Matches in SemOpenAlex for { <https://semopenalex.org/work/W4322009984> ?p ?o ?g. }
Showing items 1 to 56 of
56
with 100 items per page.
- W4322009984 abstract "Eddy covariance techniques are widely used to measure the net exchange of greenhouse between the surface and the atmosphere, providing high resolution, instantaneous flux measures and long-term observations, which in turn allows more accurate assessments of the ecosystem’s state. However, gaps in eddy covariance time series reduce the statistical efficiency and increase bias estimates, hampering predictions of ecosystem function. Although, several imputation techniques have been proposed to overcome these difficulties, including Marginal Distribution Sampling (MDS), the standard method of FLUXNET, MDS has limitations for filling long gaps (weeks to months). In this study, we combine MDS and machine learning imputation techniques to fill an 18-year time series of carbon fluxes. Our objective was to evaluate whether Random Forest algorithms are able to fill long-gaps and detect seasonality, as well as to identify the best predictors of ecosystem exchange, gross primary productivity, and ecosystem respiration. The eddy covariance raw-data were obtained from an experiment in an upland semi-natural grassland in the Auvergne region of France that has been managed by continuous cattle grazing under low animal stocking rate.  After raw-data processing using EddyPro software, we applied the MDS technique to half-hour data to fill the short-gaps, and then used a Random Forest (RF) algorithm to daily data to fill longer gaps. The time series was split into a training and testing dataset, and all variables describing atmospheric conditions, solar radiation, and energy fluxes were used to predict C fluxes. Random Forest models with high R2 and low prediction error increases were used to impute the long-gaps.  The cross-validation between observed and predicted values in the test dataset obtained R2 of greater than 0.85 for all carbon flux variables. Our analysis also revealed that the daily carbon flux values could be estimated using the basic meteorological variables, i.e., air temperature, precipitation, atmospheric pression, friction velocity, and wind speed, but also by energy fluxes. Finally, the imputed dataset presented similar seasonality along the years, with the highest C sequestration and respiration in the summer and spring. These results highlight the value of machine learning techniques for producing robust, long-term eddy flux data time series." @default.
- W4322009984 created "2023-02-26" @default.
- W4322009984 creator A5024468539 @default.
- W4322009984 creator A5028549151 @default.
- W4322009984 creator A5030750651 @default.
- W4322009984 date "2023-05-15" @default.
- W4322009984 modified "2023-09-27" @default.
- W4322009984 title "Random forest algorithm for long-gap imputation in Eddy Covariance data: a case study in an upland semi-natural grassland in the Auvergne region" @default.
- W4322009984 doi "https://doi.org/10.5194/egusphere-egu23-8031" @default.
- W4322009984 hasPublicationYear "2023" @default.
- W4322009984 type Work @default.
- W4322009984 citedByCount "0" @default.
- W4322009984 crossrefType "posted-content" @default.
- W4322009984 hasAuthorship W4322009984A5024468539 @default.
- W4322009984 hasAuthorship W4322009984A5028549151 @default.
- W4322009984 hasAuthorship W4322009984A5030750651 @default.
- W4322009984 hasConcept C105795698 @default.
- W4322009984 hasConcept C110872660 @default.
- W4322009984 hasConcept C11413529 @default.
- W4322009984 hasConcept C178650346 @default.
- W4322009984 hasConcept C18903297 @default.
- W4322009984 hasConcept C2780207091 @default.
- W4322009984 hasConcept C33923547 @default.
- W4322009984 hasConcept C35187779 @default.
- W4322009984 hasConcept C39432304 @default.
- W4322009984 hasConcept C58041806 @default.
- W4322009984 hasConcept C86803240 @default.
- W4322009984 hasConcept C9357733 @default.
- W4322009984 hasConceptScore W4322009984C105795698 @default.
- W4322009984 hasConceptScore W4322009984C110872660 @default.
- W4322009984 hasConceptScore W4322009984C11413529 @default.
- W4322009984 hasConceptScore W4322009984C178650346 @default.
- W4322009984 hasConceptScore W4322009984C18903297 @default.
- W4322009984 hasConceptScore W4322009984C2780207091 @default.
- W4322009984 hasConceptScore W4322009984C33923547 @default.
- W4322009984 hasConceptScore W4322009984C35187779 @default.
- W4322009984 hasConceptScore W4322009984C39432304 @default.
- W4322009984 hasConceptScore W4322009984C58041806 @default.
- W4322009984 hasConceptScore W4322009984C86803240 @default.
- W4322009984 hasConceptScore W4322009984C9357733 @default.
- W4322009984 hasLocation W43220099841 @default.
- W4322009984 hasOpenAccess W4322009984 @default.
- W4322009984 hasPrimaryLocation W43220099841 @default.
- W4322009984 hasRelatedWork W2039088678 @default.
- W4322009984 hasRelatedWork W2122471420 @default.
- W4322009984 hasRelatedWork W2291727072 @default.
- W4322009984 hasRelatedWork W2363155382 @default.
- W4322009984 hasRelatedWork W2757806320 @default.
- W4322009984 hasRelatedWork W3040243316 @default.
- W4322009984 hasRelatedWork W3195878144 @default.
- W4322009984 hasRelatedWork W4200418898 @default.
- W4322009984 hasRelatedWork W4234736829 @default.
- W4322009984 hasRelatedWork W4377043666 @default.
- W4322009984 isParatext "false" @default.
- W4322009984 isRetracted "false" @default.
- W4322009984 workType "article" @default.