On the Unusual Track and Intensification of Hurricanes Joaquin and Patricia During TCI-2015
Abstract
The goal of this project is to study (i) the unusual track, the early rapid intensification (RI),and the subsequent weakening and re-intensification of Hurricane Joaquin; and (ii) the unusualRI of Hurricane Patricia, both occurred during the ONR~s TCI-2015. The associated results willbe compared to the early RI and the subsequent weakening and re-intensification of HurricaneSandy (2012), and the unusual RI of Hurricane Wilma (2005), respectively.In this project, we examine the hypotheses that are modified from our previous ones. Thatis, (i) weak upper-level environmental inertial stability helps increase storm-scale outflows,thereby increasing the coupling of upper-level outflows with secondary circulations in theinner-core region, including updrafts in the eyewall and spiral rainbands; and (ii) strongeroutflows tend to not only protect warm air in the inner-core region from ventilation byenvironmental flows, but also spread it over the outer region, thereby reducing hydrostaticallythe meso-~-scale sea-level pressure field and facilitating larger-scale convergence in theplanetary boundary layer (PBL).Through examining the above hypotheses, we wish to address the following questions:(i) What are the impacts of larger-scale disturbances in the upper-level outflow layer onthe track, structural, and intensity changes of Joaquin through the distribution of upright andslantwise convection in the inner-core region?(ii) What are the roles of convective bursts and their associated upper outflow fluxes indetermining the RI and intensity changes of the two storms? How are they related to local SSTperturbations and the radial absolute angular momentum transport in the PBL?(iii) To what extent do the magnitude and altitude of a single or double warm cores dependon the vertical wind shear and inertial stability in the upper divergent outflow layer? and(iv) How are the upper outflow temperature gradient and outflow asymmetries linked tomeso-~ scale sea-level pressure falls and low-level radial inflow fluxes?The above questions will be addressed by analyzing the cloud-permitting simulations andTCI observations of the two storms, including trajectory analyses relating the upper-leveloutflows to SST anomalies. Successful completion of the project will improve ourunderstanding of the impact of larger-scale flows in the upper outflow layer on the track andintensity changes of hurricanes, and benefit operational prediction and high-resolutionnumerical modeling of tropical cyclones in general.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 03, 2017
- Source ID
- N000141712210
Entities
People
- Da-Lin Zhang
Organizations
- Office of Naval Research
- United States Navy
- University of Maryland