Observational Data of Atmospheric O3 Mixing Ratios at Mt. Happo Observatory

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This dataset is time series data of atmospheric ozone (O3) mixing ratios measured at Mt. Happo Observatory situated in Nagano Prefecture, Japan. The observatory is located in the mountainous area (1850 m a.s.l.) near the Sea of Japan coast, and has been used for the observations of long-range transport of trace gases and aerosols from the Asian continent.


Release date
Temporal coverage
2012/06/18 - 2016/12/31
Data provider
Email: cgerdb_admin(at)nies.go.jp
File format
Data volume
268 KB
ver.2021-1.1 (Last updated: 2022/04/15)

Data Set

O3 mixing ratio
Observation period
From 2012/06/18 (ongoing)
36.7°N, 137.8°E
Elevation: 1850 m
Sampling height: 6 m above ground
Measurement method
Ambient air is continuously drawn from the top of an air sampling inlet (6 m above the ground level) through a glass manifold by a pumping blower, and then directed to the O3 instrument by means of a passivated Teflon tubing. The mixing ratios of O3 are determined using photometric instruments based on absorption in the ultraviolet region. The O3 instruments have been directly scaled to the primary standard, the Standard Reference Photometer (SRP) 35 once a year.
Calculation method
O3 mixing ratio values measured at 1-minute intervals are recorded. The hourly values are calculated by averaging all the 1-minute values in hour.
In Situ Land-based Platforms > Ground Stations
Atmosphere > Atmospheric Chemistry > Oxygen Compounds > Atmospheric Ozone > Ozone Surface
Atmosphere > Air Quality > Tropospheric Ozone
Update history
A new data set for the period between 2014 and 2016 has been added, as ver.2021-1.1.
The data in 2012, 2013 are released, as ver.2021-1.0


Project Manager
Data Manager

Reference Information

Okamoto, S., Tanimoto, H., Hirota, N., Ikeda, K., & Akimoto, H. (2018). Decadal shifts in wind patterns reduced continental outflow and suppressed ozone trend in the 2010s in the lower troposphere over Japan. Journal of Geophysical Research: Atmospheres, 123, 12,980– 12,993, doi:10.1029/2018JD029266.

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The author of this data set (hereafter "Author") agrees to the use of this data set by person(s) wishing to use the data (hereafter "User") as stipulated in the Terms and Conditions below.

Scope of consent
The User may re-distribute the data to third party without any change or transformation of the data, and may publish new intellectual products (hereafter "Products") based on this data set.
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The User shall not accept any compensation for the re-distribution of the data of this data set to a third party.
In the event that the User re-distributes the data of this data set to a third party, the same Terms and Conditions apply also to the re-distributed data set.
When the User re-distributes the data of this data set to a third party, the User is obliged to inform the third party about the URL of the original data set, the Terms and Conditions of Use, and the fact that the data set is continuously updated by the Author.
Use of the latest version
Unless special reason exists, the User shall use the latest version of this data set.
Citation policy
When publishing any Products based on the present data set, it must be clearly stated that the present data set was used.
However, the Author may request the User to delete the citation from the Product. In that case, the User shall comply with the request within reasonable extent.
Citation format
When this data set is referred to in publications, it should be cited in the following format.
Tanimoto et al. (2021), Observational Data of Atmospheric O3 Mixing Ratios at Mt. Happo Observatory, ver.xxxx-x.x*1, NIES, DOI:10.17595/20210709.001. (Reference date*2: YYYY/MM/DD)
*1 The version number is indicated in the name of each data file.
*2 As the reference date, please indicate the date you downloaded the files.
When mentioning the NIES observations of surface O3 at Mt. Happo, refer to Okamoto et al. (2018).
Utilization reporting
Re-distribution of the data or release of Products derived from the data set, shall be reported to the Data Provider without delay.
Error reporting
Any error in the data set, or the suspicion thereof, should be immediately reported to the Data Provider.
The Author and the Data Provider shall not have any liability or responsibility whatsoever for any damage that may arise from the use of this data set, and the User must not imply that any guarantee is provided by the Author or the Data Provider. Any injury or loss arising from the use of this data set is solely the responsibility of the User.

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