@article{4384a3092bb54a3fa287581c4538df07,
title = "Maximizing Simulated Tropical Cyclone Intensity With Action Minimization",
abstract = "Direct computer simulation of intense tropical cyclones (TCs) in weather models is limited by computational expense. Intense TCs are rare and have small-scale structures, making it difficult to produce large ensembles of storms at high resolution. Further, models often fail to capture the process of rapid intensification, which is a distinguishing feature of many intense TCs. Understanding rapid intensification is especially important in the context of global warming, which may increase the frequency of intense TCs. To better leverage computational resources for the study of rapid intensification, we introduce an action minimization algorithm applied to the Weather Research and Forecasting and WRFPLUS models. Action minimization nudges the model into forming more intense TCs than it otherwise would; it does so via the maximum likelihood path in a stochastic formulation of the model, thereby allowing targeted study of intensification mechanisms. We apply action minimization to simulations of Hurricanes Danny (2015) and Fred (2009) at 6-km resolution to demonstrate that the algorithm consistently intensifies TCs via physically plausible pathways. We show an approximately tenfold computational savings using action minimization to study the tail of the TC intensification distribution. Further, for Hurricanes Danny and Fred, action minimization produces perturbations that preferentially reduce low-level shear as compared to upper-level shear, at least above a threshold of approximately 4 m/s. We also demonstrate that asymmetric, time-dependent patterns of heating can cause significant TC intensification beyond symmetric, azimuthally averaged heating and find a regime of nonlinear response to asymmetric heating that has not been extensively studied in previous work.",
keywords = "WRF, action minimization, rapid intensification, tropical cyclone",
author = "Plotkin, {David A.} and Webber, {Robert J.} and O'Neill, {Morgan E.} and Jonathan Weare and Abbot, {Dorian S.}",
note = "Funding Information: We acknowledge support from the National Science Foundation under NSF award 1623064. This work was supported by the Department of Energy Computational Science Graduate Fellowship Program of the Office of Science and National Nuclear Security Administration in the Department of Energy under contract DE-FG02-97ER25308. R. W. and J. W. are supported by the Advanced Scientific Computing Research Program within the DOE Office of Science through award DE-SC0014205. R.W. was also supported by NSF RTG award 1547396. M. O. was supported by the T. C. Chamberlin Postdoctoral Fellowship at the University of Chicago. This work was completed with resources provided by the University of Chicago Research Computing Center. We would like to thank four anonymous reviewers, as well as Dr. David Nolan, for extensive suggestions for improving the manuscript. Code developed for action minimization applied to the WRF model is available at the website (https://knowledge.uchicago.edu/ handle/11417/1091). Funding Information: We acknowledge support from the National Science Foundation under NSF award 1623064. This work was supported by the Department of Energy Computational Science Graduate Fellowship Program of the Office of Science and National Nuclear Security Administration in the Department of Energy under contract DE-FG02-97ER25308. R. W. and J. W. are supported by the Advanced Scientific Computing Research Program within the DOE Office of Science through award DE-SC0014205. R.W. was also supported by NSF RTG award 1547396. M. O. was supported by the T. C. Chamberlin Postdoctoral Fellowship at the University of Chicago. This work was completed with resources provided by the University of Chicago Research Computing Center. We would like to thank four anonymous reviewers, as well as Dr. David Nolan, for extensive suggestions for improving the manuscript. Code developed for action minimization applied to the WRF model is available at the website (https://knowledge.uchicago.edu/handle/11417/1091). Publisher Copyright: {\textcopyright}2019. The Authors.",
year = "2019",
month = apr,
doi = "10.1029/2018MS001419",
language = "English (US)",
volume = "11",
pages = "863--891",
journal = "Journal of Advances in Modeling Earth Systems",
issn = "1942-2466",
publisher = "American Geophysical Union",
number = "4",
}