1. Titan Airglow: FUV & EUV 2009 UVIS Spectra of Airglow During Day, Night & Eclipse :
JOSEPH AJELLO
JPL
MICHAEL STEVENS
NRL
ROBERT WEST
JACQUES GUSTIN
LPAP
GREG HOLSCLAW CU
TODD BRADLEY
UCF
Team meeting: Jan20112

3. TITAN PROTON PLASMA (0.1 keV-4 MeV) & SOLAR XUV GENERATES 2-level IONOSPHERE (300-1500 KM)
Solar XUV Excitation –Strong Top Ionosphere
-Magnetospheric: p and O+ Plasma Sporadic low ionosphere (Cravens et al., 2008).
S. Pol
South SS. POLE shelf

4. N2 Cross section Analysis for Dayglow VI (2)→UVIS (16)→Lab(e +N2 300 features)
V(z)=g(z) x w AURIC MODEL
gj (z) = F (e) x n(z) x s(e)
Dl=0.2Å
Dl=30Å
Dl=5Å DD

5. ISS & UVIS OBSERVATION OF TITAN SOLAR ECLIPSE @ 600K km
UV- VIS-near IR ( ) nm N2 night glow to 1000 km
plasma + N2

6. FUV T53 DARK SIDE RECORD 0 LIMB & DISK SPECTRA DOY110-2009 @15K km (MRH = SURFACE-800 KM)
polar

7. T53 EUV DARK SIDE RECORD 1 LIMB & DISK SPECTRA DOY110-2009 @15K km
-Spectrum =Eclipse at 20 x closer
-4-minute records
-Record 0 MRH = surface to 800 km
-Record 1;MRH = KM)
-NO Rayleigh scattering
Plasma excitation : km
-Molecular bands and NI ,II lines
-1/10 Intensity of Dayglow

8. Laboratory Result: p + N2

9. ELECTRON CROSS SECTIONS FOR TITAN DAYGLOW UV EMISSION MODEL
Stevens et al., 2011 “Production of Titan’s Far ions Ultraviolet Nitrogen Airglow”
AURIC Code Emission Cross Sections:
N2 Carroll-Yoshino c4′—X system,b‘-X, b-X systems
N I and N II multiplets
the N2 Lyman-Birge-Hopfield a—X system (Young et al., 2010)
the N2 Vegard-Kaplan A—X bands
sLBH=0.7 A&S (1985)

10. Pixel Center Ray Height (km)
Best (S/N) Titan Dayglow UVIS Limb Spectrum; 22June 2009: ‘800 km STARE’ Stevens et al., 2011
–40
One hour EUV and FUV image of 15 – 4 minute records .
–42
EUV
–44
DEC (deg)
–46
–48 4 2 –2 –4
RA (deg)
1500
1000
FUV
Pixel Center Ray Height (km)
500 10 20 30 40 50 60
Pixel Number

11. AURIC MODEL FIT TO UVIS EUV SPECTRUM AT 1000 KM

12. AURIC MODEL FIT TO UVIS FUV SPECTRUM AT 1000 KM

13. AURIC MODEL OF FUV VERs AND COLUMN EMISSION RATES

14. The FUV Dayglow Limb Spectra of Titan Tb Tangential Scan
Surface to Exosphere: 13Dec04.

15. DARK SIDE OBSERVATION OF TITAN ON 25MARCH2008

16. FUV LIMB PROFILE INTENSITIES OF 25 MARCH2009

17. Model fit to UVIS Dark Limb (Twilight) EUV Spectrum from 25Mar08 with a Regression Model - 7-Vectors)

18. How to get a BRIGHT UV Airglow in 2009
BRIGHTEST LIMB AIRGLOW 22JUNE obs[14]
SZA=53DEG, MRH =1000 km S/C ~60k KM
BRIGHTEST DISK & 2ND LIMB 12OCT OBS[45-51]
LIMB~ 1000KM
SZA~95, S/C ~175k KM

19. 2009 Observations from Lower Ionosphere Dark Limb (F0,F5) to Topside Bright Limb (F9, F14, F48)

20. SUMMARY OF 2009 ECLIPSE, LIMB, BRIGHT DISK AND DARK DISK UVIS OBSERVATIONS OF TITAN
Solar Driven processes on Dayside and Twilight
Observed EUV and FUV Emissions during 1 of 3 Eclipses. Probably Plasma impact.
Tentative Sporadic FUV Nightglow Spectra at 0.1 Intensity level of dayglow ( km). Probably Plasma Impact (protons, O+, electrons).
Twilight (Terminator) Glow-Solar XUV at deg Limb SZA ~ Dayside Intensity.
N2 EUV (12R) /FUV (200R) dayglow structure similar to Earth
Extend Published/Modeled spectra from Å

21. Elvis Lives (Titan Organic Chemistry-Biomarker
Elvis Lives (Titan Organic Chemistry-Biomarker! ) 45 years with my Honey