Identification

Title

Structure and dynamics of axisymmetric tornado-like vortices simulated with a semislip lower boundary

Abstract

No-slip boundary conditions are often employed in idealized axisymmetric models to study tornadoes. These boundary conditions result in a poor representation of near-ground winds, which are of crucial importance for tornadoes. In this study, the boundary layer of tornadoes is investigated using more realistic semislip conditions as the lower boundary of axisymmetric, idealized simulations. The drag law formulation of semislip conditions introduces the drag coefficient C d as a control parameter, alongside the swirl ratio S r (related to the system’s rotation) and a Reynolds number (describing diffusive effects) already employed in previous studies employing no-slip conditions. The exploration of a wide range of C d values shows that the analytical two-tiered potential vortex boundary layer is preserved under semislip conditions. The lower tier becomes shallower as C d decreases, finally vanishing for C d = 0.001. The drag coefficient plays a fundamental role in determining the structure of the vortex. A decrease in C d causes the same one-celled to two-celled transition previously observed for an increase of S r under no-slip conditions. For the range of swirl ratios and Reynolds numbers used in the present study, a decrease in C d leads to the intensification of the surface inflow and a reduced dissipation of angular momentum of parcels advected toward the center of the vortex. This intensification for decreasing C d occurs only for subcritical vortices; thus, the effect appears dependent on vortex structure and corner-flow swirl ratio.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.net/ark:/85065/d7gt5sks

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2025-04-01T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact