Abstract
Radiation is a major driver to the carbon, water, and energy exchanges of an ecosystem. For local radiation balance measurements, one essential question is whether the measurement systems should be installed horizontally or parallel to inclined slope surface. With a case study over a temperate deciduous forest on a moderate inclined (9°) northwest-facing slope, we quantified the slope effect on net radiation (Rn) and its components and the energy balance closure measured by an eddy covariance (EC) system. Compared with the slope-parallel radiometer, the horizontal sensor overestimated the incident solar radiation (SR) by 7%, the incoming photosynthetically active radiation (PAR) by 1.5%, and the incoming near-infrared radiation (NIR) by 10%; while underestimated the reflected shortwave radiation (SR) by 4% and NIR by 5%. The influence of radiometer-orientation on incoming longwave radiation (LR) was about 3%, while that on outgoing LR was negligible. Summing all these components, horizontal sensor overestimated the Rn by 9%. Converting the horizontally-measured incident radiation to slope-surface reduced a half of the biases on incoming SR and Rn. Measuring the Rn with slope-parallel radiometer and correcting the slope-effect on horizontally-measured incident SR improved the energy balance ratio (EBR) by 8% and 5%, respectively. A mini-review indicated that, the horizontal sensor underestimated (overestimated) the EBR on north-facing (south-facing) slopes in temperate zone in the Northern Hemisphere, with an inclination angular sensitivity of EBR as high as 1.17% per degree of inclination angle. We recommend measuring radiations on inclined terrains with slope-parallel radiometers, or correcting at least for the incident SR in energy balance studies.
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References
Alados I, Alados-Arboledas L (1999) Direct and diffuse photosynthetically active radiation: measurements and modelling. Agr Forest Meteorol 93(1): 27–38. https://doi.org/10.1016/S0168-1923(98)00107-5
Aubinet M, Vesala T, Papale D (2012) Eddy covariance: a practical guide to measurement and data analysis. Springer.
Bai J, Zong X. (2021) Global solar radiation transfer and its loss in the atmosphere. Appl Sci-Basel 11(6): 2651. https://doi.org/10.3390/app11062651
Bala G, Caldeira K, Wickett M, et al. (2007) Combined climate and carbon-cycle effects of large-scale deforestation. P Natl Acad Sci USA 104(16): 6550–6555. https://doi.org/10.1073/pnas.0608998104
Baldocchi D, Falge E, Gu L, 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. B Am Meteorol Soc 82(11): 2415–2434. https://doi.org/10.1175/1520-0477(2001)082<2415:FANTTS>2.3.CO;2
Barr AG, Morgenstern K, Black TA, et al. (2006) Surface energy balance closure by the eddy-covariance method above three boreal forest stands and implications for the measurement of the CO2 flux. Agr Forest Meteorol 140(1): 322–337. https://doi.org/10.1016/j.agrformet.2006.08.007
Barry RG (2008) Mountain Weather and Climate 3e. Cambridge University Press.
Finnigan JJ, Clement R, Malhi Y, et al. (2003) A re-evaluation of long-term flux measurement techniques part I: averaging and coordinate rotation. Bound-Lay Meteorol 107(1): 1–48. https://doi.org/10.1023/A:1021554900225
Frank JM, Massman WJ, Ewers BE (2013) Underestimates of sensible heat flux due to vertical velocity measurement errors in non-orthogonal sonic anemometers. Agr Forest Meteorol 171–172: 72–81. https://doi.org/10.1016/j.agrformet.2012.11.005
Gueymard CA, Ruiz-Arias JA (2016) Extensive worldwide validation and climate sensitivity analysis of direct irradiance predictions from 1-min global irradiance. Sol Energy 128: 1–30. https://doi.org/10.1016/j.solener.2015.10.010
Hammerle A, Haslwanter A, Schmitt M, et al. (2007) Eddy covariance measurements of carbon dioxide, latent and sensible energy fluxes above a meadow on a mountain slope. Bound-Lay Meteorol 122(2): 397–416. https://doi.org/10.1007/s10546-006-9109-x
Hiller R, Zeeman MJ, Eugster W (2008) Eddy-covariance flux measurements in the complex terrain of an alpine valley in Switzerland. Bound-Lay Meteorol 127(3): 449–467. https://doi.org/10.1007/s10546-008-9267-0
Hoch SW, Whiteman CD (2010) Topographic effects on the surface radiation balance in and around Arizona’s Meteor Crater. J Appl Meteorol Clim 49(6): 1114–1128. https://doi.org/10.1175/2010JAMC2353.1
