& externForcingCycle, externForcingPeriod,
_RL externForcingPeriod
gchem_ForcingPeriod=externForcingPeriod
nForcingPeriods = NINT(externForcingCycle/externForcingPeriod)
Ifprd = NINT(externForcingPeriod*rdt)
CALL WRITE_0D_RL( externForcingPeriod, INDEX_NONE,
& periodicExternalForcing, externForcingPeriod, externForcingCycle,
IF ( externForcingCycle*externForcingPeriod .EQ. 0. ) THEN
IF ( INT(externForcingCycle/externForcingPeriod) .NE.
& externForcingCycle/externForcingPeriod ) THEN
IF ( externForcingCycle.lt.externForcingPeriod ) THEN
IF ( externForcingPeriod.lt.deltaTclock ) THEN
externForcingPeriod = 0.
CFC_forcingPeriod = externForcingPeriod
& int(externForcingCycle/externForcingPeriod+0.5)
Ifprd=int(externForcingPeriod*rdt+0.5)
nForcingPeriods=int(externForcingCycle/externForcingPeriod+0.5)
DIC_forcingPeriod = externForcingPeriod