Research result data XCO2SAT+ P06 ALT8 2022-01-13
Scope: In our Manuscript we describe a novel method (referred to as XCO2SAT+) for deriving time series of XCO2 concentrations for selected locations in Germany based on long-term observations from multiple satellites in combination with statistical methods. The product currently covers a period of 17 years and, with the approximation of XCO2 concentrations, represents a first step towards a further, alternative solution for studying CO2 effects for the above-mentioned research areas. Our intention is not to show regional maps of XCO2 concentrations, but for selected locations. We validate the performance of the new XCO2SAT+ method with data from the Total Carbon Column Observing Network (TCCON, Wunch et al., 2011) and compare it with XCO2 concentrations derived via the SECM and CAMS-GCM methods. Finally, we compare the results of the SECM, CAMS-GCM and XCO2SAT+ methods using CO2 concentrations measured at various heights on towers of the Integrated Carbon Observation System (ICOS ERIC, 2021) in Germany. Results: The mean average error (MAE) between the XCO2SAT+ method and TCCON site Karlsruhe, Germany ranges between 0.9 and 1.2 ppm (0.2 - 0.3%) for years 2010-2019, except for 2012 and 2014. Mean differences between XCO2SAT+ and XCO2 approximation method CAMS-GCM shows a slightly better MAE of 0.2 – 0.3 ppm for CAMS-GCM at two German TCCON sites. Multi-year comparisons with ground-level ICOS measurements revealed a comparable seasonality of CO2 concentrations during the vegetation period, but underestimated high winter concentrations, a pattern also observed when comparing with CAMS-GCM. XCO2SAT+ is a suitable alternative and simple method for providing long-term time series of monthly averaged XCO2 concentrations for selected sites, expanding the methodological toolbox for in-situ CO2 research. The new method, which so far provides XCO2 concentrations, will thus serve as a first step towards providing further CO2 data sources, which could be used to further improve numerical models such as atmospheric models or crop growth models and to study CO2 impacts in agriculture and natural ecosystems. Dataset: The dataset includes research result data (XCO2 concentrations (ppm)) derived by the XCO2SAT+ method for years 2003 - 2019 and 7 locations in Germany (2 TCCON sites and 5 ICOS sites).
Steps to reproduce
Our XCO2 approximation method method consists of three components: 1) satellite data, 2) extended segment approach using satellite data of an increasingly wider area around the target location and 3) interpolation algorithm "Spline" which are used in this sequences using quality filters to move from component 1 to 2 and 3. This dataset is associated with a scientific paper that describes the XCO2SAT+ method in detail.