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SURFEX v7.3
General documentation of Surfex
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SURFEX v7.3
General documentation of Surfex
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00001 ! ######### 00002 SUBROUTINE SUNPOS (KSIZE_OMP, KYEAR, KMONTH, KDAY, PTIME, & 00003 PLON, PLAT, PTSUN, PZENITH, PAZIMSOL) 00004 ! #################################################################################### 00005 ! 00006 !!**** *SUNPOS * - routine to compute the position of the sun 00007 !! 00008 !! PURPOSE 00009 !! ------- 00010 !! The purpose of this routine is to compute the cosine and sinus of the 00011 !! solar zenithal angle (angle defined by the local vertical at the position 00012 !! XLAT, XLON and the direction of the sun) and the azimuthal solar 00013 !! angle (angle between an horizontal direction (south or north according 00014 !! to the terrestrial hemisphere) and the horizontal projection of the 00015 !! direction of the sun. 00016 !! 00017 !!** METHOD 00018 !! ------ 00019 !! The cosine and sinus of the zenithal solar angle and the azimuthal 00020 !! solar angle are computed from the true universal time, valid for the (XLAT, 00021 !! XLON) location, and from the solar declination aPD_ICE(:)ngle of the day. There 00022 !! is a special convention to define the azimuthal solar angle. 00023 !! 00024 !! EXTERNAL 00025 !! -------- 00026 !! NONE 00027 !! 00028 !! IMPLICIT ARGUMENTS 00029 !! ------------------ 00030 !! 00031 !! REFERENCE 00032 !! --------- 00033 !! "Radiative Processes in Meteorology and Climatology" 00034 !! (1976) Paltridge and Platt 00035 !! 00036 !! AUTHOR 00037 !! ------ 00038 !! J.-P. Pinty * Laboratoire d'Aerologie* 00039 !! 00040 !! MODIFICATIONS 00041 !! ------------- 00042 !! Original 16/10/94 00043 !! Revised 12/09/95 00044 !! (J.Stein) 01:04/96 bug correction for ZZEANG 00045 !! (K. Suhre) 14/02/97 bug correction for ZLON0 00046 !! (V. Masson) 01/03/03 add zenithal angle output 00047 !------------------------------------------------------------------------------- 00048 ! 00049 !* 0. DECLARATIONS 00050 ! ------------ 00051 ! 00052 USE MODD_CSTS, ONLY : XPI, XDAY 00053 USE MODD_SURFEX_OMP, ONLY : NBLOCK, NBLOCKTOT, INIT_DIM 00054 ! 00055 USE YOMHOOK ,ONLY : LHOOK, DR_HOOK 00056 USE PARKIND1 ,ONLY : JPRB 00057 ! 00058 #ifdef AIX64 00059 USE OMP_LIB 00060 #endif 00061 ! 00062 IMPLICIT NONE 00063 ! 00064 #ifndef AIX64 00065 INCLUDE 'omp_lib.h' 00066 #endif 00067 ! 00068 !* 0.1 Declarations of dummy arguments : 00069 ! 00070 INTEGER, DIMENSION(:), INTENT(IN) :: KSIZE_OMP 00071 INTEGER, INTENT(IN) :: KYEAR ! current year 00072 INTEGER, INTENT(IN) :: KMONTH ! current month 00073 INTEGER, INTENT(IN) :: KDAY ! current day 00074 REAL, INTENT(IN) :: PTIME ! current time 00075 REAL, DIMENSION(:), INTENT(IN) :: PLON ! longitude 00076 REAL, DIMENSION(:), INTENT(IN) :: PLAT ! latutude 00077 ! 00078 REAL, DIMENSION(:), INTENT(OUT) :: PZENITH ! Solar zenithal angle 00079 REAL, DIMENSION(:), INTENT(OUT) :: PAZIMSOL ! Solar azimuthal angle 00080 REAL, DIMENSION(:), INTENT(OUT) :: PTSUN ! Solar time 00081 ! 00082 !* 0.2 declarations of local variables 00083 ! 00084 ! 00085 REAL :: ZUT ! Universal time 00086 ! 00087 REAL, DIMENSION(SIZE(PLON)) :: ZTUT ,! True (absolute) Universal Time 00088 ZSOLANG ,! Hourly solar angle 00089 ZSINAZI ,! Sine of the solar azimuthal angle 00090 ZCOSAZI ,! Cosine of the solar azimuthal angle 00091 ZLAT, 00092 ZLON, ! Array of latitudes and longitudes 00093 ZSINZEN, !Sine of zenithal angle 00094 ZCOSZEN !Cosine of zenithal angle 00095 INTEGER, DIMENSION(0:11) :: IBIS, INOBIS ! Cumulative number of days per month 00096 ! for bissextile and regular years 00097 REAL :: ZDATE ! Julian day of the year 00098 REAL :: ZAD ! Angular Julian day of the year 00099 REAL :: ZDECSOL ! Daily solar declination angle 00100 REAL :: ZA1, ZA2 ! Ancillary variables 00101 REAL :: ZTSIDER, 00102 ZSINDEL, !azimuthal angle 00103 ZCOSDEL !azimuthal angle 00104 ! 