partition_function_data.cc File Reference

Coefficients for 3rd order polynomial of partition function in temperature, plus safety check. More...

#include "arts.h"
#include "make_array.h"
#include "absorption.h"

Go to the source code of this file.

Defines
Some #defines for better readability
#define	Qcoeff   MakeArray<Numeric>
Functions
void	spec (Array< SpeciesRecord >::iterator &is, Array< IsotopeRecord >::iterator &ii, String name)
	Define partition function coefficients lookup data.
void	iso (Array< IsotopeRecord >::iterator &ii, String name, const ArrayOfNumeric &coeff)
void	define_partition_species_data ()

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Detailed Description

Coefficients for 3rd order polynomial of partition function in temperature, plus safety check.

This file contains the definition of this function and a safety check of the input. You have to add the coefficients of new species here, along with the new entry into the species_data (file species_data.cc) record, if you want to extend the capability of ARTS. These entries have to be in the same order, which is assured by check_q_data.

Author:

Axel von Engeln, C. Verdes,

Date:

2000-08-21

Definition in file partition_function_data.cc.

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Define Documentation

#define Qcoeff   MakeArray<Numeric>

Definition at line 59 of file partition_function_data.cc.

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Function Documentation

void define_partition_species_data

(

)

Definition at line 155 of file partition_function_data.cc.

void iso	(	Array< IsotopeRecord >::iterator &	ii,
		String	name,
		const ArrayOfNumeric &	coeff
	)

Definition at line 706 of file partition_function_data.cc.

void spec	(	Array< SpeciesRecord >::iterator &	is,
		Array< IsotopeRecord >::iterator &	ii,
		String	name
	)

Define partition function coefficients lookup data.

General Remarks

This function contains the polynomial coefficients of the partition function for each isotope of each species. The sorting of the array has to match the species_data entries, a safety check routine assures this order.

The information on the partition function are usually calculated using the latest version pf TIPS program, provided by B. Gamache. he latest TIPS code, TIPS_2003, can be obtained from the web page (http://faculty.uml.edu/robert_gamache/) in the Software and Data section. These include the data for all molecular species found in the 2000 HITRAN database, and, in addition, data for 13 other isotopomers/isotopologues of ozone and carbon dioxide. The calculations address the corrections suggested by Goldman et al. The calculations of the partition functions consider the temperature range 70--3000K, in steps of 25K to be applicable to a variety of remote sensing needs. The partition functions for any temperatures other than the ones at which the data is provided, are calculated by a Lagrange 4-point interpolation.

The coefficients for species which are not covered in HITRAN are calculated from JPL values. The JPL catalogue has a different way to calculate the partition function, it gives the partition function at specific temperatures: 300, 225, 150, 75, 37.5, 18.75, 9.375 K and an interpolation scheme is given for values inbetween. The partition functions are proportional to temperature T^1.5 for non-linear molecules (degrees of freedom: 3) and proportional to T for linear molecules (degrees of freedom 2). Nothing is known so far about the way how to treat atoms.

The polynomial coefficients for JPL catalogue values are calculated with a matlab program. This calculates the partition function for all temperatures between 70 and 500 K from the given JPL values, by using the recommended JPL interpolation scheme. JPL does not consider vibrational energy levels in the partition functions and a correction based on a literature research is performed within the idl program (for energy levels refer to that idl file). The literature research yielded only main isotope vibrational levels, since nothing better is available they were used for the isotopes as well. The idl program fits a polynomial to the data, and outputs the coefficients. The polynomial is fitted between temperatures of 70 to 500 K. No big difference is found in the ratio of the partition functions Q(300K)/Q(T) (the relevant quantity for the calculation of the JPL intensities to other temperatures) for other fit ranges, e.g., 9 - 300 K (range where the JPL partition functions are given), except for HCOOH, where the 0 to 300 K fit is better and was therefore use for this species (see below).

In order to see the level of agreement of the to partition functions datasets, HITRAN and JPL, a intercomparison has been made. It was found that, with some exceptions, the two datasets are in a good agreement, if a vibrational correction is applied to the JPL partition functions. Only for 16 molecules (out of 66 considered molecules), the deviations in the two datasets are larger than 1%. The largest discrepancies appear, for ClONO$_2$ (23% at 150~K). Some deviations, however much smaller (around 2%, or less), are found, e.g., for HCl, HOBr, and HBr.

Source for entries

Molecule Name:

Arts convention

Isotope Name:

Arts convention

Coefficients:

Generally taken from the new program provided by B. Gamache, version 2003. Partition functions for species included only in JPL, except for BrO, were calculated according to the JPL recommended scheme, and a 3rd order polynomial fit was performed (with the idl program mentioned above). The partition function data for BrO is provided by Agnes Perrin, Orsay, France.

Author:

Carmen Verdes

Date:

2003-11-12

Definition at line 688 of file partition_function_data.cc.