Package ucar.nc2.geoloc.vertical

Class AtmosHybridSigmaPressure

  • All Implemented Interfaces:
    VerticalTransform
    @Immutable
public class AtmosHybridSigmaPressure
extends Object
    Implement CF "atmosphere_sigma_coordinate". 
     Atmosphere hybrid sigma pressure coordinate
 standard_name = "atmosphere_hybrid_sigma_pressure_coordinate"
 Definition
 p(n,k,j,i) = a(k)*p0 + b(k)*ps(n,j,i)
 or
 p(n,k,j,i) = ap(k) + b(k)*ps(n,j,i)

 where p(n,k,j,i) is the pressure at gridpoint (n,k,j,i), a(k) or ap(k) and b(k) are components of the hybrid
 coordinate at level k, p0 is a reference pressure, and ps(n,j,i) is the surface pressure at horizontal
 gridpoint (j,i) and time (n).

 The choice of whether a(k) or ap(k) is used depends on model formulation;
 the former is a dimensionless fraction, the latter a pressure value.
 In both formulations, b(k) is a dimensionless fraction.

 The format for the formula_terms attribute is
 formula_terms = "a: var1 b: var2 ps: var3 p0: var4"
 where a is replaced by ap if appropriate.

 The hybrid sigma-pressure coordinate for level k is defined as a(k)+b(k) or ap(k)/p0+b(k), as appropriate.
    See Also:
    "http://cfconventions.org/Data/cf-conventions/cf-conventions-1.9/cf-conventions.html#_atmosphere_hybrid_sigma_pressure_coordinate"