Atmospheric Sulfur Hexafluoride Dry Air Mole Fraction at Nainital, India

Click Here to Download Click Here to Download

The dataset is SF6 dry air mole fraction in the air sample which is collected by the weekly flask sampling at Nainital, India since 2006.


Release date
Temporal coverage
2006/09/29 - 2020/12/30
Data provider
Email: cgerdb_admin(at)
File format
Data volume
72 KB
ver.2022.0 (Last updated: 2022/03/01)

Data Set

SF6 [ppt]
Observation period
From 2006/09/29 (ongoing)
29.36°N, 79.46°E
Elevation: 1940 m
Sampling height: 7 m above ground
Measurement method
Flask samples were collected from September 2006 in Nainital, India. Inlets were mounted at 7 m above ground level (on the roof of the second floor of the station) in Nainital. Air samples were collected once a week (usually on Wednesdays) at 14:00 LT into a 1.5 L Pyrex flask with two stopcocks sealed with Viton O-rings via a sampling line. The sampling line contained a diaphragm pump and a freezer for dehumidification by a glass trap. The sampling flow rate was approximately 2 L min−1, and the sample was passed through a −30 ℃ cooler and pressurized to 0.25 MPa after 10 min flushing through the sampling tube and flask. The sampled flasks were packed in a cardboard box and transported to the laboratory of the Center for Global Environmental Research (CGER), National Institute for Environmental Studies, Japan (NIES) (transportation period: 3–7 d), for analyses.
An air sample was passed through a −80 ℃ cold trap for dehumidification and was delivered to each instrument with a flow rate of 40 mL min−1. A gas chromatograph with an electron capture detector (GC-ECD) until 2011 and with a micro-electron capture detector (GC-micro-ECD) from 2012 (Agilent Technologies, HP-6890) were used to analyze.
Calculation method
The sample was injected into the analytical system three times per one flask, and the working standard gases were analyzed after every two flasks. Dry-air mole fractions were measured against each of their working standard gases, which were calibrated with NIES secondary standard gas series (SF6-NIES01 scale).
The mole fractions of the respective working standard gases are 4.65, 9.77, 14.53, and 19.08 ppt for SF6.
In Situ Land-based Platforms > Ground Stations
Atmosphere > Atmospheric Chemistry > Sulfur Compounds > Sulfur Hexafluoride
[Free keywords]
Nainital, India, Indo-Gangetic Plain, Himalaya, Sulfur Hexafluoride, SF6, NIES, Flask sampling
Update history
Dataset was created. ver.2022.0.


Project Manager
Shohei Nomura*1, Toshinobu Machida*1, Motoki Sasakawa*1, Manish Naja*2
*1 Earth System Division, NIES
*2 Aryabhatta Research Institute of Observational Sciences, India

Reference Information

Supplementary Materials
Nomura, S., Naja, M., Ahmed, M., K., Mukai, H., Terao, Y., Machida, T., Sasakawa, M., and Patra, P. K. (2021). Measurement report: Regional characteristics of seasonal and long-term variations in greenhouse gases at Nainital, India and Comilla, Bangladesh. Atmos. Chem. Phys., 21, 16427–16452, 2021, doi:10.5194/acp-21-16427-2021.

Terms and Conditions of Use*

*By accessing or using the Service you agree to follow these Terms. If you disagree with any part of the Terms, you may not access the Service.

Citation format
When this data set is referred to in publications, it should be cited in the following format.
Terao, Y., Nomura, S., Mukai, H., Machida, T., Sasakawa, M., and Naja, M. (2022), Atmospheric Sulfur Hexafluoride Dry Air Mole Fraction at Nainital, India, ver.xxxx.x *1, NIES, DOI:10.17595/20220301.011. (Reference date*2: YYYY/MM/DD)
*1 The version number is indicated in the data file.
*2 As the reference date, please indicate the date you downloaded the files.

Advisory Service

Advisory service
If you need scientific advice or expert opinion regarding the contents or scientific validity of this data set or Products derived from it, we can provide an advisory service based on an individual contract, different from the above one.
Depending on the extent of the help required, we can offer collaboration and/or supervision of the work based on the present data set. If you want to use our advisory service, contact the Data Provider.