The application of the orthogonal conditional nonlinear optimal perturbations method to typhoon track ensemble forecasts
- 18 Downloads
Abstract
The orthogonal conditional nonlinear optimal perturbations (CNOPs) method, orthogonal singular vectors (SVs) method and CNOP+SVs method, which is similar to the orthogonal SVs method but replaces the leading SV (LSV) with the first CNOP, are adopted in both the Lorenz-96 model and Pennsylvania State University/National Center for Atmospheric Research (PSU/NCAR) Fifth-Generation Mesoscale Model (MM5) for ensemble forecasts. Using the MM5, typhoon track ensemble forecasting experiments are conducted for strong Typhoon Matsa in 2005. The results of the Lorenz-96 model show that the CNOP+SVs method has a higher ensemble forecast skill than the orthogonal SVs method, but ensemble forecasts using the orthogonal CNOPs method have the highest forecast skill. The results from the MM5 show that orthogonal CNOPs have a wider horizontal distribution and better describe the forecast uncertainties compared with SVs. When generating the ensemble mean forecast, equally averaging the ensemble members in addition to the anomalously perturbed forecast members may contribute to a higher forecast skill than equally averaging all of the ensemble members. Furthermore, for given initial perturbation amplitudes, the CNOP+SVs method may not have an ensemble forecast skill greater than that of the orthogonal SVs method, but the orthogonal CNOPs method is likely to have the highest forecast skill. Compared with SVs, orthogonal CNOPs fully consider the influence of nonlinear physical processes on the forecast results; therefore, considering the influence of nonlinearity may be important when generating fast-growing initial ensemble perturbations. All of the results show that the orthogonal CNOP method may be a potential new approach for ensemble forecasting.
Keywords
Ensemble forecasts Initial perturbation Conditional nonlinear optimal perturbation Singular vector Typhoon trackNotes
Acknowledgements
The FNL data used in this study can be obtained from http://rda.ucar.edu/datasets/ds083.2/. The historical tropical cyclone data are available at http://tcdata.typhoon.org.cn/en/zjljsjj_zlhq.html. This work was sponsored by the National Natural Science Foundation of China (Grant Nos. 41525017 & 41475100), the National Programme on Global Change and Air-Sea Interaction (Grant No. GASI-IPOVAI-06), and the GRAPES Development Program of China Meteorological Administration (Grant No. GRAPES-FZZX-2018).
References
- Anderson J L. 1997. The impact of dynamical constraints on the selection of initial conditions for ensemble predictions: Low–order perfect model results. Mon Weather Rev, 125: 2969–2983CrossRefGoogle Scholar
- Barkmeijer J, Buizza R, Palmer T N, Puri K, Mahfouf J F. 2001. Tropical singular vectors computed with linearized diabatic physics. Q J R Meteorol Soc, 127: 685–708CrossRefGoogle Scholar
- Basnarkov L, Kocarev L. 2012. Forecast improvement in Lorenz 96 system. Nonlin Processes Geophys, 19: 569–575CrossRefGoogle Scholar
- Buizza R, Gelaro R, Molteni F, Palmer T N. 1997. The impact of increased resolution on predictability studies with singular vectors. Q J R Meteorol Soc, 123: 1007–1033CrossRefGoogle Scholar
- Cheung K K W. 2001. Ensemble forecasting of tropical cyclone motion: Comparisonbetween regional bred modes and random perturbations. Meteorol Atmos Phys, 78: 23–34CrossRefGoogle Scholar
- Chou K H, Wu C C, Lin P H, Aberson S D, Weissmann M, Harnisch F, Nakazawa T. 2011. The impact of dropwindsonde observations on typhoon track forecasts in DOTSTAR and T–PARC. Mon Weather Rev, 139: 1728–1743CrossRefGoogle Scholar
- Descamps L, Talagrand O. 2007. On some aspects of the definition of initial conditions for ensemble prediction. Mon Weather Rev, 135: 3260–3272CrossRefGoogle Scholar
- Ding R Q, Li J P, Li B S. 2017. Determining the spectrum of the nonlinear local Lyapunov exponents in a multidimensional chaotic system. Adv Atmos Sci, 34: 1027–1034CrossRefGoogle Scholar
