REddyProc – Post-Processing of (Half-)Hourly Eddy Covariance Measurements

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F86652079%3A_____%2F18%3A00499627" target="_blank" >RIV/86652079:_____/18:00499627 - isvavai.cz</a>

Výsledek na webu

<a href="https://github.com/bgctw/REddyProc" target="_blank" >https://github.com/bgctw/REddyProc</a>

DOI - Digital Object Identifier

—

Jazyk výsledku

angličtina

Název v původním jazyce

REddyProc – Post-Processing of (Half-)Hourly Eddy Covariance Measurements

Popis výsledku v původním jazyce

With the eddy covariance (EC) technique, net fluxes of carbon dioxide (CO2) and other trace gases as well as water and energy fluxes can be measured at the ecosystem level. These flux measurements are a main source for understanding biosphere–atmosphere interactions and feedbacks through cross-site analysis, model–data integration, and upscaling. The raw fluxes measured with the EC technique require extensive and laborious data processing. While there are standard tools1 available in an open-source environment for processing high-frequency (10 or 20Hz) data into half-hourly quality-checked fluxes, there is a need for more usable and extensible tools for the subsequent post-processing steps. We tackled this need by developing the REddyProc package in the cross-platform language R that provides standard CO2-focused post-processing routines for reading (half-)hourly data from different formats, estimating the u* threshold, as well as gap-filling, flux-partitioning, and visualizing the results. In addition to basic processing, the functions are extensible and allow easier integration in extended analysis than current tools. New features include cross-year processing and a better treatment of uncertainties. A comparison of REddyProc routines with other state-of-the-art tools resulted in no significant differences in monthly and annual fluxes across sites. Lower uncertainty estimates of both u* and resulting gap-filled fluxes by 50% with the presented tool were achieved by an improved treatment of seasons during the bootstrap analysis. Higher estimates of uncertainty in daytime partitioning (about twice as high) resulted from a better accounting for the uncertainty in estimates of temperature sensitivity of respiration. The provided routines can be easily installed, configured, and used. Hence, the eddy covariance community will benefit from the REddyProc package, allowing easier integration of standard post-processing with extended analysis.

Název v anglickém jazyce

REddyProc – Post-Processing of (Half-)Hourly Eddy Covariance Measurements

Popis výsledku anglicky

With the eddy covariance (EC) technique, net fluxes of carbon dioxide (CO2) and other trace gases as well as water and energy fluxes can be measured at the ecosystem level. These flux measurements are a main source for understanding biosphere–atmosphere interactions and feedbacks through cross-site analysis, model–data integration, and upscaling. The raw fluxes measured with the EC technique require extensive and laborious data processing. While there are standard tools1 available in an open-source environment for processing high-frequency (10 or 20Hz) data into half-hourly quality-checked fluxes, there is a need for more usable and extensible tools for the subsequent post-processing steps. We tackled this need by developing the REddyProc package in the cross-platform language R that provides standard CO2-focused post-processing routines for reading (half-)hourly data from different formats, estimating the u* threshold, as well as gap-filling, flux-partitioning, and visualizing the results. In addition to basic processing, the functions are extensible and allow easier integration in extended analysis than current tools. New features include cross-year processing and a better treatment of uncertainties. A comparison of REddyProc routines with other state-of-the-art tools resulted in no significant differences in monthly and annual fluxes across sites. Lower uncertainty estimates of both u* and resulting gap-filled fluxes by 50% with the presented tool were achieved by an improved treatment of seasons during the bootstrap analysis. Higher estimates of uncertainty in daytime partitioning (about twice as high) resulted from a better accounting for the uncertainty in estimates of temperature sensitivity of respiration. The provided routines can be easily installed, configured, and used. Hence, the eddy covariance community will benefit from the REddyProc package, allowing easier integration of standard post-processing with extended analysis.

Druh

R - Software

CEP obor

—

OECD FORD obor

10509 - Meteorology and atmospheric sciences

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Interní identifikační kód produktu

REddyProc 1.1.6

Technické parametry

Eddy kovariance (EC) je mikrometeorologická technika, která umožňuje kontinuální kvantifikaci výměnu látek a energie mezi ekosystémem a atmosférou. Taková měření jsou důležitá pro pochopení ekofyziologických procesů a jejich dynamiky a tím i zobecnění výsledků v širším prostorovém měřítku. Tento balíček načítá data produkovaná softwarem, který převádí vysokofrekvenční měření na (půl)hodinové produkty a umožňuje jejich další zpracování. Zde implementované standardní a rozšiřitelné schéma zpracování eddy kovariančních dat (blíže popsáno ve Wutzler et al., 2018, doi:10.5194/bg-15-5015-2018) zahrnuje ustar filtrování, doplňování dat a separaci toků. Software podléhá licenci GPL >= 2 (Všeobecná veřejná licence GNU, verze 2 a vyšší).

Ekonomické parametry

Zpracování eddy kovariančních dat je časově náročné a vyžaduje expertní mezioborové znalosti. Formalizace výpočetních úkonů v podobě softwaru výrazně šetří čas potřebný ke zpracování dat a přináší tak úsporu v oblasti lidských zdrojů.

IČO vlastníka výsledku

86652079

Název vlastníka

Ústav výzkumu globální změny AV ČR, v. v. i.