Number of particles in a unit volume-
The number of particles contained in a three dimensional space measuring once occupied by an object.
Nonhydrostatic model-
An atmospheric model in which the hydrostatic approximation is not made, so that the vertical momentum equation is solved. This allows nonhydrostatic models to be used successfully for horizontal scales of the order of 100 m, resolving small-scale mesoscale circulations such as cumulus convection and sea-breeze circulations. In recent years, computer power has made mesoscale weather prediction with nonhydrostatic models feasible, and several such models are in routine use by major meteorological modeling groups and operational centers.
Normal mode initialization-
A scheme that involves segregating high-frequency and low frequency components of the initial input data using horizontal and vertical structure functions for the initial atmosphere.
Nudging-
A four-dimensional data assimilation method that uses dynamical relaxation to adjust toward observations (observation nudging) or toward an analysis (analysis nudging).
NX-
ADAS Input NAMELIST variable: The number of grid points in the x-direction (generally east/west).
NY-
ADAS Input NAMELIST variable: The number of grid points in the y-direction (generally north/south).
NZ-
ADAS Input NAMELIST variable: The number of grid points in the vertical.
Nzsoil-
ADAS Input NAMELIST variable: The number of grid points in the vertical in the soil model.
Nstyps-
ADAS Input NAMELIST variable: The number of soil type.
Nchout-
ADAS Input NAMELIST variable: Fortran I/O channel number for history data output.
