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Two energy balance closure approaches: applications and comparisons over an oasis-desert ecotone |
Xin PAN1,2, Yuanbo LIU1,*(), Xingwang FAN1, Guojing GAN1 |
1 Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China 2 University of Chinese Academy of Sciences, Beijing 100049, China |
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Abstract Studies of energy balance that rely on eddy covariance (EC) are always challenged by energy balance closure, which is mainly caused by the underestimations of latent heat flux (LE) and sensible heat flux (Hs). The Bowen ratio (BR) and energy balance residual (ER) approaches are two widely-used methods to correct the LE. A comprehensive comparison of those two approaches in different land-use types is essential to accurately correcting the LE and thus improving the EC experiments. In this study, two energy balance approaches (i.e., BR and ER) were compared to correct the LE measured at six EC sites (i.e., three vegetated, one mixed and two non-vegetated sites) in an oasis-desert ecotone of the Heihe River Basin, China. The influences of meteorological factors on those two approaches were also quantitatively assessed. Our results demonstrated that the average energy closure ratio ((LE+Hs)/(Rn-Gs); where Rn is the surface net radiation and Gs is the surface soil heat flux) was approximately close to 1.0 at wetland, maize and village sites, but far from 1.0 at orchard, Gobi and desert sites, indicating a significant energy imbalance at those three latter sites. After the corrections of BR and ER approaches that took into account of soil heat storage, the corrected LE was considerably larger than the EC-measured LE at five of six EC sites with an exception at Gobi site. The BR and ER approaches yielded approximately similar corrected LE at vegetated and mixed sites, but they generated dissimilar results at non-vegetated sites, especially at non-vegetated sites with low relative humidity, strong wind, and large surface-air temperature difference. Our findings provide insight into the applicability of BR and ER approaches to correcting EC-based LE measurements in different land-use types. We recommend that the BR-corrected and ER-corrected LE could be seriously reconsidered as validation references in dry and windy areas.
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Received: 27 January 2016
Published: 31 July 2017
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Corresponding Authors:
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1 | Allen R G, Pereira L S, Howell T A, et al.2011. Evapotranspiration information reporting: I. Factors governing measurement accuracy. Agricultural Water Management, 98(6): 899-920. | 2 | Amiro B.2009. Measuring boreal forest evapotranspiration using the energy balance residual. Journal of Hydrology, 366(1-4): 112-118. | 3 | Aubinet M, Grelle A, Ibrom A, et al.1999. Estimates of the annual net carbon and water exchange of forests: The EUROFLUX methodology. Advances in Ecological Research, 30: 113-175. | 4 | Aubinet M, Vesala T, Papale D.2012. Eddy Covariance: A Practical Guide to Measurement and Data Analysis. Netherlands: Springer, 40-171. | 5 | Baldocchi D, Falge E, Gu L H, et al.2001. FLUXNET: A new tool to study the temporal and spatial variability of ecosystem-scale carbon dioxide, water vapor, and energy flux densities. Bulletin of the American Meteorological Society, 82(11): 2415-2434. | 6 | Barr A G, van der Kamp G, Black T A, et al.2012. Energy balance closure at the BERMS flux towers in relation to the water balance of the White Gull Creek watershed 1999-2009. Agricultural and Forest Meteorology, 153: 3-13. | 7 | Blundell J E, Stubbs R J, Hughes D A, et al.2003. Cross talk between physical activity and appetite control: does physical activity stimulate appetite? Proceedings of the Nutrition Society, 62: 651-661. | 8 | Bowen I S.1926. The ratio of heat losses by conduction and by evaporation from any water surface. Physical Review, 27(6): 779-787. | 9 | Bray G, Bouchard C, Hill J O, et al.2003. Energy expenditure and physical activity. In: Bray G, Bouchard C. Handbook of Obesity (2nd ed.). New York: Marcel Dekker, Inc., 631-654. | 10 | Burba