Nanjing University, 43(06):597–605 (in Chinese)

[29] Zhang D L, Liu Y, Yau M K (1999). Surface winds at landfall of Hurricane Andrew (1992)—A reply. Mon Weather Rev, 127(7): 1711–1721

[30] Zhang S F, Yu H, Xiang C Y (2015). Error analysis on official Typhoon intensity forecasts of CMO from 2001 to 2012. Meteorol Monogr, 41(10): 1278–1285 (in Chinese)

RIGHTS & PERMISSIONS

Higher Education Press and Springer-Verlag GmbH Germany, part of Springer Nature