Auxiliary material for Paper 2005GL024283

Infrared measurements of atmospheric CH3CN

Armin Kleinbohl, Geoffrey C. Toon, Bhaswar Sen, and Jean-Francois L. Blavier
Jet Propulsion Laboratory, California Institute of
Technology, Pasadena, California, USA

Debra K. Weisenstein
Atmospheric and Environmental Research, Inc., Lexington,
Massachusetts, USA

Paul O. Wennberg
California Institute of Technology, Pasadena, California,
USA

Kleinbohl, A., G. C. Toon, B. Sen, J.-F. L. Blavier, D. K. Weisenstein, and P. O. Wennberg (2005), Infrared measurements of atmospheric CH3CN, Geophys. Res. Lett., 32, L23807, doi:10.1029/2005GL024283.

Introduction.

Included here are supplemental files that provide additional information
on the CH3CN pseudo-linelist, the modifications to CH4 line parameters
for lines in the vicinity of the main CH3CN absorption at 1463.3 cm-1,
and the 2-dimensional model used for the modeling of CH3CN profiles.
The supplement consists of three text files, two figures, and four tables:

text   : 2005GL024283-text_*.txt
figures: 2005GL024283-figure*.eps
tables : 2005GL024283-table*.txt


2005GL024283-text01.txt:

Text describing: 

1. Conditions of the CH3CN laboratory measurements
2. Derivation of the CH3CN pseudo-linelist
3. Accuracy of the CH3CN pseudo-linelist
4. References


2005GL024283-ts01.txt:

Table 1: Measurement conditions for the 29 CH3CN laboratory spectra
recorded at PNNL (T - Temperature, p_tot - total pressure,
p_ch3cn - CH3CN partial pressure), and scale factors of the CH3CN abundance
for each laboratory measurement retrieved with the CH3CN pseudo-linelist
in the frequency ranges of 870-1650 cm-1 and of 1462.0-1464.4 cm-1,
respectively.


2005GL024283-ts02.txt:

Table 2: Assumed vibrational frequencies (in cm-1) and degeneracies
for the CH3CN vibrational partition function.


2005GL024283-fs01.eps:

Figure 3: Fit of the transmittance of the laboratory spectrum
with the lowest absorption (#21, top) and the highest absorption
(#9, bottom). The symbols show the measured data while
the gray line indicates the fit. The residual is given as the
difference between measurement and fit in %.


2005GL024283-fs02.eps:

Figure 4: Similar to Fig. 3 (spectrum #21, top, spectrum #9, bottom)
but expanded to show the fit around the strongest CH3CN absorption
feature at 1463.3 cm-1. The dashed lines give the width of the window
used in the analyses of the atmospheric observations.


2005GL024283-text02.txt:

Text describing: 

1. CH4 laboratory measurements
2. Modifications of CH4 line parameters
3. Reference


2005GL024283-ts03.txt:

Table 3: Measurement conditions for the CH4 laboratory spectra
recorded at Kitt Peak National Solar Observatory
(Date - Date of recording (YYMMDD), T - Temperature,
p_tot - total pressure, p_ch4 - CH4 partial pressure,
l_cell - cell length).


2005GL024283-ts04.txt:

Table 4: Modifications of spectroscopic parameters of CH4
to the HITRAN04 data as suggested by the analysis of laboratory
measurements (Tag - HITRAN molecule and isotopologue number,
Frequency - Transition frequency in cm-1, Orig. Freq. - original
transition frequency in HITRAN for reference, Strength -
Line strength in cm-1/(molec.cm-2), ABHW - air broadened half width
in cm-1/atm, SBHW - self broadened half width in cm-1/atm, E" - Ground state
energy in cm-1, TD  - Exponent of temperature dependence of air width,
p_Shift - pressure shift in cm-1/atm). The modified quantities
are marked by underlining.


2005GL024283-text03.txt:

Text describing: 

1. 2-dimensional model simulations
2. References