Details
| Original language | English |
|---|---|
| Article number | 110211 |
| Number of pages | 29 |
| Journal | Agricultural and Forest Meteorology |
| Volume | 358 |
| Early online date | 7 Sept 2024 |
| Publication status | Published - 15 Nov 2024 |
Abstract
The non-closure of surface energy balance, often encountered in eddy covariance (EC) measurements, raises a critical query: does this non-closure lead to underestimated scalar fluxes, particularly CO2 flux (Fc), when using the same theoretical framework in EC? To address this question, we utilize high-resolution large-eddy simulations (LESs) to explore correlations between energy flux imbalances and Fc imbalances in convective boundary layers, considering both homogeneous and idealized heterogeneous surfaces. Our findings reveal that the unsteady CO2 or storage represents a leading factor influencing Fc imbalance, especially notable when the entrainment ratio for Fc is large. Even in scenarios with uniform surface Fcs, heterogeneous thermally-generated turbulence resulting from variable surface sensible heat flux (H) can induce substantial horizontal flux divergence, magnifying Fc imbalance. While a linear correlation between the energy flux imbalance and Fc imbalance arises under shared causative mechanisms (e.g., storage), complex correlations emerge if their influencing factors differ, contingent upon surface heterogeneity and site location. This complexity underscores the limitations in applying the closing methods for energy flux imbalance to the Fc imbalance.
Keywords
- CO flux, Convective boundary layer, Energy balance nonclosure, Flux imbalance, Large eddy simulation, Surface heterogeneity
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)
- Forestry
- Environmental Science(all)
- Global and Planetary Change
- Agricultural and Biological Sciences(all)
- Agronomy and Crop Science
- Earth and Planetary Sciences(all)
- Atmospheric Science
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In: Agricultural and Forest Meteorology, Vol. 358, 110211, 15.11.2024.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Implications of energy balance non-closure on carbon dioxide flux uncertainties
T2 - Insights from large eddy simulations in convective boundary layers
AU - Zhou, Yanzhao
AU - Liu, Heping
AU - Sühring, Matthias
AU - Li, Xin
N1 - Publisher Copyright: © 2024 The Author(s)
PY - 2024/11/15
Y1 - 2024/11/15
N2 - The non-closure of surface energy balance, often encountered in eddy covariance (EC) measurements, raises a critical query: does this non-closure lead to underestimated scalar fluxes, particularly CO2 flux (Fc), when using the same theoretical framework in EC? To address this question, we utilize high-resolution large-eddy simulations (LESs) to explore correlations between energy flux imbalances and Fc imbalances in convective boundary layers, considering both homogeneous and idealized heterogeneous surfaces. Our findings reveal that the unsteady CO2 or storage represents a leading factor influencing Fc imbalance, especially notable when the entrainment ratio for Fc is large. Even in scenarios with uniform surface Fcs, heterogeneous thermally-generated turbulence resulting from variable surface sensible heat flux (H) can induce substantial horizontal flux divergence, magnifying Fc imbalance. While a linear correlation between the energy flux imbalance and Fc imbalance arises under shared causative mechanisms (e.g., storage), complex correlations emerge if their influencing factors differ, contingent upon surface heterogeneity and site location. This complexity underscores the limitations in applying the closing methods for energy flux imbalance to the Fc imbalance.
AB - The non-closure of surface energy balance, often encountered in eddy covariance (EC) measurements, raises a critical query: does this non-closure lead to underestimated scalar fluxes, particularly CO2 flux (Fc), when using the same theoretical framework in EC? To address this question, we utilize high-resolution large-eddy simulations (LESs) to explore correlations between energy flux imbalances and Fc imbalances in convective boundary layers, considering both homogeneous and idealized heterogeneous surfaces. Our findings reveal that the unsteady CO2 or storage represents a leading factor influencing Fc imbalance, especially notable when the entrainment ratio for Fc is large. Even in scenarios with uniform surface Fcs, heterogeneous thermally-generated turbulence resulting from variable surface sensible heat flux (H) can induce substantial horizontal flux divergence, magnifying Fc imbalance. While a linear correlation between the energy flux imbalance and Fc imbalance arises under shared causative mechanisms (e.g., storage), complex correlations emerge if their influencing factors differ, contingent upon surface heterogeneity and site location. This complexity underscores the limitations in applying the closing methods for energy flux imbalance to the Fc imbalance.
KW - CO flux
KW - Convective boundary layer
KW - Energy balance nonclosure
KW - Flux imbalance
KW - Large eddy simulation
KW - Surface heterogeneity
UR - http://www.scopus.com/inward/record.url?scp=85203168166&partnerID=8YFLogxK
U2 - 10.1016/j.agrformet.2024.110211
DO - 10.1016/j.agrformet.2024.110211
M3 - Article
AN - SCOPUS:85203168166
VL - 358
JO - Agricultural and Forest Meteorology
JF - Agricultural and Forest Meteorology
SN - 0168-1923
M1 - 110211
ER -