Limitations and improvements of the energy balance closure with reference to experimental data measured over a maize field
Articolo
Data di Pubblicazione:
2014
Citazione:
Limitations and improvements of the energy balance closure with reference to experimental data measured over a maize field / D. Masseroni, C. Corbari, M. Mancini. - In: ATMOSFERA. - ISSN 0187-6236. - 27:4(2014 Jun), pp. 335-352. [10.1016/S0187-6236(14)70033-5]
Abstract:
The use of energy fluxes data to validate land surface models requires that energy balance closure conservation is satisfied, but usually this condition is not verified when the available energy is bigger than the sum
of turbulent vertical fluxes. In this work, a comprehensive evaluation of energy balance closure problems is
performed on a 2012 data set from Livraga obtained by a micrometeorological eddy covariance station located
in a maize field in the Po Valley. Energy balance closure is calculated by statistical regression of turbulent
energy fluxes and soil heat flux against available energy. Generally, the results indicate a lack of closure with
a mean imbalance in the order of 20%. Storage terms are the main reason for the unclosed energy balance but
also the turbulent mixing conditions play a fundamental role in reliable turbulent flux estimations. Recently
introduced in literature, the energy balance problem has been studied as a scale problem. A representative
source area for each flux of the energy balance has been analyzed and the closure has been performed in
function of turbulent flux footprint areas. Surface heterogeneity and seasonality effects have been studied to 336
understand the influence of canopy growth on the energy balance closure. High frequency data have been
used to calculate co-spectral and ogive functions, which suggest that an averaging period of 30 min may miss
temporal scales that contribute to the turbulent fluxes. Finally, latent and sensible heat random error estimations are computed to give information about the measurement system and turbulence transport deficiencies.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
D. Masseroni, C. Corbari, M. Mancini
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