G, Anderson D.2010. Brief Practical Guide to Eddy Covariance Flux Measurements: Principles and Workflow Examples for Scientific and Industrial Applications. Lincoln, Nebraska: LI-COR Biosciences, 11-28. | 11 | Castellví F, Snyder R L, Baldocchi D D.2008. Surface energy-balance closure over rangeland grass using the eddy covariance method and surface renewal analysis. Agricultural and Forest Meteorology, 148(6-7): 1147-1160. | 12 | Foken T.2008. The energy balance closure problem: An overview. Ecological Applications, 18(6): 1351-1367. | 13 | Franssen H J H, St?ckli R, Lehner I, et al.2010. Energy balance closure of eddy-covariance data: A multisite analysis for European FLUXNET stations. Agricultural and Forest Meteorology, 150(12): 1553-1567. | 14 | Haverd V, Cuntz M, Leuning R, et al.2007. Air and biomass heat storage fluxes in a forest canopy: Calculation within a soil vegetation atmosphere transfer model. Agricultural and Forest Meteorology, 147(3-4): 125-139. | 15 | Heusinkveld B G, Jacobs A F G, Holtslag A A M, et al.2004. Surface energy balance closure in an arid region: Role of soil heat flux. Agricultural and Forest Meteorology, 122(1-2): 21-37. | 16 | Hu M G, Wang J H, Ge Y, et al.2015. Scaling flux tower observations of sensible heat flux using weighted area-to-area regression Kriging. Atmosphere, 6(8): 1032-1044. | 17 | Kidston J, Brümmer C, Black T A, et al.2010. Energy balance closure using eddy covariance above two different land surfaces and implications for CO2 flux measurements. Boundary-Layer Meteorology, 136(2): 193-218. | 18 | Kristensen L, Mann J, Oncley S P, et al.1997. How close is close enough when measuring scalar fluxes with displaced sensors? Journal of Atmospheric and Oceanic Technology, 14(4): 814-821. | 19 | Lee X, Massman W, Law B.2004. Handbook of Micrometeorology: A Guide for Surface Flux Measurement and Analysis. Dordrecht: Kluwer Academic Publishers, 181-203. | 20 | Leuning R, van Gorsel E, Massman W J, et al.2012. Reflections on the surface energy imbalance problem. Agricultural and Forest Meteorology, 156: 65-74. | 21 | Li X, Cheng G D, Liu S M, et al.2013. Heihe watershed allied telemetry experimental research (HiWATER): Scientific objectives and experimental design. Bulletin of the American Meteorological Society, 94(8): 1145-1160. | 22 | Li Z L, Tang R L, Wan Z M, et al.2009. A review of current methodologies for regional evapotranspiration estimation from remotely sensed data. Sensors, 9(5): 3801-3853. | 23 | Lindroth A, M?lder M, Lagergren F.2010. Heat storage in forest biomass improves energy balance closure. Biogeosciences, 7(1): 301-313. | 24 | Liu S M, Xu Z W, Wang W Z, et al.2011. A comparison of eddy-covariance and large aperture scintillometer measurements with respect to the energy balance closure problem. Hydrology and Earth System Sciences, 15(4): 1291-1306. | 25 | Liu S M, Xu Z W, Wang W Z.2012. The use of large aperture scintillometer and eddy covariance system for monitoring energy and water vapour fluxes over different surfaces in the Heihe River Basin, China. In: Proceedings of a Symposium Held at Jackson Hole. Wyoming, USA: IAHS-AISH Publication, 184-190. | 26 | Liu Y B, Hiyama T, Yasunari T, et al.2012. A nonparametric approach to estimating terrestrial evaporation: Validation in eddy covariance sites. Agricultural and Forest Meteorology, 157: 49-59. | 27 | Mauder M, Liebethal C, G?ckede M, et al.2006. Processing and quality control of flux data during LITFASS-2003. Boundary-Layer Meteorology, 121(1): 67-88. | 28 | Mauder M, Oncley S P, Vogt R, et al.2007. The energy balance experiment EBEX-2000. Part II: Intercomparison of eddy-covariance sensors and post-field data processing methods. Boundary-Layer Meteorology, 123(1): 29-54. | 29 | McNaughton K G.1983. The direct effect of shelter on evaporation rates: Theory and an experimental test. Agricultural Meteorology, 29(2): 125-136. | 30 | Mercado L M, Bellouin N, Sitch S, et al.2009. Impact of changes in diffuse radiation on the global land carbon sink. Nature, 458(7241): 1014-1018. | 31 | Meyers T P, Hollinger S E.2004. An assessment of storage terms in the surface energy balance of maize and soybean. Agricultural and Forest Meteorology, 125(1-2): 105-115. | 32 | Moiwo J P, Tao F