Observation of the winter regional evaporative fraction using a UAV-based eddy covariance system over wetland area

2021 ◽  
Vol 310 ◽  
pp. 108619
Author(s):  
Yibo Sun ◽  
Bilige Sude ◽  
Bing Geng ◽  
Junyong Ma ◽  
Xingwen Lin ◽  
...  
Keyword(s):  
Eddy Covariance ◽  
Wetland Area ◽  
Evaporative Fraction ◽  
Eddy Covariance System

scholarly journals Energy balance measurements over a banana orchard in the Semiarid region in the Northeast of Brazil

2009 ◽  
Vol 44 (11) ◽  
pp. 1365-1373 ◽  
Author(s):  
Carlos Antonio Costa dos Santos ◽  
Bernardo Barbosa da Silva ◽  
Tantravahi Venkata Ramana Rao ◽  
Christopher Michael Usher Neale
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Eddy Covariance ◽  
Heat Fluxes ◽  
Irrigation District ◽  
Semiarid Region ◽  
Energy Balance Closure ◽  
Wet Season ◽  
Growing Seasons ◽  
Eddy Covariance System

The objective of this work was to evaluate the reliability of eddy covariance measurements, analyzing the energy balance components, evapotranspiration and energy balance closure in dry and wet growing seasons, in a banana orchard. The experiment was carried out at a farm located within the irrigation district of Quixeré, in the Lower Jaguaribe basin, in Ceará state, Brazil. An eddy covariance system was used to measure the turbulent flux. An automatic weather station was installed in a grass field to obtain the reference evapotranspiration (ET0) from the combined FAO-Penman-Monteith method. Wind speed and vapor pressure deficit are the most important variables on the evaporative process in both growing seasons. In the dry season, the heat fluxes have a similar order of magnitude, and during the wet season the latent heat flux is the largest. The eddy covariance system had acceptable reliability in measuring heat flux, with actual evapotranspiration results comparing well with those obtained by using the water balance method. The energy balance closure had good results for the study area, with mean values of 0.93 and 0.86 for the dry and wet growing seasons respectively.

scholarly journals Emissions of carbon dioxide and methane from fields fertilized with digestate from an agricultural biogas plant

2018 ◽  
Vol 32 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Robert Czubaszek ◽  
Agnieszka Wysocka-Czubaszek
Keyword(s):  
Carbon Dioxide ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Eddy Covariance ◽  
Soil Structure ◽  
Mineral Fertilizers ◽  
Gas Emissions ◽  
Gas Fluxes ◽  
Biogas Plants ◽  
Eddy Covariance System

AbstractDigestate from biogas plants can play important role in agriculture by providing nutrients, improving soil structure and reducing the use of mineral fertilizers. Still, less is known about greenhouse gas emissions from soil during and after digestate application. The aim of the study was to estimate the emissions of carbon dioxide (CO2) and methane (CH4) from a field which was fertilized with digestate. The gas fluxes were measured with the eddy covariance system. Each day, the eddy covariance system was installed in various places of the field, depending on the dominant wind direction, so that each time the results were obtained from an area where the digestate was distributed. The results showed the relatively low impact of the studied gases emissions on total greenhouse gas emissions from agriculture. Maximum values of the CO2and CH4fluxes, 79.62 and 3.049 µmol s−1m−2, respectively, were observed during digestate spreading on the surface of the field. On the same day, the digestate was mixed with the topsoil layer using a disc harrow. This resulted in increased CO2emissions the following day. Intense mineralization of digestate, observed after fertilization may not give the expected effects in terms of protection and enrichment of soil organic matter.

