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A high‐resolution approach to estimating ecosystem respiration at continental scales using operational satellite data
Author(s) -
Jägermeyr Jonas,
Gerten Dieter,
Lucht Wolfgang,
Hostert Patrick,
Migliavacca Mirco,
Nemani Ramakrishna
Publication year - 2014
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/gcb.12443
Subject(s) - fluxnet , biome , environmental science , moderate resolution imaging spectroradiometer , primary production , ecosystem respiration , atmospheric sciences , vegetation (pathology) , satellite , carbon cycle , enhanced vegetation index , terrestrial ecosystem , climatology , latitude , temporal resolution , ecosystem , international satellite cloud climatology project , leaf area index , normalized difference vegetation index , eddy covariance , cloud cover , ecology , geography , vegetation index , geology , physics , computer science , pathology , biology , geodesy , medicine , cloud computing , operating system , quantum mechanics , astronomy
Abstract A better understanding of the local variability in land‐atmosphere carbon fluxes is crucial to improving the accuracy of global carbon budgets. Operational satellite data backed by ground measurements at Fluxnet sites proved valuable in monitoring local variability of gross primary production at highly resolved spatio‐temporal resolutions. Yet, we lack similar operational estimates of ecosystem respiration (Re) to calculate net carbon fluxes. If successful, carbon fluxes from such a remote sensing approach would form an independent and sought after measure to complement widely used dynamic global vegetation models ( DGVM s). Here, we establish an operational semi‐empirical Re model, based only on data from the Moderate Resolution Imaging Spectroradiometer ( MODIS ) with a resolution of 1 km and 8 days. Fluxnet measurements between 2000 and 2009 from 100 sites across North America and Europe are used for parameterization and validation. Our analysis shows that Re is closely tied to temperature and plant productivity. By separating temporal and intersite variation, we find that MODIS land surface temperature ( LST ) and enhanced vegetation index ( EVI ) are sufficient to explain observed Re across most major biomes with a negligible bias [ R ² = 0.62, RMSE = 1.32 (g C m −2 d −1 ), MBE = 0.05 (g C m −2 d −1 )]. A comparison of such satellite‐derived Re with those simulated by the DGVM LPJ mL reveals similar spatial patterns. However, LPJ mL shows higher temperature sensitivities and consistently simulates higher Re values, in high‐latitude and subtropical regions. These differences remain difficult to explain and they are likely associated either with LPJ mL parameterization or with systematic errors in the Fluxnet sampling technique. While uncertainties remain with Re estimates, the model formulated in this study provides an operational, cross‐validated and unbiased approach to scale Fluxnet Re to the continental scale and advances knowledge of spatio‐temporal Re variability.