Recent Improvements to Resolved and Parameterized Gravity-Wave Dynamics in NAVGEM, the Navy’s Global Numerical Weather Prediction System

Steve Eckermann* and Stephen D. Eckermann, Jun Ma, Dave Broutman, Harold Knight, James D. Doyle, Kevin C. Viner, John P. McCormack, Timothy R. Whitcomb, Timothy F. Hogan, Karl W. Hoppel, David D. Kuhl, Benjamin C. Ruston, Nancy L. Baker, Ronald B. Smith, David C. Fritts, Michael J. Taylor, Andreas Dörnbrack

Space Science Division, Naval Research Laboratory, Washington DC

We review recent improvements in the description of resolved and parameterized gravity-wave dynamics in the Navy Global Environmental Model (NAVGEM), the Navy’s operational global numerical weather prediction system. Issues discussed are:

(1) a recent high-altitude (0-100 km) NAVGEM reanalysis for the austral winter of 2014 in support of the Deep-Propagating Gravity-Wave Experiment (DEEPWAVE);
(2) improvements in resolved gravity-wave dynamics through changes to the semi-implicit semi-Lagrangian (SISL) dynamical core;
(3) a stochastic parameterization of subgrid-scale nonorographic gravity-wave drag that transitioned to operations in 2015;
(4) a new parameterization of subgrid-scale orographic gravity-wave drag that accounts for the first time for the important (but previously omitted) influences of horizontal geometrical spreading on wave breaking and drag;
(5) examples of improved NAVGEM performance in comparison to gravity waves observed during DEEPWAVE.


*email: stephen.eckermann@nrl.navy.mil
*Preference: Oral