Search Results

You are looking at 1 - 7 of 7 items for :

  • Tropical Cyclone Intensity Experiment (TCI) x
  • Journal of the Atmospheric Sciences x
  • Refine by Access: All Content x
Clear All
David R. Ryglicki, Daniel Hodyss, and Gregory Rainwater

the flow upwind of the convective cell and causing sinking. They noted ( Klemp and Wilhelmson 1978 , p. 1105), “The weak downdraft to the west of the updraft z = 2.25 km ([their] Fig.12) is possibly due to blocking westerly flow by the storm forcing the approaching air to descend rather than flow around the storm.” Fritsch and Maddox (1981) , in their analyses of upper-level observations of mesoscale convective complexes (MCC), noted the presence of mesohighs above the MCCs. While their

Restricted access
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

Restricted access
Patrick Duran and John Molinari

therein. Since ocean coupling and asymmetric forcing are present in nature, the intent of this paper is not to formally simulate Hurricane Patricia. Rather, the intent is to simulate a storm with a similar intensification rate and to examine the processes that produced the stability variations in the simulated storm. After an initial spinup period of about 20 h, the modeled storm ( Fig. 1 , blue lines) began an RI period that lasted approximately 18 h. After this RI, the storm continued to intensify

Full access
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

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

not contribute to stronger tangential winds at the surface, which may be due to the periodicity of the forcing and its concentrated location outside of the RMW. Heating anomalies in the current study extend a large horizontal distance in the upper troposphere, nearly 300 km long at later times in the extensive anvil of the Nightonly simulations (not shown). The expansive area of heating anomalies could contribute to a larger enhancement more similar to that reported by Navarro and Hakim (2016

Full access
Jonathan Martinez, Michael M. Bell, Robert F. Rogers, and James D. Doyle

can lead to more skillful intensity forecasts. A common theoretical and numerical framework employed to understand TC intensification is predicated on the balanced vortex model ( Eliassen 1951 ), whereby an axisymmetric vortex is assumed to continuously evolve in a state of gradient wind and hydrostatic balance in response to a specified (often time invariant) forcing. Within the balanced vortex framework, it has been shown that heating concentrated radially inward of the radius of maximum

Full access
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

Full access