00105 INTEGER :: JI, JJ, INKPROMA 00106 INTEGER :: IINDX1, IINDX2 00107 REAL(KIND=JPRB) :: ZHOOK_HANDLE 00108 ! 00109 !------------------------------------------------------------------------------- 00110 ! 00111 !* 1. TO COMPUTE THE TRUE SOLAR TIME 00112 ! ------------------------------- 00113 ! 00114 IF (LHOOK) CALL DR_HOOK('SUNPOS',0,ZHOOK_HANDLE) 00115 ZUT = MOD( 24.0+MOD(PTIME/3600.,24.0),24.0 ) 00116 00117 INOBIS(:) = (/0,31,59,90,120,151,181,212,243,273,304,334/) 00118 IBIS(0:1) = INOBIS(0:1) 00119 DO JI=2,11 00120 IBIS(JI) = INOBIS(JI)+1 00121 END DO 00122 IF( MOD(KYEAR,4).EQ.0 .AND. (MOD(KYEAR,100).NE.0 .OR. MOD(KYEAR,400).EQ.0)) THEN 00123 ZDATE = FLOAT(KDAY + IBIS(KMONTH-1)) - 1 00124 ZAD = 2.0*XPI*ZDATE/366.0 00125 ELSE 00126 ZDATE = FLOAT(KDAY + INOBIS(KMONTH-1)) - 1 00127 ZAD = 2.0*XPI*ZDATE/365.0 00128 END IF 00129 00130 ZA1 = (1.00554*ZDATE- 6.28306)*(XPI/180.0) 00131 ZA2 = (1.93946*ZDATE+23.35089)*(XPI/180.0) 00132 ZTSIDER = (7.67825*SIN(ZA1)+10.09176*SIN(ZA2)) / 60.0 00133 ! 00134 !------------------------------------------------------------------------------- 00135 ! 00136 !* 2. COMPUTE THE SOLAR DECLINATION ANGLE 00137 ! ----------------------------------- 00138 ! 00139 ZDECSOL = 0.006918-0.399912*COS(ZAD) +0.070257*SIN(ZAD) & 00140 -0.006758*COS(2.*ZAD)+0.000907*SIN(2.*ZAD) & 00141 -0.002697*COS(3.*ZAD)+0.00148 *SIN(3.*ZAD) 00142 ZSINDEL = SIN(ZDECSOL) 00143 ZCOSDEL = COS(ZDECSOL) 00144 !------------------------------------------------------------------------------- 00145 ! 00146 !$OMP PARALLEL PRIVATE(INKPROMA,IINDX1,IINDX2) 00147 ! 00148 !$ NBLOCK = OMP_GET_THREAD_NUM() 00149 ! 00150 IF (NBLOCK==NBLOCKTOT) THEN 00151 CALL INIT_DIM(KSIZE_OMP,0,INKPROMA,IINDX1,IINDX2) 00152 ELSE 00153 CALL INIT_DIM(KSIZE_OMP,NBLOCK,INKPROMA,IINDX1,IINDX2) 00154 ENDIF 00155 ! 00156 DO JJ = IINDX1,IINDX2 00157 ! 00158 !* 3. LOADS THE ZLAT, ZLON ARRAYS 00159 ! --------------------------- 00160 ! 00161 ZLAT(JJ) = PLAT(JJ)*(XPI/180.) 00162 ZLON(JJ) = PLON(JJ)*(XPI/180.) 00163 ! 00164 !------------------------------------------------------------------------------- 00165 ! 00166 !* 4. COMPUTE THE TRUE SOLAR TIME 00167 ! ---------------------------- 00168 ! 00169 ZTUT(JJ) = ZUT - ZTSIDER + ZLON(JJ)*((180./XPI)/15.0) 00170 ! 00171 PTSUN(JJ) = MOD(PTIME -ZTSIDER*3600. +PLON(JJ)*240., XDAY) 00172 ! 00173 !------------------------------------------------------------------------------- 00174 !* 3. COMPUTES THE COSINE AND SINUS OF THE ZENITHAL SOLAR ANGLE 00175 ! --------------------------------------------------------- 00176 ! 00177 ZSOLANG(JJ) = (ZTUT(JJ)-12.0)*15.0*(XPI/180.) ! hour angle in radians 00178 ! 00179 ZCOSZEN(JJ) = SIN(ZLAT(JJ))*ZSINDEL + &! Cosine of the zenithal 00180 COS(ZLAT(JJ))*ZCOSDEL*COS(ZSOLANG(JJ)) ! solar angle 00181 ! 00182 ZSINZEN(JJ) = SQRT( 1. - ZCOSZEN(JJ)*ZCOSZEN(JJ) ) 00183 ! 00184 !------------------------------------------------------------------------------- 00185 ! 00186 !* 5. ZENITHAL SOLAR ANGLE 00187 ! -------------------- 00188 ! 00189 PZENITH(JJ) = ACOS(ZCOSZEN(JJ)) 00190 ! 00191 !------------------------------------------------------------------------------- 00192 ! 00193 !* 6. COMPUTE THE AZIMUTHAL SOLAR ANGLE (PAZIMSOL) 00194 ! -------------------------------------------- 00195 ! 00196 IF (ZSINZEN(JJ)/=0.) THEN 00197 !Azimuth is measured counter-opposite-clockwise from due south 00198 ZSINAZI(JJ) = - ZCOSDEL * SIN(ZSOLANG(JJ)) / ZSINZEN(JJ) 00199 ZCOSAZI(JJ) = (-SIN(ZLAT(JJ))*ZCOSDEL*COS(ZSOLANG(JJ)) & 00200 +COS(ZLAT(JJ))*ZSINDEL & 00201 ) / ZSINZEN(JJ) 00202 PAZIMSOL(JJ) = ATAN2(ZSINAZI(JJ),ZCOSAZI(JJ)) 00203 ELSE 00204 PAZIMSOL(JJ) = XPI 00205 ENDIF 00206 ! 00207 ENDDO 00208 ! 00209 !$OMP END PARALLEL 00210 ! 00211 IF (LHOOK) CALL DR_HOOK('SUNPOS',1,ZHOOK_HANDLE) 00212 !------------------------------------------------------------------------------- 00213 ! 00214 END SUBROUTINE SUNPOS
1.8.0
