Abstract
We analyzed 12 years (2005–2016) of continuous measurements of atmospheric CO
 
 
 
 
 2
 
 
 
 and CH
 
 
 
 
 4
 
 
 
 concentrations made at nine tower observation sites in the Japan–Russia Siberian Tall Tower Inland Observation Network (JR-STATION), located in Siberia. Since the data are very noisy and have a low temporal resolution due to gaps in instrument operation, we used the recently developed Prophet model, which was designed to handle the common features of time series (multiple strong seasonalities, trend changes, outliers) and has a robust performance in the presence of missing data and trend shifts. By decomposing each sampled time-series into its major components (i.e., annual trend and seasonal, weekly, and hourly variation), we observed periodically changing patterns of tracer concentrations. Specifically, we detected multi-year variability of tracers and identified high-concentration events. The frequency of such events was found to vary throughout the year, reaching up to 20% of days for some months, while the number of such events was found to be different for CO
 
 
 
 
 2
 
 
 
 and CH
 
 
 
 
 4
 
 
 
 . An analysis of weather conditions showed that, in most cases, high-concentration events were caused by a temperature inversion and low wind speed. Additionally, wind directions were found to be different for high- and low-concentration events. For some sites, the wind direction indicated the location of strong local sources of CO
 
 
 
 
 2
 
 
 
 and CH
 
 
 
 
 4
 
 
 
 . As well as elucidating the seasonality of greenhouse gas concentrations, this study confirmed the potential of the Prophet model for detecting periodicity in environmental phenomena.
Highlights
Detailed information on the distribution of sources and sinks of the atmospheric greenhouse gases (GHGs) CO2 and CH4 is a prerequisite for analyzing and understanding the role of the carbon cycle within the context of global climate change
The Prophet model was implemented to analyze the time-series measured at towers in the JR-STATION, Siberia (Table 1).The trend and seasonal variation of the time-series analyzed in the present study have been analyzed for individual sites in past publications
We present a time-series analysis of composite CO2 and CH4 concentration records from nine tower measurement sites in Siberia
Summary
Detailed information on the distribution of sources and sinks of the atmospheric greenhouse gases (GHGs) CO2 and CH4 is a prerequisite for analyzing and understanding the role of the carbon cycle within the context of global climate change. Within the context of global climate change, accurate continuous long-term measurements in Siberia are crucial for estimating global CO2 and CH4 budgets due to potential changes in natural emissions from the biosphere, wetlands, thawing lakes, and melting permafrost. In 2002, the National Institute for Environmental Studies (NIES) began a cooperative project for the continuous measurement of greenhouse gases in West Siberia called the Japan–Russia Siberian Tall Tower. The number of observational sites has been progressively expanded, and the network consists of nine towers, eight located in West Siberia and one located in Yakutsk, East Siberia [3]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