- Duan M K, Wang P X. 2006. A new weighted method on ensemble mean forecasting (in Chinese). J Appl Meteorol, 17: 488–493Google Scholar
- Duan W S, Huo Z H. 2016. An approach to generating mutually independent initial perturbations for ensemble forecasts: Orthogonal conditional nonlinear optimal perturbations. J Atmos Sci, 73: 997–1014CrossRefGoogle Scholar
- Duan W S, Mu M, Wang B. 2004. Conditional nonlinear optimal perturbations as the optimal precursors for El Nino–Southern Oscillation events. J Geophys Res, 109: D23105CrossRefGoogle Scholar
- Duan W S, Mu M. 2009. Conditional nonlinear optimal perturbation: Applications to stability, sensitivity, and predictability. Sci China Ser DEarth Sci, 52: 883–906CrossRefGoogle Scholar
- Dudhia J. 1993. A nonhydrostatic version of the Penn State–NCAR mesoscale model: Validation tests and simulation of an Atlantic cyclone and cold front. Mon Weather Rev, 121: 1493–1513CrossRefGoogle Scholar
- Ehrendorfer M, Tribbia J J. 1997. Optimal prediction of forecast error covariances through singular vectors. J Atmos Sci, 54: 286–313CrossRefGoogle Scholar
- Elsberry R L, Hughes J R, Boothe M A. 2008. Weighted position and motion vector consensus of tropical cyclone track prediction in the western north pacific. Mon Weather Rev, 136: 2478–2487CrossRefGoogle Scholar
- Epstein E S. 1969. Stochastic dynamic predictions. Tellus, 21: 739–759CrossRefGoogle Scholar
- Evensen G. 1994. Sequential data assimilation with a nonlinear quasigeostrophic model using Monte Carlo methods to forecast error statistics. J Geophys Res, 99: 10143–10162CrossRefGoogle Scholar
- Feng J, Ding R Q, Liu D Q, Li J P. 2014. The application of nonlinear local Lyapunov vectors to ensemble predictions in lorenz systems. J Atmos Sci, 71: 3554–3567CrossRefGoogle Scholar
- Gelaro R, Rosmond T, Daley R. 2002. Singular vector calculations with an analysis error variance metric. Mon Weather Rev, 130: 1166–1186CrossRefGoogle Scholar
- Gilmour I, Smith L A. 1997. Enlightenment in Shadows. In: Kadtke J B, Bulsara A, eds. Applied Nonlinear Dynamics and Stochastic Systems near the Millennium. American Institute of Physics. 335–340Google Scholar
- Hamill T M, Snyder C, Whitaker J S. 2003. Ensemble forecasts and the properties of flow–dependent analysis–error covariance singular vectors. Mon Weather Rev, 131: 1741–1758CrossRefGoogle Scholar
- Hao S F, Cui X P, Pan J S. 2007. Ensemble prediction experiments of tracks of tropical cyclones by using multiple cumulus parameterizations schemes (in Chinese). J Trop Meteorol, 23: 569–574Google Scholar
- Jiang Z N, Mu M. 2009. A comparison study of the methods of conditional nonlinear optimal perturbations and singular vectors in ensemble prediction. Adv Atmos Sci, 26: 465–470CrossRefGoogle Scholar
- Jiang Z N, Wang H L, Zhou F F, Mu M. 2009. Applications of conditional nonlinear optimal perturbations to ensemble prediction and adaptive observation. Springer Verlag Berlin Heidelberg. 231–252Google Scholar
- Leith C E. 1974. Theoretical skill of monte carlo forecasts. Mon Weather Rev, 102: 409–418CrossRefGoogle Scholar
- Leutbecher M, Palmer T N. 2008. Ensemble forecasting. J Comput Phys, 227: 3515–3539CrossRefGoogle Scholar
- Li S, Rong X Y, Liu Y, Liu Z Y, Fraedrich K. 2013. Dynamic analogue initialization for ensemble forecasting. Adv Atmos Sci, 30: 1406–1420CrossRefGoogle Scholar
- Li Z J, Navon I M, Hussaini M Y. 2005. Analysis of the singular vectors of the full–physics Florida State University Global Spectral Model. Tellus Ser A–Dyn Meteorol Oceanol, 57: 560–574CrossRefGoogle Scholar
- Lorenz E N. 1965. A study of the predictability of a 28–variable model. Tellus, 17: 321–333CrossRefGoogle Scholar
- Lorenz E N. 1996. Predictability: A problem partly solved. In: Proc. Workshop on Predictability, Vol. 1. Reading, United Kingdom, ECMWF. 1–18Google Scholar
- Molteni F, Buizza R, Palmer T N, Petroliagis T. 1996. The ECMWF ensemble prediction system: Methodology and validation. Q J R Meteorol Soc, 122: 73–119CrossRefGoogle Scholar