Vineyard evaporative fraction based on eddy covariance in an arid desert region of Northwest China

2008 ◽  
Vol 95 (8) ◽  
pp. 937-948 ◽  
Author(s):  
Sien Li ◽  
Shaozhong Kang ◽  
Fusheng Li ◽  
Lu Zhang ◽  
Baozhong Zhang
Keyword(s):  
Eddy Covariance ◽  
Northwest China ◽  
Evaporative Fraction ◽  
Desert Region ◽  
Arid Desert

Surface energy flux measurements in a flooded and an aerobic rice field using a single eddy-covariance system

2014 ◽  
Vol 13 (4) ◽  
pp. 405-424 ◽  
Author(s):  
Daniele Masseroni ◽  
Arianna Facchi ◽  
Marco Romani ◽  
Enrico Antonio Chiaradia ◽  
Olfa Gharsallah ◽  
...  
Keyword(s):  
Surface Energy ◽  
Eddy Covariance ◽  
Energy Flux ◽  
Rice Field ◽  
Aerobic Rice ◽  
Surface Energy Flux ◽  
Flux Measurements ◽  
Eddy Covariance System

scholarly journals Design of the AmeriFlux Portable Eddy Covariance System and Uncertainty Analysis of Carbon Measurements

2007 ◽  
Vol 24 (8) ◽  
pp. 1389-1406 ◽  
Author(s):  
T. W. Ocheltree ◽  
H. W. Loescher
Keyword(s):  
Eddy Covariance ◽  
Spatial Scales ◽  
Flux Measurement ◽  
Field Measurements ◽  
Quality Control Laboratory ◽  
Flux Measurements ◽  
Eddy Covariance System ◽  
Uncertainty Analyses ◽  
Infrared Gas Analyzer ◽  
Ambient Co2

Abstract The AmeriFlux network continues to improve the understanding of carbon, water, and energy fluxes across temporal and spatial scales. The network includes ∼120 research sites that contribute to the understanding of processes within and among ecosystems. To improve the networks ability and confidence to synthesize data across multiple sites, the AmeriFlux quality assurance and quality control laboratory was established to reduce the within- and among-site uncertainties. This paper outlines the design of the portable eddy covariance system (PECS) and subsequent data processing procedures used for site comparisons. Because the PECS makes precision measurements of atmospheric CO2, the authors also present the results of uncertainty analyses in determining the polynomials for an infrared gas analyzer, estimating the CO2 in secondary standards, and estimating ambient CO2 in field measurements. Under field conditions, drift in the measurement of CO2 increased the uncertainty in flux measurements across 7 days by 5% and was not dependent on the magnitude or direction of the flux. The maximum relative flux measurement error for unstable conditions was 10.03 μmol CO2 m−2 s−1.

scholarly journals Aplicação do produto de evapotranspiração do MODIS para uma área de pastagem na Amazônia ocidental

2018 ◽  
Vol 40 ◽  
pp. 162
Author(s):  
Agni Cristina de Carvalho Brito ◽  
Nara Luisa Reis de Andrade ◽  
Larissa Santos Fambri ◽  
Camila Bermond Ruezzene ◽  
Renata Gonçalves Aguiar
Keyword(s):  
Land Use ◽  
Quality Control ◽  
Eddy Covariance ◽  
Linear Correlation ◽  
Seasonal Variations ◽  
Natural Ecosystems ◽  
Data Set ◽  
Water Cycling ◽  
Eddy Covariance System ◽  
Pasture Area

The processes of land use and occupation generate interventions in the natural ecosystems making them susceptible to reactions, such as changes in the processes that govern water cycling, emphasizing the importance of monitoring the evapotranspiration behavior. In this sense, the objective of this study was to verify the applicability of the evaporation product originated by the MODIS sensor to a pasture area, from 2003 to 2010, at Fazenda Nossa Senhora in the municipality of Ouro Preto do Oeste - Rondônia. Were used evapotranspiration data from the MODIS (Terra / Aqua) sensor, estimated by MOD16 algorithm, and micrometeorological tower located in the pasture area, generated by eddy covariance system. It was verified that for ET Eddy x ET MOD16 (Quality control – QC 0/8) data set, ET MOD16 (QC 0/8) data showed evapotranspiration values above those of ET Eddy and with a greater amplitude. A linear correlation between the study datasets was not identified, however, seasonal variations are captured by product, showing good approximation with ET Eddy data, especially in the transition periods.

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