!copyright (C) 2001 MSC-RPN COMM %%%RPNPHY%%%
***S/P SUNCOS
*
#include "phy_macros_f.h"
SUBROUTINE SUNCOS(SCOS,LMX,XLAT,XLON,HZ,DATE,IDATIM) 6
#include "impnone.cdk"
INTEGER IDATIM(14),I,LMX
REAL XLAT(LMX),XLON(LMX),SCOS(LMX),HZ,DATE
REAL DH,SDEC,CDEC,RDEC,AJOUR
REAL A,EOT
*
*Author
* L.Garand (1989)
*
*Revision
* 001 G.Pellerin(Mar90)Standard documentation
* 002 N. Brunet (May91)
* New version of thermodynamic functions
* and file of constants
* 003 L. Garand (Fev95) Add equation of time
* 004 J.P. Toviessi (June 2003) - IBM conversion
* - calls to vscos, vssin routine (from massvp4 library)
* - unnecessary calculations removed
*
*Object
* to calculate the cosines of the solar angle for LMX
* points
*
*Arguments
*
* - Output -
* SCOS cosines of the solar angle
*
* - Input -
* LMX number of points
* XLAT latitude in radians
* XLON longitude in radians
* HZ Greenwich hour (0 to 24)
* DATE julian day (0 to 366) (real number)
* IDATIM time coded in standard RPN format
*
**
*
*
#include "consphy.cdk"
C
*
AUTOMATIC ( tmcos , REAL , (LMX) )
AUTOMATIC ( tmsin , REAL , (LMX) )
*
IF(DATE.NE.0.) AJOUR=DATE
IF(DATE.EQ.0.) AJOUR=30.4*(IDATIM(2)-1)+IDATIM(3)
RDEC=0.412*COS((AJOUR+10.)*2.*PI/365.25 -PI)
SDEC=SIN(RDEC)
CDEC=COS(RDEC)
c correction for "equation of time"
A = DATE/365.*2.*PI
c in minutes
EOT = .002733 -7.343*sin(a)+ .5519*cos(a) -9.47*sin(2.*a)
x -3.02*cos(2.*a) -.3289*sin(3.*a) -.07581*cos(3.*a)
x -.1935*sin(4.*a) -.1245*cos(4.*a)
c express in a fraction of hour
EOT=EOT/60.
c express in radians
EOT=EOT*15.*PI/180.
c
call VSCOS(tmcos,XLAT(1),LMX)
call VSSIN(tmsin,XLAT(1),LMX)
*
DO 1 I=1,LMX
DH=HZ*PI/12. +XLON(I) -PI + EOT
SCOS(I)=AMAX1(tmsin(I)*SDEC + tmcos(I)*CDEC*
X COS(DH) , 0.00001)
C
1 CONTINUE
RETURN
END