subroutine cal_sigma_v(ifreq,p0,wv,hwv,ta,gamma,sigma_v) integer ifreq real sigma_v,p0,wv,hwv,ta,gamma ! real wvc, wvcor(4) real sigv ! real voh1,otbar1,pbar1 real term21,term31,term41,term51,term61 real a11,a21,a31,a41,a51,a61 ! real voh2,otbar2,pbar2 real term22,term32,term42,term52,term62 real a12,a22,a32,a42,a52,a62 ! real voh3,otbar3,pbar3 real term23,term33,term43,term53,term63 real a13,a23,a33,a43,a53,a63 ! real voh4,otbar4,pbar4 real term24,term34,term44,term54,term64 real a14,a24,a34,a44,a54,a64 ! real const1,const2,const3,const4 real h1,h2,h3,h4 ! data const1,const2,const3,const4/0.6,2.8,0.2,0.2/ data h1,h2,h3,h4/5.0,4.9,6.8,6.4/ ! data a11,a21,a31,a41,a51,a61/-.13747e-2,-.43061e-4, .14618e+1, & .25101e-3, .14635e-1,-.18588e+3/ data a12,a22,a32,a42,a52,a62/ .22176e-1,-.32367e-4,-.10840e-4, & -.63578e-1, .16988e-7,-.29824e+2/ data a13,a23,a33,a43,a53,a63/-.10566e-2,-.12906e-3, .56975e+0, & .10828e-8,-.17551e-7, .48601e-1/ data a14,a24,a34,a44,a54,a64/-.60808e-2,-.70936e-3, .28721e+1, & .42636e-8,-.82910e-7, .26166e+0/ ! ! data wvcor/1.01,0.95,1.06,0.92/ data wvcor/1.02,0.98,1.02,0.88/ ! use modified water vapor value to correct for errors in theoretical absorption ! wvc = wv*wvcor(ifreq) ! if (ifreq.eq.1) then pbar1 = p0/(1.0 + hwv/h1) voh1 = wv/hwv term21 = a21*voh1 otbar1 = 1.0/(ta - const1*gamma*hwv) term31 = a31*otbar1 term61 = a61*otbar1*otbar1 term41 = a41*pbar1*otbar1 term51 = a51*voh1*otbar1 sigv = a11 + term21 + term31 + term41 + term51 + term61 else if (ifreq.eq.2) then pbar2 = p0/(1.0 + hwv/h2) term22 = a22*pbar2 term52 = a52*pbar2*pbar2 voh2 = wv/hwv term32 = a32*voh2 otbar2 = 1.0/(ta - const2*gamma*hwv) term42 = a42*otbar2 term62 = a62*otbar2*otbar2 sigv = a12 + term22 + term32 + term42 + term52 + term62 else if (ifreq.eq.3) then pbar3 = p0/(1.0 + hwv/h3) term43 = a43*pbar3*pbar3 voh3 = wv/hwv term23 = a23*voh3 otbar3 = 1.0/(ta - const3*gamma*hwv) term33 = a33*otbar3 term53 = a53*pbar3*voh3 term63 = a63*otbar3*voh3 sigv = a13 + term23 + term33 + term43 + term53 + term63 else if (ifreq.eq.4) then pbar4 = p0/(1.0 + hwv/h4) term44 = a44*pbar4*pbar4 voh4 = wv/hwv term24 = a24*voh4 otbar4 = 1.0/(ta - const4*gamma*hwv) term34 = a34*otbar4 term54 = a54*pbar4*voh4 term64 = a64*otbar4*voh4 sigv = a14 + term24 + term34 + term44 + term54 + term64 else sigv = 0.0 endif sigma_v = sigv*wvc end subroutine cal_sigma_v