The absorption spectrum of phosphine (PH3) between 2.8 and 3.7μm: Line positions, intensities, and assignments

High-resolution spectroscopy of Saturn at 3 microns: CH4, CH3D, C2H2, C2H6, PH3, clouds, and haze

“…Kerola et al (1997) derived an upper limit of ∼10 −9 to the mixing ratio near 400 mbar from the 3.0 µm region of their Kuiper Airborne Observatory spectra of Saturn. Using the same spectral range from our data and the HITRAN NH 3 line list, we derive upper limits of 6 × 10 −8 at 460 mbar and 3 × 10 −8 at 390 mbar, which are significantly higher than the upper limit of Kerola et al While we are uncertain how Kerola et al derived their upper limit, it should be noted that they did not have access to the excellent line-by-line PH 3 model of Butler et al (2006); this difference might explain their tighter limit. Our upper limits to the mixing ratios do not allow us to determine if NH 3 is significantly sub-saturated, when we compare our values to, e.g., the saturation curve presented in Fig.…”

“…KG used an ab initio model to analyze the PH 3 spectral features observed at low resolution between 2.9 and 3.1 µm. Butler et al (2006) have now compiled molecular line parameters for a total of 3980 assigned lines of eight PH 3 bands: 3ν 2 (3.400 µm), 2ν 2 + ν 4 (3.241 µm), ν 2 + 2ν 4 (3.111 µm), ν 1 + ν 2 (3.023 µm), ν 2 + ν 3 (3.201 µm), ν 1 + ν 4 (2.918 µm), and ν 3 + ν 4 (2.913 µm); although not for 3ν 4 , a weak band in a highly congested area at ∼2.990 µm.…”

“…The rotational constants are not available in the literature, although the band type has been recognized as perpendicular for a symmetric top molecule by Smith (1949). According to Herzberg (1945, p. 344), the band is designated as Rothman et al (2005) 4.5 × 10 −3b,c (troposphere and stratosphere) PH 3 0.075 (300/T ) 0.83d Butler et al (2006) 1.75 × 10 −5 p 1.95 (p in bars) e CH 3 D 0.075 (300/T ) 0.5f KG 2.5-4.5 × 10 −7b (troposphere and stratosphere) 0.075 (300/T ) 0.5f This work 2.5 × 10 −7b (troposphere and stratosphere) C 2 H 2 0.093 (294/T ) 0.75g HITRAN2004, Rothman et al (2005) 3.4 × 10 −7h (stratospheric cutoff ∼ 15 mbar) C 2 H 6 (ν 7 ) 0.115 (296/T ) 0.942i Kim (2003) 9 ± 4 × 10 −6 (∼µbar) (ν 3 + ν 9 + ν 11 ) 0.115 (296/T ) 0.942i This work 6.7 + 3.3/−2.3 × 10 −6j (stratospheric cutoff ∼ 10 mbar) a Fox et al (1988). b Lellouch et al (2001).…”

The HITRAN2012 molecular spectroscopic database

“…Spectral line parameters for new bands of PH 3 have been added in the region from 2724 to 3602 cm -1 , based on the work of Butler et al [255]. In addition, the collision-broadened 39 parameters of the previously existing data in HITRAN from 770 to 2472 cm -1 have been updated using Ref.…”

“…In addition, the collision-broadened 39 parameters of the previously existing data in HITRAN from 770 to 2472 cm -1 have been updated using Ref. [255]. A recent global study of PH 3 [256] has confirmed the need to improve and normalize the calculated intensities for the bands at 5 and 3 μm.…”