Corrigendum to “Surface energy balance of an extensive green roof as quantified by full year eddy-covariance measurements” [577 (2017) 220–230/article number]

<p>The apparent lack of surface energy balance closure is one of the most crucial challenges in the measurement of biosphere-atmosphere exchange. In principle, this issue can have a variety of potential reasons, including instrumental errors and errors introduced in the data processing chain. In addition, secondary circulations have been identified as one of the main reasons for a non-closure of the surface energy balance, since the related energy transport cannot be captured by common eddy-covariance tower flux measurements. When present, neglecting this process will result in an underestimation of turbulent fluxes. Secondary circulations can, however, be represented by means of large-eddy simulations, which have been employed to develop a novel semi-empirical model to correct for the missing large-scale flux (De Roo et al. 2018, DOI 10.1371/journal.pone.0209022). In this study, we compare the results of this process-based method with two other previously published bulk-correction methods (Mauder et al. 2013, DOI 10.1016/j.agrformet.2012.09.006; Charuchittipan et al. 2014, DOI 10.1007/s10546-014-9922-6). These three correction methods are applied for multiple sites in different biomes around the world. Independent data of energy fluxes from these sites are used to assess which of these methods leads to the most reliable results, and we discuss the limitations of these corrections methods with respect to meteorological conditions and site characteristics, such as measurement height, the landscape-scale heterogeneity and terrain complexity.</p>

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Extensive green roof CO2 exchange and its seasonal variation quantified by eddy covariance measurements

The Science of The Total Environment ◽

10.1016/j.scitotenv.2017.07.052 ◽

2017 ◽

Vol 607-608 ◽

pp. 623-632 ◽

Cited By ~ 7

Author(s):

Jannik Heusinger ◽

Stephan Weber

Keyword(s):

Seasonal Variation ◽

Eddy Covariance ◽

Green Roof ◽

Co2 Exchange ◽

Extensive Green Roof ◽

Eddy Covariance Measurements

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On the Use of the Eddy Covariance Latent Heat Flux and Sap Flow Transpiration for the Validation of a Surface Energy Balance Model

Remote Sensing ◽

10.3390/rs10020195 ◽

2018 ◽

Vol 10 (2) ◽

pp. 195 ◽

Cited By ~ 6

Author(s):

Antonino Maltese ◽

Hassan Awada ◽

Fulvio Capodici ◽

Giuseppe Ciraolo ◽

Goffredo La Loggia ◽

...

Keyword(s):

Heat Flux ◽

Energy Balance ◽

Surface Energy ◽

Eddy Covariance ◽

Latent Heat ◽

Latent Heat Flux ◽

Sap Flow ◽

Surface Energy Balance ◽

Energy Balance Model ◽

Balance Model

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Surface energy balance closure – the role dispersive fluxes induced by submesoscale secondary circulations

10.5194/egusphere-egu21-1057 ◽

2021 ◽

Author(s):

Matthias Mauder

Keyword(s):

Energy Balance ◽

Surface Energy ◽

Eddy Covariance ◽

Large Scale ◽

Surface Energy Balance ◽

Heat Fluxes ◽

Turbulent Heat ◽

Energy Balance Closure ◽

Secondary Circulations ◽

Dispersive Fluxes

<p>Quantitative knowledge of the surface energy balance is essential for the prediction of weather and climate. However, a multitude of studies from around the world indicates that the turbulent heat fluxes are generally underestimated using eddy-covariance measurements, and hence, the surface energy balance is not closed. This energy balance closure problem has been heavily covered in the literature for more than 25 years, and as a result, several instrumental and methodological aspects have been reconsidered and partially revised. Nevertheless, a non-negligible energy imbalance remains, and we demonstrate that a major portion of this imbalance can be explained by dispersive fluxes in the surface layer, which are associated with submesoscale secondary circulations. Such large-scale organized structures are a very common phenomenon in the convective boundary layer, and depending on static stability, they can either be roll-like or cell-like and occur even over homogeneous surfaces. Over heterogeneous surfaces, thermally-induced mesoscale circulations can occur in addition to those. Either way, the associated dispersive heat fluxes can inherently not be captured by single-tower measurements, since the ergodicity assumption is violated. As a consequence, energy transported non-turbulently will not be sensed by eddy-covariance systems and a bias towards lower energy fluxes will result. The objective of this research is to develop a model that can be used to correct single-tower eddy-covariance data. As a first step towards this goal, we will present a parametrisation for dispersive fluxes, which was developed based on an idealized high-resolution LES study for homogeneous surfaces, as a function of non-local scaling variables. Secondly, we explore how well this parametrisation works for a number of real-world eddy-covariance sites.</p>

