_RL leithD2fac, leithD4fac
leithD4fac=0.015625 _d 0*(viscC4leithD/pi)**6
leithD4fac=0.125 _d 0*(viscC4leithD/pi)**3
leithD4fac=0. _d 0
& SQRT(leith4fac*grdVrt+leithD4fac*grdDiv)*L5
& SQRT(leithD4fac*grdDiv)*L5
viscA4_Dlth(i,j)=(leith4fac*grdVrt+(leithD4fac*grdDiv))*L5
viscA4_DlthD(i,j)=((leithD4fac*grdDiv))*L5
viscA4_ZLth(i,j)=(leith4fac*grdVrt+(leithD4fac*grdDiv))*L5
viscA4_ZLthD(i,j)=(leithD4fac*grdDiv)*L5