real*8 function psvco2(T) C solid-vapor transition for CO2 C returns saturation pressure in Pascal, input is temperature in Kelvin implicit none real*8 T psvco2 = exp(23.3494 - 3182.48/T)*100. end real*8 function tfrostco2(p) C the inverse of function psvco2 C input is pressure in Pascal, output is temperature in Kelvin implicit none real*8 p c tfrostco2 = 1301.679/(6.81228-log10(p*1.e-5))+3.494 c tfrostco2 = -1352.6/(log10(p*0.01)-9.8318) tfrostco2 = 3182.48/(23.3494+log(100./p)) end C----------------------------------------------------------------------- C Antoine equation parameters from NIST, 154-186K C based on Giauque and Egan, 1937 c A=6.81228; B=1301.679; C=-3.494; c p=10.^(A-(B./(T+C)))*1.e5; C Expressions from Int. Crit. Tabl. 3.207, based on many references c psvco2 = 10**(-1352.6/T + 9.8318)*100. C -135C to -56.7C (138K - 216K) c p=10^(-0.05223*26179.3/T + 9.9082)*100.; C -183C to -135C (90K - 138K) c p=10^(-1275.62/T + 0.006833*T + 8.3071)*100; C -110 to -80C (163K - 193K) c p=10^(- 1279.11/T + 1.75*log10(T) - 0.0020757*T + 5.85242)*100; c p=10^(- 1352.6/T + 9.8318)*100; C Mars book values are systematically lower than Int. Crit. Tabl. values C Mars book, p959 c p=exp(23.3494 - 3182.48/T)*100.; % 120-160K c p=exp(25.2194 - 3311.57/T - 6.71e-3*T)*100; % 100-170K C Mars book p960, based on Miller & Smythe (1970) c p=exp(26.1228 - 3385.26/T - 9.4461e-3*T)*100; % 123-173K C-------------------------------------------------------------------------