DEWPOINT.f File Reference

Subroutine that computes dewpoints from vapor pressure. More...

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Functions/Subroutines
subroutine	dewpoint (vp, td)
	DEWPOINT() Subroutine that computes dewpoints from vapor pressure.

Detailed Description

Subroutine that computes dewpoints from vapor pressure.

This routine is to computes the dewpoints for the N values of vapor pressure in array VP. The forumla:

VP = 0.611 * (X**A) * EXP( (A+B)*(1-X) )

is used to get dewpoint temperature T, where

X = T3/T, T3=Triple PT temperature, VP=Vapor pressure in CBS, 0.611=VP at T3, A=(Spec. HT. of WATER-CSUBP of vapor)/gas const of vapor and B=Latent heat at T3/(gas const of vapor times T3).

on the first call, a table TDP is constructed giving dewpoint as a function of vapor pressure.

Values of VP less than the first table entry (RVP1 in the code) will be given dewpoints for that beginning valus. Similarly, VP vaules that exceed the maximum table value (RVP2 in the code) will be assigned dewpoints for that maximum value.

The values 0.02 and 8.0 for RVP1 and RVP2 yield dewpoints of 233.6K and 314.7K,respectively.

Parameters

[in]	VP	Array of N vapor pressures(centibars).
[out]	TD	Dewpoint in degrees absolute.

Program history log:

Date	Programmer	Comments
1990-05-19	Jim Tuccillo	Initial
1993-05-12	R Treadon	Expanded table size and reset range of pressures covered by table.
1998-06-12	T Black	Conversion from 1-D to 2-D
2000-01-04	Jim Tuccillo	MPI Version
2021-07-26	W Meng	Restrict computation from undefined grids
2021-10-31	J Meng	2D Decomposition

Author

Jim Tuccillo W/NP2

Date

1990-05-19

Definition in file DEWPOINT.f.

Function/Subroutine Documentation

dewpoint()

subroutine dewpoint	(	real, dimension(ista:iend,jsta:jend), intent(in)	vp,
		real, dimension(ista:iend,jsta:jend), intent(out)	td
	)

DEWPOINT() Subroutine that computes dewpoints from vapor pressure.

It computes the dewpoints for the N values of vapor pressure in array VP.

Parameters

[in]	VP	Array of N vapor pressures(centibars).
[out]	TD	Dewpoint in degrees absolute.

Definition at line 51 of file DEWPOINT.f.

Referenced by caldwp(), and surfce().