Hoch SW, Whiteman CD, Mayer B (2011) A systematic study of longwave radiative heating and cooling within valleys and basins using a three-dimensional radiative transfer model. J Appl Meteorol Clim 50(12): 2473–2489. https://doi.org/10.1175/JAMC-D-11-083.1
Holst T, Rost J, Mayer H (2005) Net radiation balance for two forested slopes on opposite sides of a valley. Int J Biometeorol 49(5): 275–284. https://doi.org/10.1007/s00484-004-0251-1
Jacovides CP, Tymvios FS, Assimakopoulos VD, et al. (2006) Comparative study of various correlations in estimating hourly diffuse fraction of global solar radiation. Renew Energ 31(15): 2492–2504. https://doi.org/10.1016/j.renene.2005.11.009
Jarvis PG, Massheder JM, Hale SE, et al. (1997) Seasonal variation of carbon dioxide, water vapor, and energy exchanges of a boreal black spruce forest. J Geophysical Res-Atmos 102(D24): 28953–28966. https://doi.org/10.1029/97JD01176
Jung M, Reichstein M, Ciais P, et al. (2010) Recent decline in the global land evapotranspiration trend due to limited moisture supply. Nature 467(7318): 951–954. https://doi.org/10.1038/nature09396
Jung M, Reichstein M, Margolis HA, et al. (2011) Global patterns of land-atmosphere fluxes of carbon dioxide, latent heat, and sensible heat derived from eddy covariance, satellite, and meteorological observations. J Geophysical Res-Biogeo 116(G3): G00J07 https://doi.org/10.1029/2010JG001566
Leuning R, van Gorsel E, Massman WJ, et al. (2012) Reflections on the surface energy imbalance problem. Agr Forest Meteorol 156: 65–74. https://doi.org/10.1016/j.agrformet.2011.12.002
Liang S, Shuey CJ, Russ AL, et al. (2003) Narrowband to broadband conversions of land surface albedo: II. Validation. Remote Sens Environ 84(1): 25–41. https://doi.org/10.1016/S0034-4257(02)00068-8
Liu, BYH, Jordan RC (1963) The long-term average performance of flat-plate solar-energy collectors: With design data for the U.S., its outlying possessions and Canada. Sol Energy 7(2): 53–74. https://doi.org/10.1016/0038-092X(63)90006-9
Liu F, Wang X, Wang C, et al. (2021a) Environmental and biotic controls on the interannual variations in CO2 fluxes of a continental monsoon temperate forest. Agr Forest Meteorol 296: 108232. https://doi.org/10.1016/j.agrformet.2020.108232
Liu F, Wang C, Wang X (2021b) Sampling protocols of specific leaf area for improving accuracy of the estimation of forest leaf area index. Agr Forest Meteorol 298–299: 108286. https://doi.org/10.1016/j.agrformet.2020.108286
Matzinger N, Andretta M, Van Gorsel E, et al. (2003) Surface radiation budget in an Alpine valley. Q J Roy Meteor Soc 129(588): 877–895. https://doi.org/10.1256/qj.02.44
Moderow U, Grünwald T, Queck R, et al. (2021) Energy balance closure and advective fluxes at ADVEX sites. Theor Appl Climatol 143(1): 761–779. https://doi.org/10.1007/s00704-020-03412-z
Olmo FJ, Vidan J, Foyon I, et al. (1999) Prediction of global irradiance on inclined surfaces from horizontal global irradiance. Energy 24(8): 689–704. https://doi.org/10.1016/S0360-5442(99)00025-0
Ross J, Sulev M (2000) Sources of errors in measurements of PAR. Agr Forest Meteorol 100(2–3): 103–125. https://doi.org/10.1016/S0168-1923(99)00144-6
Rotach, Mathias W, Wohlfahrt G, et al. (2014) The world is not flat: Implications for the global carbon balance. B Am Meteorol Soc 95(7): 1021–1028. https://doi.org/10.1175/bams-d-13-00109.1
Schimel D, Pavlick R, Fisher JB, et al. (2015) Observing terrestrial ecosystems and the carbon cycle from space. Global Change Biol 21(5): 1762–1776. https://doi.org/10.1111/gcb.12822
Sellers PJ, Randall DA, Collatz GJ, et al. (1996) A Revised Land Surface Parameterization (SiB2) for Atmospheric GCMS. Part I: Model Formulation. J Climate 9(4): 676–705. https://doi.org/10.1175/1520-0442(1996)009<0676:arlspf>2.0.co;2
Serrano-Ortiz P, Sánchez-Cañete EP, Olmo FJ, et al. (2016) Surface-parallel sensor orientation for assessing energy balance components on mountain slopes. Bound-Lay Meteorol 158(3): 489–499. https://doi.org/10.1007/s10546-015-0099-4
Spitters CJT (1986) Separating the diffuse and direct component of global radiation and its implications for modeling canopy photosynthesis Part II. Calculation of canopy photosynthesis. Agr Forest Meteorol 38(1–3): 231–242. https://doi.org/10.1016/0168-1923(86)90061-4
