edu.ucar.opensky::articles:43308 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T17:52:34.866099 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.net/ark:/85065/d7gt5sks https://doi.org/10.5065/D6RX99HX https Related Service #1 Cheyenne: SGI ICE XA Cluster Structure and dynamics of axisymmetric tornado-like vortices simulated with a semislip lower boundary 2025-04-01T00:00:00Z publication https://n2t.net/ark:/85065/d7gt5sks https://doi.org/10.1175/JAS-D-24-0096.1 Giove, S. author Rotunno, Richard author Cintolesi, C. author Miglietta, M. M. author UCAR/NCAR - Library publisher 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&#8217;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. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication <span style="font-family:Arial;font-size:10pt;font-style:normal;font-weight:normal;" data-sheets-root="1">Copyright 2025 American Meteorological Society (AMS).</span> None eng geoscientificInformation