- Mu M, Zhou F F, Wang H L. 2009. A method for identifying the sensitive areas in targeted observations for tropical cyclone prediction: Conditional nonlinear optimal perturbation. Mon Weather Rev, 137: 1623–1639CrossRefGoogle Scholar
- Mu M, Zhou F F, Qin X H, Chen B Y. 2014. The application of conditional nonlinear optimal perturbation to targeted observations for tropical cyclone prediction. In: Frontiers in Differential Geometry, Partial Differential Equations and Mathematical Physics. 291–325Google Scholar
- Mu M, Duan W S, Wang B. 2003. Conditional nonlinear optimal perturbation and its applications. Nonlin Processes Geophys, 10: 493–501CrossRefGoogle Scholar
- Mu M, Jiang Z N. 2008. A new approach to the generation of initial perturbations for ensemble prediction: Conditional nonlinear optimal perturbation. Chin Sci Bull, 53: 2062–2068Google Scholar
- Mu M, Zhang Z Y. 2006. Conditional nonlinear optimal perturbations of a two–dimensional quasigeostrophic model. J Atmos Sci, 63: 1587–1604CrossRefGoogle Scholar
- Mureau R, Molteni F, Palmer T N. 1993. Ensemble prediction using dynamically conditioned perturbations. Q J R Meteorol Soc, 119: 299–323CrossRefGoogle Scholar
- Palmer T N, Gelaro R, Barkmeijer J, Buizza R. 1998. Singular vectors, metrics, and adaptive observations. J Atmos Sci, 55: 633–653CrossRefGoogle Scholar
- Qin X H, Duan W S, Mu M. 2013. Conditions under which CNOP sensitivity is valid for tropical cyclone adaptive observations. Q J R Meteorol Soc, 139: 1544–1554CrossRefGoogle Scholar
- Revelli J A, Rodríguez M A, Wio H S. 2010. The use of rank histograms and MVL diagrams to characterize ensemble evolution in weather forecasting. Adv Atmos Sci, 27: 1425–1437CrossRefGoogle Scholar
- Reynolds C A, Peng M S, Chen J H. 2009. Recurving tropical cyclones: Singular vector sensitivity and downstream impacts. Mon Weather Rev, 137: 1320–1337CrossRefGoogle Scholar
- Roulston M S, Smith L A. 2003. Combining dynamical and statistical ensembles. Tellus A, 55: 16–30CrossRefGoogle Scholar
- Toth Z, Kalnay E. 1993. Ensemble forecasting at NMC: The generation of perturbations. Bull Amer Meteorol Soc, 74: 2317–2330CrossRefGoogle Scholar
- Toth Z, Zhu Y J, Marchok T. 2001. The use of ensembles to identify forecasts with small and large uncertainty. Weather Forecast, 16: 463–477CrossRefGoogle Scholar
- Wang C X, Liang X D. 2007. Ensemble prediction experiments of tropical cyclone track (in Chinese). J Appl Meteorol, 18: 586–593Google Scholar
- Wang H L, Mu M, Huang X Y. 2011. Application of conditional non–linear optimal perturbations to tropical cyclone adaptive observation using the weather research forecasting (WRF) model. Tellus A–Dynamic Meteor Oceanography, 63: 939–957CrossRefGoogle Scholar
- Ying M, Zhang W, Yu H, Lu X, Feng J, Fan Y, Zhu Y, Chen D. 2014. An overview of the China meteorological administration tropical cyclone database. J Atmos Ocean Technol, 31: 287–301CrossRefGoogle Scholar
- Yu H Z, Wang H L, Meng Z Y, Mu M, Huang X Y, Zhang X. 2017. A WRF–based tool for forecast sensitivity to the initial perturbation: The conditional nonlinear optimal perturbations versus the first singular vector method and comparison to MM5. J Atmos Ocean Technol, 34: 187–206CrossRefGoogle Scholar
- Yu J H, Tang J X, Dai Y H, Yu B Y. 2012. Analyses in Errors and Their Causes of Chinese Typhoon Track Operational Forecasts (in Chinese). Meteorol Monthly, 38: 695–700Google Scholar
- Zhang Z, Krishnamurti T N. 1997. Ensemble forecasting of hurricane tracks. Bull Amer Meteorol Soc, 78: 2785–2795CrossRefGoogle Scholar
- Zhou F F, Mu M. 2011. The impact of verification area design on tropical cyclone targeted observations based on the CNOP method. Adv Atmos Sci, 28: 997–1010CrossRefGoogle Scholar
- Zou X, Vandenberghe F, Pondeca M, Kuo Y. 1997. Introduction to adjoint techniques and the MM5 adjoint modeling system. NCAR Technical Note, NCAR/TN–435–STR, 107Google Scholar