Spitters CJT, Toussaint HAJM, Goudriaan J (1986) Separating the diffuse and direct component of global radiation and its implications for modeling canopy photosynthesis Part I. Components of incoming radiation. Agr Forest Meteorol 38(1–3): 217–229. https://doi.org/10.1016/0168-1923(86)90060-2
Stoy, PC, Mauder M, Foken T, et al. (2013) A data-driven analysis of energy balance closure across FLUXNET research sites: The role of landscape scale heterogeneity. Agr Forest Meteorol 171: 137–152. https://doi.org/10.1016/j.agrformet.2012.11.004
Sun J (2007) Tilt corrections over complex terrain and their implication for CO2 transport. Bound-Lay Meteorol 124(2): 143–159. https://doi.org/10.1007/s10546-007-9186-5
Trenberth KE, Fasullo JT, and Kiehl J (2009) Earth’s global energy budget. B Am Meteorol Soc 90(3): 311–323. https://doi.org/10.1175/2008BAMS2634.1
Twine TE, Kustas WP, Norman JM, et al. (2000) Correcting eddy-covariance flux underestimates over a grassland. Agr Forest Meteorol 103(3): 279–300. https://doi.org/10.1016/S0168-1923(00)00123-4
Wang Q, Tenhunen J, Schmidt M, et al. (2005) Diffuse PAR irradiance under clear skies in complex alpine terrain. Agr Forest Meteorol 128(1–2): 1–15. https://doi.org/10.1016/j.agrformet.2004.09.004
Wang X, Wang C (2016) Effects of coordinate rotations on eddy fluxes over a forest on a mountainous terrain in Northeast China. Chinese J Appl Ecol 27(9): 2779–2788. (In Chinese) https://doi.org/10.13287/j.1001-9332.201609.012
Wang X, Wang C, Guo Q, et al. (2016) Improving the CO2 storage measurements with a single profile system in a tall-dense-canopy temperate forest. Agr Forest Meteorol 228–229: 327–338. https://doi.org/10.1016/j.agrformet.2016.07.020
Wang, X, Wang C, Li Q (2015) Wind regimes above and below a temperate deciduous forest canopy in complex terrain: Interactions between slope and valley winds. Atmosphere-Basel 6(1): 60–87. https://doi.org/10.3390/atmos6010060
Warton DI, Wright IJ, Falster DS, et al. (2006) Bivariate line-fitting methods for allometry. Biol Rev 81(2): 259–291. https://doi.org/10.1017/S1464793106007007
Weiss A, Norman JM (1985) Partitioning solar radiation into direct and diffuse, visible and near-infrared components. Agr Forest Meteorol 34(2): 205–213. https://doi.org/10.1016/0168-1923(85)90020-6
Whiteman CD, Allwine KJ, Fritschen LJ, et al. (1989) Deep valley radiation and surface energy budget microclimates. Part I: Radiation. J Appl Meteorol 28(6): 414–426.
Wilson K, Goldstein A, Falge E, et al. (2002) Energy balance closure at FLUXNET sites. Agr Forest Meteorol 113(1–4): 223–243. https://doi.org/10.1016/S0168-1923(02)00109-0
Wohlfahrt G, Hammerle A, Niedrist G, et al. (2016) On the energy balance closure and net radiation in complex terrain. Agr Forest Meteorol 226: 37–49. https://doi.org/10.1016/j.agrformet.2016.05.012
Xu K, Xing Y, Chang X (2021) Model optimization and gpp estimation of light energy utilization in subtropical evergreen coniferous forest. For Eng 37(1): 28–36. (In Chinese) https://doi.org/10.16270/j.cnki.slgc.2021.05.013
Yan H, Wang S, Dai J, et al. (2021) Forest greening increases land surface albedo during the main growing period between 2002 and 2019 in China. J Geophysical Res-Atmos 126(6): e2020JD033582. https://doi.org/10.1029/2020jd033582
Yang D (2016) Solar radiation on inclined surfaces: Corrections and benchmarks. Sol Energy 136(Supplement C): 288–302. https://doi.org/10.1016/j.solener.2016.06.062
Zitouna-Chebbi R, Prévot L, Jacob F, et al. (2012) Assessing the consistency of eddy covariance measurements under conditions of sloping topography within a hilly agricultural catchment. Agr Forest Meteorol 164: 123–135. https://doi.org/10.1016/j.agrformet.2012.05.010
Acknowledgments
We thank Georg Wohlfahrt, Penelope Serrano-Ortiz, Werner Eugster, and Ana López-Ballesteros for providing the data of energy balance ratio at their sites. This research was supported by the National Natural Science Foundation of China (32171765 and 41503071) and the Program for Changjiang Scholars and Innovative Research Team in University (IRT_15R09). The Maoershan Forest Ecosystem Research Station provided field logistic support.
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Wang, Xc., Liu, F. & Wang, Ck. Radiation and energy balance on a hillslope forest: horizontal versus slope-parallel installation of radiometer. J. Mt. Sci. 19, 3076–3087 (2022). https://doi.org/10.1007/s11629-022-7481-8
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DOI: https://doi.org/10.1007/s11629-022-7481-8