FN Archimer Export Format PT J TI A Conservative Model for Nonlinear Dynamics in a Stratified, Rotating Fluid BT AF Filatoff, Nicolas Carton, Xavier AS 1:1;2:2; FF 1:;2:; C1 Ad Optimum Company, Paris, France (UBO/LOPS), Brest, France C2 AD OPTIMUM, FRANCE UBO, FRANCE UM LOPS TC 0 UR https://archimer.ifremer.fr/doc/00600/71195/69561.pdf LA English DT Article DE ;Incompressible and Stratified Fluids;Intermediate Model;Rossby Number;Burger Number;Conservation Properties;Energy;Potential Vorticity AB We present a set of equations describing the nonlinear dynamics of flows constrained by environmental rotation and stratification (Rossby numbers Ro∈[0.1,0.5] and Burger numbers of order unity). The fluid is assumed incompressible, adiabatic, inviscid and in hydrostatic balance. This set of equations is derived from the Navier Stokes equations (with the above properties), using a Rossby number expansion with second order truncation. The resulting model has the following properties: 1) it can represent motions with moderate Rossby numbers and a Burger number of order unity; 2) it filters inertia-gravity waves by assuming that the divergence of horizontal velocity remains small; 3) it is written in terms of a single function of space and time (pressure, generalized streamfunction or Bernoulli function); 4) it conserves total (Ertel) vorticity in a Lagrangian form, and its quadratic norm (potential enstrophy) at the model order in Rossby number; 5) it also conserves total energy at the same order if the work of pressure forces vanishes when integrated over the fluid domain. The layerwise version of the model is finally presented, written in terms of pressure. Integral properties (energy, enstrophy) are conserved by these layerwise equations. The model equations agree with the generalized geostrophy equations in the appropriate parameter regime. Application to vortex dynamics are mentioned. PY 2018 SO Open Journal of Marine Science SN 2161-7384 PU Scientific Research Publishing, Inc, VL 08 IS 02 BP 253 EP 275 DI 10.4236/ojms.2018.82013 ID 71195 ER EF