Script hitran-scraper.py¶
usage: hitran-scraper.py [-h] [-t T] [M] [I] [llzero] [llfin]
Retrieves molecular lines from the HITRAN database [Gordon2016]
This script uses web scraping and the HAPI to save locally molecular lines from the HITRAN database.
While the HAPI provides the downloading facility, web scraping is used to get the lists of molecules
and isotopologues from the HITRAN webpages and get the IDs required to run the HAPI query.
The script is typically invoked several times, each time with an additional argument.
References:
[Gordon2016] I.E. Gordon, L.S. Rothman, C. Hill, R.V. Kochanov, Y. Tan, P.F. Bernath, M. Birk,
V. Boudon, A. Campargue, K.V. Chance, B.J. Drouin, J.-M. Flaud, R.R. Gamache, J.T. Hodges,
D. Jacquemart, V.I. Perevalov, A. Perrin, K.P. Shine, M.-A.H. Smith, J. Tennyson, G.C. Toon,
H. Tran, V.G. Tyuterev, A. Barbe, A.G. Császár, V.M. Devi, T. Furtenbacher, J.J. Harrison,
J.-M. Hartmann, A. Jolly, T.J. Johnson, T. Karman, I. Kleiner, A.A. Kyuberis, J. Loos,
O.M. Lyulin, S.T. Massie, S.N. Mikhailenko, N. Moazzen-Ahmadi, H.S.P. Müller, O.V. Naumenko,
A.V. Nikitin, O.L. Polyansky, M. Rey, M. Rotger, S.W. Sharpe, K. Sung, E. Starikova,
S.A. Tashkun, J. Vander Auwera, G. Wagner, J. Wilzewski, P. Wcisło, S. Yu, E.J. Zak,
The HITRAN2016 Molecular Spectroscopic Database, J. Quant. Spectrosc. Radiat. Transf. (2017).
doi:10.1016/j.jqsrt.2017.06.038.
positional arguments:
M HITRAN molecule number (default: (lists molecules))
I HITRAN isotopologue number (not unique, starts over at each
molecule) (default: (lists isotopologues))
llzero Initial wavelength (Angstrom) (default: None)
llfin Final wavelength (Angstrom) (default: None)
optional arguments:
-h, --help show this help message and exit
-t T Table Name (default: (molecular formula))
This script belongs to package pyfant
Usage examples¶
$ hitran-scraper.py
List of all HITRAN molecules
============================
ID Formula Name
---- --------- --------------------
1 H2O Water
2 CO2 Carbon Dioxide
3 O3 Ozone
4 N2O Nitrous Oxide
5 CO Carbon Monoxide
6 CH4 Methane
7 O2 Molecular Oxygen
8 NO Nitric Oxide
9 SO2 Sulfur Dioxide
10 NO2 Nitrogen Dioxide
11 NH3 Ammonia
12 HNO3 Nitric Acid
13 OH Hydroxyl Radical
14 HF Hydrogen Fluoride
15 HCl Hydrogen Chloride
16 HBr Hydrogen Bromide
17 HI Hydrogen Iodide
18 ClO Chlorine Monoxide
19 OCS Carbonyl Sulfide
20 H2CO Formaldehyde
21 HOCl Hypochlorous Acid
22 N2 Molecular Nitrogen
23 HCN Hydrogen Cyanide
24 CH3Cl Methyl Chloride
25 H2O2 Hydrogen Peroxide
26 C2H2 Acetylene
27 C2H6 Ethane
28 PH3 Phosphine
29 COF2 Carbonyl Fluoride
31 H2S Hydrogen Sulfide
32 HCOOH Formic Acid
33 HO2 Hydroperoxyl Radical
34 O Oxygen Atom
36 NO+ Nitric Oxide Cation
37 HOBr Hypobromous Acid
38 C2H4 Ethylene
39 CH3OH Methanol
40 CH3Br Methyl Bromide
41 CH3CN Methyl Cyanide
43 C4H2 Diacetylene
44 HC3N Cyanoacetylene
45 H2 Molecular Hydrogen
46 CS Carbon Monosulfide
47 SO3 Sulfur trioxide
Now, to list isotopologues for a given molecule, please type:
hitran-scraper.py <molecule ID>
where <molecule ID> is one of the IDs listed above.
Now suppose we want the molecule OH molecule:
$ hitran-scraper.py 13
List of all isotopologues for molecule 'OH' (Hydroxyl Radical)
==============================================================
m_formula ID ID_molecule Formula AFGL_Code Abundance
----------- ---- ------------- --------- ----------- ---------------
OH 1 13 (16)OH 61 0.997473
OH 2 13 (18)OH 81 0.002
OH 3 13 (16)OD 62 1.553710 × 10-4
Now, to download lines, please type:
hitran-scraper.py 13 <isotopologue ID> <llzero> <llfin>
where <isotopologue ID> is one the numbers from the 'ID' column above,
and [<llzero>, <llfin>] defines the wavelength interval in Angstrom.
Now selecting the first isotopologue and specifying the visible wavelength range:
$ hitran-scraper.py 13 1 3000 7000
Isotopologue selected:
======================
Field name Value
------------ --------
m_formula OH
ID 1
ID_molecule 13
Formula (16)OH
AFGL_Code 61
Abundance 0.997473
Wavelength interval (air): [3000.0, 7000.0] Angstrom
Wavenumber interval (vacuum): [14289.61969369552, 33342.42546386186] cm**-1
Table name: '(16)OH'
Fetching data...
===
=== BEGIN messages from HITRAN API ===
===
BEGIN DOWNLOAD: (16)OH
65536 bytes written to ./(16)OH.data
65536 bytes written to ./(16)OH.data
65536 bytes written to ./(16)OH.data
65536 bytes written to ./(16)OH.data
65536 bytes written to ./(16)OH.data
65536 bytes written to ./(16)OH.data
65536 bytes written to ./(16)OH.data
65536 bytes written to ./(16)OH.data
65536 bytes written to ./(16)OH.data
65536 bytes written to ./(16)OH.data
Header written to ./(16)OH.header
END DOWNLOAD
Lines parsed: 3855
PROCESSED
===
=== END messages from HITRAN API ===
===
...done
Please check files '(16)OH.header', '(16)OH.data'
Quick note on the HITRAN API¶
The files created (‘(16)OH.header’, ‘(16)OH.data’) can be opened using the HAPI.
They are also accessed by the application convmol.py.
The HAPI can be downloaded, but one version is also included with the f311 package. The following is an example of how the HITRAN data could be accessed from the Python console:
>>> from f311 import hapi
>>> hapi.loadCache()
Using .
(16)OH
Lines parsed: 3855
>>> oh_data = hapi.LOCAL_TABLE_CACHE["(16)OH"]
>>> oh_data.keys()
dict_keys(['data', 'header'])
>>> oh_data["data"].keys()
dict_keys(['ierr', 'gpp', 'molec_id', 'global_lower_quanta', 'sw', 'gamma_self', 'n_air', 'elower', 'line_mixing_flag', 'local_lower_quanta', 'gp', 'global_upper_quanta', 'gamma_air', 'local_upper_quanta', 'iref', 'local_iso_id', 'delta_air', 'nu', 'a'])
To work properly with these data in your code, you may have a look at the HAPI source code and manual, as this library is superbly documented.
Within f311, the code in f311.convmol.conv_hitran.hitran_to_sols() contains a usage example of HITRAN data.