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Using climate reanalysis data in conjunction with multi-temporal satellite thermal imagery to derive supraglacial debris thickness changes from energy-balance modelling

Journal of Glaciology ◽

10.1017/jog.2020.111 ◽

2021 ◽

pp. 1-19

Author(s):

Rebecca L. Stewart ◽

Matthew Westoby ◽

Francesca Pellicciotti ◽

Ann Rowan ◽

Darrel Swift ◽

...

Keyword(s):

Energy Balance ◽

Surface Energy ◽

Surface Energy Balance ◽

Current Knowledge ◽

Meteorological Data ◽

Reanalysis Data ◽

Balance Model ◽

Thermal Imagery ◽

Thickness Estimation ◽

Miage Glacier

Abstract Surface energy-balance models are commonly used in conjunction with satellite thermal imagery to estimate supraglacial debris thickness. Removing the need for local meteorological data in the debris thickness estimation workflow could improve the versatility and spatiotemporal application of debris thickness estimation. We evaluate the use of regional reanalysis data to derive debris thickness for two mountain glaciers using a surface energy-balance model. Results forced using ERA-5 agree with AWS-derived estimates to within 0.01 ± 0.05 m for Miage Glacier, Italy, and 0.01 ± 0.02 m for Khumbu Glacier, Nepal. ERA-5 data were then used to estimate spatiotemporal changes in debris thickness over a ~20-year period for Miage Glacier, Khumbu Glacier and Haut Glacier d'Arolla, Switzerland. We observe significant increases in debris thickness at the terminus for Haut Glacier d'Arolla and at the margins of the expanding debris cover at all glaciers. While simulated debris thickness was underestimated compared to point measurements in areas of thick debris, our approach can reconstruct glacier-scale debris thickness distribution and its temporal evolution over multiple decades. We find significant changes in debris thickness over areas of thin debris, areas susceptible to high ablation rates, where current knowledge of debris evolution is limited.

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Application of an improved surface energy balance model to two large valley glaciers in the St. Elias Mountains, Yukon

Journal of Glaciology ◽

10.1017/jog.2020.106 ◽

2020 ◽

pp. 1-16

Author(s):

Tim Hill ◽

Christine F. Dow ◽

Eleanor A. Bash ◽

Luke Copland

Keyword(s):

Energy Balance ◽

Surface Energy ◽

Surface Energy Balance ◽

Shortwave Radiation ◽

Balance Model ◽

Landsat 8 ◽

Glacier Surface ◽

Ice Dynamics ◽

Surface Melt

Abstract Glacier surficial melt rates are commonly modelled using surface energy balance (SEB) models, with outputs applied to extend point-based mass-balance measurements to regional scales, assess water resource availability, examine supraglacial hydrology and to investigate the relationship between surface melt and ice dynamics. We present an improved SEB model that addresses the primary limitations of existing models by: (1) deriving high-resolution (30 m) surface albedo from Landsat 8 imagery, (2) calculating shadows cast onto the glacier surface by high-relief topography to model incident shortwave radiation, (3) developing an algorithm to map debris sufficiently thick to insulate the glacier surface and (4) presenting a formulation of the SEB model coupled to a subsurface heat conduction model. We drive the model with 6 years of in situ meteorological data from Kaskawulsh Glacier and Nàłùdäy (Lowell) Glacier in the St. Elias Mountains, Yukon, Canada, and validate outputs against in situ measurements. Modelled seasonal melt agrees with observations within 9% across a range of elevations on both glaciers in years with high-quality in situ observations. We recommend applying the model to investigate the impacts of surface melt for individual glaciers when sufficient input data are available.

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