L.2015. Contributions of precipitation, irrigation and soil water to evapotranspiration in (semi)-arid regions. International Journal of Climatology, 35(6): 1079-1089. | 33 | Moncrieff J B, Massheder J M, de Bruin H, et al.1997. A system to measure surface fluxes of momentum, sensible heat, water vapour and carbon dioxide. Journal of Hydrology, 188-189: 589-611. | 34 | Nagol J R, Vermote E F, Prince S D.2009. Effects of atmospheric variation on AVHRR NDVI data. Remote Sensing of Environment, 113(2): 392-397. | 35 | Oliphant A J, Grimmond C S B, Zutter H N, et al.2004. Heat storage and energy balance fluxes for a temperate deciduous forest. Agricultural and Forest Meteorology, 126(3-4): 185-201. | 36 | Oncley S P, Foken T, Vogt R, et al.2007. The energy balance experiment EBEX-2000. Part I: Overview and energy balance. Boundary-Layer Meteorology, 123(1): 1-28. | 37 | Richardson A D, Hollinger D Y, Burba G G, et al.2006. A multi-site analysis of random error in tower-based measurements of carbon and energy fluxes. Agricultural and Forest Meteorology, 136(1-2): 1-18. | 38 | Schotanus P, Nieuwstadt F T M, De Bruin H A R.1983. Temperature measurement with a sonic anemometer and its application to heat and moisture fluxes. Boundary-Layer Meteorology, 26(1): 81-93. | 39 | Smith D M, Jarvis P G, Odongo J CW.1997. Energy budgets of windbreak canopies in the Sahel. Agricultural and Forest Meteorology, 86(1-2): 33-49. | 40 | Squires G L.2001. Practical Physics. Cambridge: Cambridge University Press, 1-41. | 41 | Stoy P C, Mauder M, Foken T.2013. A data-driven analysis of energy balance closure across FLUXNET research sites: The role of landscape scale heterogeneity. Agricultural and Forest Meteorology, 171-172: 137-152. | 42 | Twine T E, Kustas W P, Norman J M, et al.2000. Correcting eddy-covariance flux underestimates over a grassland. Agricultural and Forest Meteorology, 103(3): 279-300. | 43 | Verstraeten W W, Veroustraete F, Feyen J.2008. Assessment of evapotranspiration and soil moisture content across different scales of observation. Sensors, 8(1): 70-117. | 44 | Wang J M, Wang W Z, Liu S M, et al.2009. The problems of surface energy balance closure-an overview and case study. Advances in Earth Science, 24(7): 705-713. (in Chinese) | 45 | Wang J M, Zhuang J X, Wang W Z, et al.2015. Assessment of uncertainties in eddy covariance flux measurement based on intensive flux matrix of HiWATER-MUSOEXE. IEEE Geoscience and Remote Sensing Letters, 12(2): 259-263. | 46 | Wang K C, Dickinson R E.2012. A review of global terrestrial evapotranspiration: Observation, modeling, climatology, and climatic variability. Reviews of Geophysics, 50(2): RG2005, doi: 10.1029/2011RG000373. | 47 | Webb E K, Pearman G I, Leuning R.1980. Correction of flux measurements for density effects due to heat and water vapour transfer. Quarterly Journal of the Royal Meteorological Society, 106(447): 85-100. | 48 | Wilczak J M, Oncley S P, Stage S A.2001. Sonic anemometer tilt correction algorithms. Boundary-Layer Meteorology, 99(1): 127-150. | 49 | Wild M.2008. Short-wave and long-wave surface radiation budgets in GCMs: a review based on the IPCC-AR4/CMIP3 models. Tellus A, 60(5): 932-945. | 50 | Wilson K, Goldstein A, Falge E, et al.2002. Energy balance closure at FLUXNET sites. Agricultural and Forest Meteorology, 113(1-4): 223-243. | 51 | Wohlfahrt G, Haslwanter A, H?rtnagl L, et al.2009. On the consequences of the energy imbalance for calculating surface conductance to water vapour. Agricultural and Forest Meteorology, 149(9): 1556-1559. | 52 | Xu Z W, Liu S M, Li X, et al.2013. Intercomparison of surface energy flux measurement systems used during the HiWATER-MUSOEXE. Journal of Geophysical Research, 118(23): 13140-13157. | 53 | Yang K, Wang J M.2008. A temperature prediction-correction method for estimating surface soil heat flux from soil temperature and moisture data. Science in China series D: Earth sciences, 51(5): 721-729. | 54 | Zeweldi D A, Gebremichael M, Wang J M, et al.2010. Intercomparison of sensible heat flux from large aperture scintillometer and eddy covariance methods: Field experiment over a homogeneous semi-arid region. Boundary-Layer Meteorology, 135(1): 151-159. |
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