| Contributors: |
Nelson, Jacob A.; Walther, Sophia; Gans, Fabian; Kraft, Basil; Weber, Ulrich; Novick, Kimberly; Buchmann, Nina; Migliavacca, Mirco; Wohlfahrt, Georg; Šigut, Ladislav; Ibrom, Andrea; Papale, Dario; Göckede, Mathia; Duveiller, Gregory; Knohl, Alexander; Hörtnagl, Luka; Scott, Russell L.; Zhang, Weijie; Mahmoud Hamdi, Zayd; Reichstein, Marku; Aranda-Barranco, Sergio; Ardö, Jona; Op de Beeck, Maarten; Billesbach, Dave; Bowling, David; Bracho, Rosvel; Brümmer, Christian; Camps-Valls, Gustau; Chen, Shiping; Rose Cleverly, Jamie; Desai, Ankur; Dong, Gang; El-Madany, Tarek S.; Susanne Euskirchen, Eugenie; Feigenwinter, Iri; Galvagno, Marta; Gerosa, Giacomo A.; Gielen, Bert; Goded, Ignacio; Goslee, Sarah; Michael Gough, Christopher; Heinesch, Bernard; Ichii, Kazuhito; Antoni Jackowicz-Korczynski, Marcin; Klosterhalfen, Anne; Knox, Sara; Kobayashi, Hideki; Kohonen, Kukka-Maaria; Korkiakoski, Mika; Mammarella, Ivan; Gharun, Mana; Marzuoli, Riccardo; Matamala, Roser; Metzger, Stefan; Montagnani, Leonardo; Nicolini, Giacomo; O’Halloran, Thoma; Ourcival, Jean-Marc; Peichl, Matthia; Pendall, Elise; Ruiz Reverter, Borja; Roland, Marilyn; Sabbatini, Simone; Sachs, Torsten; Schmidt, Mariu; Schwalm, Christopher R.; Shekhar, Ankit; Silberstein, Richard; Lucia Silveira, Maria; Spano, Donatella; Tagesson, Torbern; Tramontana, Gianluca; Trotta, Carlo; Turco, Fabio; Vesala, Timo; Vincke, Caroline; Vitale, Domenico; Vivoni, Enrique R.; Wang, Yi; Woodgate, William; Yepez, Enrico A.; Zhang, Junhui; Zona, Donatella; Martin Jung, And |
| Description: |
Mapping in situ eddy covariance measurements of terrestrial land–atmosphere fluxes to the globe is a key method for diagnosing the Earth system from a data-driven perspective. We describe the first global products (called X-BASE) from a newly implemented upscaling framework, FLUXCOM-X, representing an advancement from the previ- ous generation of FLUXCOM products in terms of flexibility and technical capabilities. The X-BASE products are com- prised of estimates of CO2 net ecosystem exchange (NEE), gross primary productivity (GPP), evapotranspiration (ET), and for the first time a novel, fully data-driven global transpiration product (ETT), at high spatial (0.05°) and temporal (hourly) resolution. X-BASE estimates the global NEE at −5.75 ± 0.33 Pg C yr−1 for the period 2001–2020, showing a much higher consistency with independent atmospheric carbon cycle constraints compared to the previous versions of FLUXCOM. The improvement of global NEE was likely only possible thanks to the international effort to increase the precision and consistency of eddy covariance collection and processing pipelines, as well as to the extension of the measurements to more site years resulting in a wider coverage of bioclimatic conditions. However, X-BASE global net ecosystem exchange shows a very low interannual variability, which is common to state-of-the-art data-driven flux products and remains a scientific challenge. With 125 ± 2.1 Pg C yr−1 for the same period, X-BASE GPP is slightly higher than pre- vious FLUXCOM estimates, mostly in temperate and bo- real areas. X-BASE evapotranspiration amounts to 74.7× 103 ± 0.9×103 km3 globally for the years 2001–2020 but ex- ceeds precipitation in many dry areas, likely indicating over- estimation in these regions. On average 57 % of evapotranspiration is estimated to be transpiration, in good agreement with isotope-based approaches, but higher than estimates from many land surface models. Despite considerable improvements to the previous upscaling products, many further opportunities for ... |