Multi-year observations reveal a larger than expected autumn respiration signal across northeast Eurasia

• Main Authors: Byrne, B, Liu, J, Yi, Y, Chatterjee, A, Basu, S, Cheng, R, Doughty, R, Chevallier, F, Bowman, KW, Parazoo, NC, Crisp, D, Li, X, Xiao, J, Sitch, S, Guenet, B, Deng, F, Johnson, MS, Philip, S, McGuire, PC, Miller, CE
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus GmbH 2022
• Subjects: Arctic; Crowell; Muñoz
• Online Access: http://hdl.handle.net/10871/131638; https://doi.org/10.5194/bg-19-4779-2022

This is the final version. Available from Copernicus Publications via the DOI in this record. Data availability TRENDY v8 gridded data were accessed by contacting Stephen Sitch following the TRENDY data policy described on their website: https://sites.exeter.ac.uk/trendy (Sitch et al., 2022). v9 OCO-2 MIP fluxes were downloaded from https://gml.noaa.gov/ccgg/OCO2_v9mip/ (Crowell et al., 2022). GFED data were downloaded from https://www.globalfiredata.org/ (Randerson et al., 2022). We downloaded version 10 of the ACOS OCO-2 lite files from the GES DISC (https://doi.org/10.5067/W8QGIYNKS3JC, OCO-2 et al., 2018). OCO-2 data were produced by the OCO-2 project at the Jet Propulsion Laboratory, California Institute of Technology, and obtained from the OCO-2 data archive maintained at the NASA Goddard Earth Science Data and Information Services Center. FluxSat data were downloaded from https://avdc.gsfc.nasa.gov/pub/tmp/FluxSat_GPP/ (Joiner, 2022). The GOSIF data product (Li and Xiao, 2019) is available at http://data.globalecology.unh.edu/, (Li and Xiao, 2019). ERA5-Land data are obtained from the Climate Data Store (https://doi.org/10.24381/cds.68d2bb30, Muñoz Sabater, 2019). Abstract. Site-level observations have shown pervasive cold season CO2 release across Arctic and boreal ecosystems, impacting annual carbon budgets. Still, the seasonality of CO2 emissions are poorly quantified across much of the high latitudes due to the sparse coverage of site-level observations. Space-based observations provide the opportunity to fill some observational gaps for studying these high-latitude ecosystems, particularly across poorly sampled regions of Eurasia. Here, we show that data-driven net ecosystem exchange (NEE) from atmospheric CO2 observations implies strong summer uptake followed by strong autumn release of CO2 over the entire cold northeastern region of Eurasia during the 2015–2019 study period. Combining data-driven NEE with satellite-based estimates of gross primary production (GPP), we show that this seasonality ...