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

Role of SAR in Surface Energy Flux Measurements Over Sea Ice

1998 ◽  
pp. 35-67 ◽  
Author(s):  
D. G. Barber ◽  
A. Thomas ◽  
T. N. Papakyriakou
Keyword(s):  
Surface Energy ◽  
Sea Ice ◽  
Energy Flux ◽  
Surface Energy Flux ◽  
Flux Measurements

Different energetics of global monsoon over land and ocean

2021 ◽  
Author(s):  
Arindam Chakraborty ◽  
Chetankumar Jalihal ◽  
Jayaraman Srinivasan
Keyword(s):  
Surface Energy ◽  
Energy Flux ◽  
Global Climate ◽  
Lower Troposphere ◽  
Summer Precipitation ◽  
Reanalysis Data ◽  
Vertical Transport ◽  
Net Energy ◽  
Global Monsoon ◽  
Surface Energy Flux

<p>Monsoons were traditionally considered to be land-based systems. Recent definitions of monsoons based on either the seasonal reversal of winds or the local summer precipitation accounting for more than 50% of the annual precipitation suggests that monsoon domains extend over oceanic regions as well. The concept of global monsoon combines all the monsoon domains into a single entity. Modern observations show that the variations in precipitation are nearly coherent across all the individual monsoon domains on decadal timescales. Using a transient simulation of the global climate over the last 22,000 years as well as reanalysis data of the modern climate, we have shown that tropical precipitation has different characteristics over land and ocean grids. This is due to the differences in the energetics of monsoon over land and ocean grids. With a lower thermal heat capacity, the net surface energy flux over land is negligible, whereas it is quite large over the ocean. In fact, the orbital scale variability of net energy flux into the atmosphere over the ocean is controlled by the surface energy flux. Another major difference between land and ocean grids of the global monsoon is in the vertical profile of the vertical pressure velocity. It is bottom-heavy over land and top-heavy over the ocean. This results in smaller vertical transport of moist static energy (which has a minimum in the lower troposphere) over land, and a larger vertical transport over the ocean. These differences between the land and ocean, suggest that the land and ocean grids should not be combined as is traditionally done. Global monsoon-land and global monsoon-ocean should be studied separately.</p>

scholarly journals Evaluation of satellite and reanalysis-based global net surface energy flux and uncertainty estimates

2017 ◽  
Vol 122 (12) ◽  
pp. 6250-6272 ◽  
Author(s):  
Chunlei Liu ◽  
Richard P. Allan ◽  
Michael Mayer ◽  
Patrick Hyder ◽  
Norman G. Loeb ◽  
...  
Keyword(s):  
Surface Energy ◽  
Energy Flux ◽  
Surface Energy Flux ◽  
Uncertainty Estimates

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.

Optical properties and surface energy flux of spring fast ice in the Arctic

2021 ◽  
Vol 40 (10) ◽  
pp. 84-96
Author(s):  
Jialiang Zhu ◽  
Yilin Liu ◽  
Xiaoyu Wang ◽  
Tao Li
Keyword(s):  
Optical Properties ◽  
Surface Energy ◽  
Energy Flux ◽  
The Arctic ◽  
Surface Energy Flux ◽  
Fast Ice

A Comparative Study on Surface Energy Flux Characteristics of Photovoltaic Power Station in Gobi in Summer

2021 ◽  
Author(s):  
Zhenchao Li ◽  
Yanyan Zhao ◽  
Jiaxi Yang ◽  
Yong Luo ◽  
Ye Yu ◽  
...  
Keyword(s):  
Surface Energy ◽  
Comparative Study ◽  
Energy Flux ◽  
Power Station ◽  
Surface Energy Flux ◽  
Photovoltaic Power

Long-term energy flux measurements and energy balance over a small boreal lake using eddy covariance technique

2011 ◽  
Vol 116 (D2) ◽  
Author(s):  
Annika Nordbo ◽  
Samuli Launiainen ◽  
Ivan Mammarella ◽  
Matti Leppäranta ◽  
Jussi Huotari ◽  
...  
Keyword(s):  
Energy Balance ◽  
Eddy Covariance ◽  
Energy Flux ◽  
Eddy Covariance Technique ◽  
Boreal Lake ◽  
Flux Measurements ◽  
Term Energy

First application of low-cost eddy covariance for CO2 fluxes over agroforestry

2020 ◽  
Author(s):  
Justus van Ramshorst ◽  
Christian Markwitz ◽  
Timothy Hill ◽  
Robert Clement ◽  
Alexander Knohl ◽  
...  
Keyword(s):  
Eddy Covariance ◽  
Low Cost ◽  
Net Ecosystem Exchange ◽  
Agroforestry Systems ◽  
Agricultural System ◽  
Data Series ◽  
Custom Made ◽  
Flux Measurements ◽  
Eddy Covariance System ◽  
The Difference

<p>Agroforestry is a combination of monoculture agriculture and trees. Studies of net ecosystem exchange of CO<sub>2</sub> (NEE) of agroforestry systems are rare, in comparison to the extensive studies of NEE of agricultural systems (croplands and grasslands). Agroforestry has been shown to alter the microclimate, productivity, and nutrient and water usage – as compared to standard agricultural practise. The, potentially, higher carbon sequestration of agroforestry, relative to monoculture systems, provides an interesting option for mitigating climate change, highlighting the need for improved study of agroforestry systems. The current study, as part of the SIGNAL (sustainable intensification of agriculture through agroforestry) project, investigates NEE of agroforestry compared to that of monoculture agriculture. The study employs paired comparisons of flux measurements above agroforestry and monoculture agronomy, replicated at five locations across Germany. Fluxes are measured, using innovative low-cost CO<sub>2</sub> eddy covariance sensors (slow response Vaisala GMP343 IRGA with custom made housing), which have been successfully used in a study over grassland. Continuous data series from mid-summer until winter 2019 show that both systems acted as a sink with comparable fluxes during summer. The diurnal CO<sub>2</sub> cycle and the response to management activities are distinguishable and in autumn preliminary results suggest a small difference in fluxes between the two systems. The low-cost eddy covariance system is able to capture the turbulence and to measure the CO<sub>2</sub> flux over the agroforestry and monoculture agricultural system. We aim to further improve the quality of the CO<sub>2</sub> fluxes, by adapting post-processing software to better estimate the difference in carbon uptake between the agroforestry and monoculture systems.</p>

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