*ID TRADFIX 
*/ Do double sweep of N-S tracer advection to overcome
*/ instability problem when v>40m/s in polar winter.
*/ R G Jones 21/01/00
*/
*DECLARE TRACAD1A
*I TRACAD1A.465
! Do double sweep round N-S advection to ensure stability.

	DO I_SWEEP = 1 , 2

*D TRACAD1A.476
     &                    LATITUDE_STEP_INVERSE/2.

*I GSM6F404.9 
! End of N-S sweeps loop
        END DO
*/
