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Patrick Duran and John Molinari

possible that a vertical grid spacing even smaller than 250 m is necessary to resolve cloud-top radiative tendencies. Meanwhile below the tropopause, time-mean radiative warming was present between the 30- and 160-km radii within the cirrus canopy. The existence of radiative cooling overlying radiative warming in this region led to radiatively forced destabilization at and below the tropopause, as was depicted in Fig. 7d . Beneath the warming layer existed a region of forcing for stabilization, while

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Benjamin C. Trabing, Michael M. Bell, and Bonnie R. Brown

) . Cloud-free radiative cooling could also be a potential mechanism for explaining the intensity differences between the Fullrad and Nightonly simulations ( Gray and Jacobson 1977 ). In the Nightonly simulations the enhanced cloud-free environmental subsidence driven by longwave cooling in the outer environment could force stronger inflow into the TC; however, no substantial differences were present in the outer-core radiative cooling rates over 24-h means (not shown). Due to the short time scale of

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William A. Komaromi and James D. Doyle

hypothesis, referred to as active outflow , is that a source of upper-level forcing that acts to accelerate or otherwise enhance the TC outflow can ultimately drive changes in the strength or structure of the vortex below (e.g., Sadler 1976 ; Holland and Merrill 1984 ; Nong and Emanuel 2003 ). Here, we do not seek to determine whether outflow is more likely to be passive or active. Instead, we explore the hypothesis that active outflow may contribute to TC intensification under the right set of

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David R. Ryglicki, Daniel Hodyss, and Gregory Rainwater

change in the orientation of the rotational axis of a rotating body, of the vortex tilt ( Jones 1995 , 2000 ; Schecter et al. 2002 ; Reasor et al. 2004 ; Schecter 2015 ; Reasor and Montgomery 2015 ). These nutations produce features in satellite imagery identified as tilt-modulated convective asymmetries (TCA). TCAs are distinct cloud structures that are separate from the diurnal signal ( Kossin 2002 ), pulse with a periodicity of 4–8 h on the left-of-shear side of the TC core, and do not rotate

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Yi Dai, Sharanya J. Majumdar, and David S. Nolan

1. Introduction The tropical cyclone (TC)–environmental flow interaction (TCEFI) plays an important role in TC structure and intensity change. Although some indices and methods exist to represent the TCEFI, they have mainly been developed in an axisymmetric framework. However, the azimuthally asymmetric interaction also needs to be considered, because the environmental flow is often highly asymmetric relative to the TC, thus creating an asymmetric forcing on the TC. Environmental features such

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Yi Dai, Sharanya J. Majumdar, and David S. Nolan

-mean tangential winds (RMW) of 90 km. It also has a Gaussian-like decay in the vertical with the maximum wind speed at z = 1500 m. The environmental shear profile and how it is introduced in the model are described below. b. Time-varying point-downscaling method The large-scale environmental shear is incorporated into the model using the point-downscaling method (PDS; Nolan 2011 ). Using PDS, the initial environmental flow is balanced by an artificial force that is added to the momentum equation so that

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