AbstractSupercell thunderstorms are simulated using an idealized numerical model to analyze the effects of modifications to the environmental low-level wind profile on near-surface rotation. Specifically, the orientation, magnitude, and depth of the low-level vertical wind shear are modified in several suites of experiments and compared to control simulations with no vertical wind shear in the prescribed layer.The overall morphology of the simulated supercells is highly sensitive to even shallow changes in the low-level wind profile. Moreover, maximum near-surface vertical vorticity varies as the low-level wind profile is modified. The results suggest this is principally a consequence of the degree to which favorable dynamic forcing of negatively buoyant outow is superimposed upon the near-surface circulation maximum. Simulations with easterly shear and weaker storm-relative winds over the depth of the gust front promote forward-surging outow and smaller separation between the near-surface circulation maximum and mesocyclone aloft compared with other hodograph shapes. This promotes near-surface vertical vorticity intensification in these simulations. Similar trends in near-surface vertical vorticity as a function of low-level shear orientation are observed for varying shear layer depths and bulk shear magnitudes over the shear layer. The degree to which specific hodograph shapes promote strong near-surface rotation may vary with different deep-layer wind profiles or thermodynamic environments from those simulated here; however, this study concludes that favorable positioning of the near-surface circulation maximum and mesocyclone aloft are a necessary condition for supercell tornadogenesis and this positioning may be modulated by the low-level wind profile.
Journal of the Atmospheric Sciences – American Meteorological Society
Published: Dec 14, 2017
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.
All for just $49/month
Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.
Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.
It’s easy to organize your research with our built-in tools.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera