FRZLVL2.f File Reference

Subroutine that computes FRZING LVL, Z and RH. More...

Go to the source code of this file.

Functions/Subroutines
subroutine	frzlvl2 (isotherm, zfrz, rhfrz, pfrzl)
	FRZLVL2 computes FRZING LVL, Z and RH.

Detailed Description

Subroutine that computes FRZING LVL, Z and RH.

This routine computes the isothermal level height and relative humidity at this level for each mass point on the ETA grid. The computed isothermal level height is the mean sea level height. At each mass point we move up from the surface to find the last ETA layer where the temperature is less than isotherm and the temp in the layer below is above isotherm. Vertical interpolation in temperature to the isotherm temperature gives the isothermal level height. Pressure and specific humidity are interpolated to this level and along with the temperature provide the isothermal level relative humidity. If the entire atmosphere is below isotherm, the routine uses surface based fields to compute the relative humidity.

Note that in posting freezing level data the LFM look-alike file (IE, GRID 26), we pack 273.15K as the freezing temperature. All other output grids use 273.16K.

Program History Log

Date	Programmer	Comments
1992-12-22	Russ Treadon	Initial
1993-06-05	Russ Treadon	Corrected freezing level heights to be with respect to mean sea level, not above ground level
1995-03-10	Mike Baldwin	Get highest freezing level
1998-06-15	T Black	Conversion from 1-D to 2-D
1998-08-17	Mike Baldwin	Compute RH over ice if necessary
1998-12-22	Mike Baldwin	Back out RH over ice
2000-01-04	Jim Tuccillo	MPI version
2001-10-25	H Chuang	Modified to process hybrid model output
2002-01-15	Mike Baldwin	WRF version
2010-08-27	T. Smirnova	Added PFRZL to the output
2016-01-21	C. Alexander	Generalized function for any isotherm
2019-10-30	Bo Cui	Remove "GOTO" statement
2020-11-10	Jesse Meng	Use UPP_PHYSICS module
2021-10-15	JESSE MENG	2D DECOMPOSITION
2021-07-28	W. Meng	Restrict compuatation from undefined grids

Author

Russ Treadon W/NP2

Date

1992-12-22

Definition in file FRZLVL2.f.

Function/Subroutine Documentation

frzlvl2()

subroutine frzlvl2	(	real, intent(in)	isotherm,
		real, dimension(ista:iend,jsta:jend), intent(out)	zfrz,
		real, dimension(ista:iend,jsta:jend), intent(out)	rhfrz,
		real, dimension(ista:iend,jsta:jend), intent(out)	pfrzl
	)

FRZLVL2 computes FRZING LVL, Z and RH.

Parameters

[in]	ISOTHERM	real Isothermal value of height to be output.
[out]	ZFRZ	real Above ground level/ZFL at isotherm height.
[out]	RHFRZ	real Relative humidity at isotherm level.
[out]	PFRZL	real Pressure at isotherm level.

Definition at line 50 of file FRZLVL2.f.

Referenced by miscln().