Electronic Resource
Advective Mixing in a Nondivergent Barotropic Hurricane Model
| العنوان: | Advective Mixing in a Nondivergent Barotropic Hurricane Model |
|---|---|
| المؤلفون: | NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF METEOROLOGY, Rutherford, B, Dangelmayr, G, Persing, J, Schubert, W H, Montgomery, M T |
| المصدر: | DTIC |
| بيانات النشر: | 2010-01-20 |
| نوع الوثيقة: | Electronic Resource |
| مستخلص: | This paper studies Lagrangian mixing in a two-dimensional barotropic model for hurricane-like vortices. Since such flows show high shearing in the radial direction particle separation across shear-lines is diagnosed through a Lagrangian field, referred to as R-field, that measures trajectory separation orthogonal to the Lagrangian velocity. The shear-lines are identified with the level-contours of another Lagrangian field, referred to as S-field, that measures the average shear-strength along a trajectory. Other fields used for model diagnostics are the Lagrangian field of finite-time Lyapunov exponents (FTLE-field), the Eulerian Q-field, and the angular velocity field. Because of the high shearing, the FTLE-field is not a suitable indicator for advective mixing and in particular does not exhibit ridges marking the location of finite-time stable and unstable manifolds. The FTLE-field is similar in structure to the radial derivative of the angular velocity. In contrast, persisting ridges and valleys can be clearly recognized in the R-field, and their propagation speed indicates that transport across shear-lines is caused by Rossby waves. A radial mixing rate derived from the R-field gives a time-dependent measure of flux across the shearlines. On the other hand, a measured mixing rate across the shear-lines, which counts trajectory crossings, confirms the results from the R-field mixing rate, and shows high mixing in the eyewall region after the formation of a polygonal eyewall which continues until the vortex breaks down. The location of the R-field ridges elucidates the role of radial mixing for the interaction and breakdown of the mesovortices shown by the model. Published in Atmospheric Chemistry and Physics, v10 p475-497, 2010. |
| مصطلحات الفهرس: | Meteorology, ADVECTION, HURRICANES, MIXING, LAGRANGIAN FUNCTIONS, ROSSBY WAVES, RUNGE KUTTA METHOD, SHEAR PROPERTIES, TIME DEPENDENCE, TRAJECTORIES, VORTICES, BAROTROPIC MODELS, HYPERBOLIC MIXING, HYPERBOLICITY, LAGRANGIAN FIELDS, LAGRANGIAN MIXING, LCS(LAGRANGIAN COHERENT STRUCTURES), MIXING RATE, PARTICLE SEPARATION, SCALAR FIELDS, TWO DIMENSIONAL MODELS, VORTEX BREAKDOWN, Text |
| URL: | |
| الاتاحة: | Open access content. Open access content Approved for public release; distribution is unlimited. |
| ملاحظة: | text/html English |
| Other Numbers: | DTICE ADA554500 832131120 |
| المصدر المساهم: | From OAIster®, provided by the OCLC Cooperative. |
| رقم الانضمام: | edsoai.ocn832131120 |
| قاعدة البيانات: | OAIster |
| الوصف غير متاح. |