C Subroutine QBACK C C This software is part of the GLOW model. Use is governed by the Open Source C Academic Research License Agreement contained in the file glowlicense.txt. C For more information see the file glow.txt. C C Stan Solomon, 11/88, 11/92 C Comment updated 3/05 C C Estimates background ("nighttime") ionization rates. C Intended to conform to the TIGCM background (Roble et al., 1989). C Three fluxes, from the stellar background and multiple scattering C of solar atomic hydrogen emissions in the geocorona, are considered: C The sum of ionizing flux in the 100-1000 A range (FIONT) C H Lyman beta (FLYBT) C H Ly alpha (FLYAT) C SUBROUTINE QBACK (ZMAJ, ZNO, ZVCD, PHOTOI, PHONO, JM, NMAJ, NST) C DIMENSION ZMAJ(NMAJ,JM), ZNO(JM), ZVCD(NMAJ,JM), + PHOTOI(NST,NMAJ,JM), PHONO(NST,JM) C DATA FIONT/5.0E7/, FLYBT/1.0E7/, FLYAT/1.0E9/ DATA SIGIO/1.0E-17/, SIGIO2/2.0E-17/, SIGIN2/2.0E-17/, + SLBAO2/1.6E-18/, SLBIO2/1.0E-18/, SLAAO2/1.0E-20/, + SLAINO/2.0E-18/ C C Calculate ionization rates at each altitude: C DO 200 J=1,JM TAUI = 2.*(SIGIO*ZVCD(1,J)+SIGIO2*ZVCD(2,J)+SIGIN2*ZVCD(3,J)) IF (TAUI .GT. 60.) TAUI = 60. TAULYB = 2.*SLBAO2*ZVCD(2,J) IF (TAULYB .GT. 60.) TAULYB = 60. TAULYA = 2.*SLAAO2*ZVCD(2,J) IF (TAULYA .GT. 60.) TAULYB = 60. FION = FIONT * EXP(-TAUI) PHOTOI(1,1,J) = PHOTOI(1,1,J) + FION * ZMAJ(1,J) * SIGIO PHOTOI(1,2,J) = PHOTOI(1,2,J) + FION * ZMAJ(2,J) * SIGIO2 + + FLYBT * EXP(-TAULYB) * ZMAJ(2,J) * SLBIO2 PHOTOI(1,3,J) = PHOTOI(1,3,J) + FION * ZMAJ(3,J) * SIGIN2 PHONO(1,J) = PHONO(1,J) + FLYAT * EXP(-TAULYA) * ZNO(J) * SLAINO 200 CONTINUE C RETURN END