Ship and aircraft in situ observation-based column-averaged dry-air mixing ratios of CH4 (obs. XCH4) over the Western Pacific Ocean

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The dataset contains the timeseries of monthly model "blended observation-based XCH4" (blended obs. XCH4) over the Western Pacific Ocean from 2014 to 2018 for two representative latitude ranges: 30–40° N and 20–30° N. The dataset was obtained by integrating (mainly commercial) ship and aircraft observations with the aid of state-of-the art atmospheric chemistry-transport model calculations. The spatial and temporal coverage of the dataset will be continously extended and updated in the future.


Release date
Temporal coverage
2014/03/01 - 2017/07/31
Data provider
Email: cgerdb_admin(at)
File format
Data volume
15.4 KB
ver1.0 (Last updated: 2024/05/31)

Data Set

Column-averaged dry-air mixing ratios of CH4
[Region 1] Latitude: 30–40° N, Longitude: 130-150° E
[Region 2] Latitude: 20–30° N, Longitude: 130-150° E
Time resolution
1 month
Spatial resolution
Latitude: 10 degree
Longitude: 20 degree
Calculation method
In situ CH4 observations by cargo-ships of the Ship Of Opportunity Program (SOOP,, commercial aircrafts of the Comprehensive Observation Network for Trace gases by Airliner (CONTRAIL,, and by ship and aircraft of the Japan Meteorological Agency (JMA) are monthly averaged within 10° latitude by 20° longitude boxes over the ocean. The monthly averages are integrated with the aid of MIROC4 Atmospheric Chemistry-Transport Model (ACTM) calculations to obtain model blended observation-based CH4 profiles. Using equation (15) of Connor et al. (2008) (, and parameters of GOSAT (Greenhouse Gases Observing Satellite) retrievals, a "blended observation-based column-averaged CH4" (blended obs. XCH4) dataset is obtained. (
[Free keywords]
Greenhouse gas, Satellite validation, Carbon cycle, Climate Change, Methane, CH4, XCH4
Water-based Platforms > Vessels
Air-based Platforms > Jet > Airplane
Space-based Platforms > Earth Observation Satellites > GOSAT
Update history
Ver1.0 was released

Reference Information

Müller, A., Tanimoto, H., Sugita, T., Patra, P. K., Nakaoka, S., Machida, T., Morino, I., Butz, A., and Shiomi, K. (2024): Ship- and aircraft-based XCH4 over oceans as a new tool for satellite validation., doi:10.5194/amt-17-1297-2024.

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When this data set is referred to in publications, it should be cited in the following format.
Müller et al. (2024), Ship and aircraft in situ observation-based column-averaged dry-air mixing ratios of CH4 (obs. XCH4) over the Western Pacific Ocean,
verx.x *1, NIES, DOI:10.17595/20240531.001. (Reference date*2: YYYY/MM/DD)
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